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PROCEEDINGS | 1889<strong>Proceedings</strong> <strong>of</strong> a <strong>Workshop</strong>on the Development <strong>of</strong> aGenetic Improvement Programfor African Catfish ClariasgariepinusEdited by R.W. Ponzoni and N.H. NguyenReducing poverty and hunger by improving fisheries and aquaculturewww.worldfishcenter.org

<strong>Proceedings</strong> <strong>of</strong> a <strong>Workshop</strong> on theDevelopment <strong>of</strong> a Genetic ImprovementProgram for African Catfish ClariasgariepinusAccra, Ghana, 5-9 November 2007Edited byRaul W. PonzoniNguyen Hong NguyenThe WorldFish Center2008

This document should be cited as:Ponzoni, R.W. and N.H. Nguyen (eds). 2008. <strong>Proceedings</strong> <strong>of</strong> a <strong>Workshop</strong> on the Development<strong>of</strong> a Genetic Improvement Program for African catfish Clarias gariepinus. WorldFish CenterConference <strong>Proceedings</strong> Number 1889. The WorldFish Center, Penang, Malaysia. 130 p.Editors’ affiliations:Raul W. Ponzoni: The WorldFish Center, Penang, MalaysiaNguyen Hong Nguyen: The WorldFish Center, Penang, MalaysiaISBN: 978-983-2346-68-5WorldFish Center Contribution Number: 1889Cover photograph (front): Dr. Randall Brummett(rear): Dr. Mahmoud RezkLayout and design by: CIMMYTPrinted by: Delimax (M) Sdn. Bhd., PenangA PDF copy <strong>of</strong> the publication is available from: www.worldfishcenter.org© 2008 The WorldFish CenterPublished by: The WorldFish Center, P.O. Box 500 GPO, Penang, MalaysiaAll rights reserved. This publication may be reproduced in whole or in part and in any form foreducational or nonpr<strong>of</strong>it purposes without the permission <strong>of</strong> the copyright holders providedthat due acknowledgement <strong>of</strong> the source is given. This publication may not be copied ordistributed electronically for resale or other commercial purposes without prior permission, inwriting, from The WorldFish Center. To obtain permission, contact the Business Developmentand Communications Division, worldfishcenter@cgiar.org.The WorldFish Center is one <strong>of</strong> the 15 international research centers <strong>of</strong> theConsultative Group on International Agricultural Research (CGIAR) that hasinitiated the public awareness campaign, Future Harvest.

CONTENTSIntroduction 1The workshop 1The workshop outputs 3Closing remarks 4Country reviews and reportsCameroon 6Egypt 15Ghana 23Kenya 33Malawi 42Nigeria 49Uganda 57Keynotes papersBiology and biodiversity <strong>of</strong> African catfish 64Catfish production and reproduction 73Catfish nutrition and feeds 79Catfish in aquaculture: pros and cons 82Principles <strong>of</strong> genetic improvement for catfish 89Genetic improvement program in Abbassa, Egypt 96Prospects for the development <strong>of</strong> genetic improvement program in catfish 104ANNEXESA. List <strong>of</strong> participants 116B. The workshop program 119C. Opening Statement and Welcome Address by Dr. Yaw Opoku Ankomah, 121Director <strong>of</strong> CSIR-WRID. Speech <strong>of</strong> Dr. Kwame Boa-Amponsem, Former Deputy DirectorGeneral <strong>of</strong> CSIR 123E. Format for group discussions and presentation 124F. Unified report (Concept note) 126

ivLIST OF ABBREVIATIONS AND ACRONYMSLIST OF ABBREVIATIONS AND ACRONYMSADBADCPADiMAFWAAGCDAgSSIPAIFPARACARDCARDECBOMOSACEPIDCFACIDCIFACIPCLOFFACRIRPCSIRDFIDDIRPECDOCADOFEACEADEEZEUFAOFCFFTFCFMTFDFISHFPCGAFRDG x EGIFTIAAIABICLARMAgriculture Development Bank, GhanaAfrican Development Center for AquacultureAquaculture Development in MalawiAfrican Water Association, KenyaGeneral Administration for Cooperation and Development, Belgium;(Administration Générale de la Coopération au Développement)Agricultural Sub-sector Capacity Building Project, GhanaAquaculture and Inland Fisheries Project, NigeriaAfrican Regional Aquaculture CenterAquaculture Research and Development Center, Kajjansi, UgandaAquaculture Research and Development Center, Akosombo, GhanaResearch project pioneering small-scale fish farming in threecountries in East Africa: Ethiopia, Kenya and UgandaCenter <strong>of</strong> Excellence for Production Innovation and Development; (Centred’Excellence pour la Production l’Innovation et le Développement)Communauté Financière Africaine (African Financial Community)Commercialization and Information DivisionCentral Institute <strong>of</strong> Freshwater AquacultureConstruction des Innovations en PartenariatChecklist <strong>of</strong> the Freshwater Fishes <strong>of</strong> AfricaProject <strong>of</strong> the Foundation for Research Development(CRIR) at the University <strong>of</strong> Pretoria, South AfricaCouncil for Scientific and Industrial Research, GhanaU.K. Department for International Development, LondonDepartment <strong>of</strong> Fisheries <strong>of</strong> MINEPIA, CameroonDesoxycorticosterone acetateDirectorate <strong>of</strong> Fisheries, Ghana (former name <strong>of</strong> Ministry <strong>of</strong> Fisheries)East African CommunityEnvironmental Affairs Department, MalawiExclusive economic zoneEuropean Union, Brussels, BelgiumFood and Agriculture Organization <strong>of</strong> the United Nations, Rome, ItalyFederal College <strong>of</strong> Freshwater Fisheries Technology,New Bussa and Baga, NigeriaFederal College <strong>of</strong> Fisheries and Marine Technology, Lagos, NigeriaFisheries Department, KenyaFisheries Investment for Sustainable Harvest (a USAID-fundedproject in Uganda implemented by Aurban University)Fry production center, KenyaGeneral Authority for Fisheries Resources Development, EgyptGenotype by environment (or genotype x environment)Genetically improved farmed tilapiaIntegrated aquaculture-agricultureInstitute <strong>of</strong> Aquatic Biology, Ghana (former name <strong>of</strong> the present CSIR-WRI)International Center for Living Aquatic ResourcesManagement (now The WorldFish Center)

LIST OF ABBREVIATIONS AND ACRONYMSvIDRC International Development Research Centre, Ottawa, CanadaIFC International Finance CooperationIITA International Institute <strong>of</strong> Tropical Agriculture, CameroonIMF International Monetary Fund, Washington, D.C.INGA International Network on Genetics in AquacultureIRAD Institute <strong>of</strong> Agricultural Research for Development, Cameroon (Institutde Recherche Agricole pour le Développement de Cameroun)JICA Japanese International Cooperation Agency, TokyoKMFRI Kenya Marine and Fisheries Research InstituteKNUST Kwame Nkrumah University <strong>of</strong> Science and Technology, Kumasi, GhanaKUL Katholieke Universiteit Leuven, BelgiumLBDA Lake Basin Development Authority, KenyaMAAIF Ministry <strong>of</strong> Agriculture, Animal Industries and Fisheries, Uganda; (Ministèrede l’Agriculture, des Industries Animales et des Pêches de Uganda)MALDECO Private company producing tilapia feed in MalawiMINEPIA Ministry <strong>of</strong> Livestock, Fisheries and Animal Industries, Cameroon; (Ministèrede l’Élevage des Pêches et des Industries Animales de Cameroun)MINRESI Ministry <strong>of</strong> Scientific Research and Innovation, Cameroon; (Ministèrede la Recherche Scientifique et de l’Innovation de Cameroun)MoFi Ministry <strong>of</strong> Fisheries, Ghana (formerly the Directorate <strong>of</strong> Fisheries)NARES National aquatic research and extension systemsNARS National aquatic research systemNEPAD New Partnership for Africa’s DevelopmentNGO Non-governmental organizationNIFFR National Institute for Freshwater Fisheries Research, New Bussa, NigeriaNIOMR Nigerian Institute for Oceanography and Marine ResearchNSPFS Nigerian Special Programme for Food SecurityNUVITA Private company manufacturing fish feeds for onefish farm (Source <strong>of</strong> the Nile) in UgandaORSTOM Office de la Recherche Scientific et Technique Outre-Mer, Paris, FrancePNVRA National Agricultural Research and Extension Program, CameroonPPP Public-private partnershipR & D Research and developmentRDE Research, development and extensionREPARAC La Recherche Agronomique au CamerounSEAPB Service d’Études et d’Appui aux Populations à la Base (NGO in Cameroon)SME Small and medium-sized enterprisesSSA Sub-Saharan AfricaTOT Training <strong>of</strong> trainersUNDP United Nations Development Programme, New YorkUSAID United States Agency for International Development, Washington, D.C.World Bank The World Bank, Washington, D.C.WorldFish The WorldFish Center, Penang, Malaysia (formerly ICLARM)WRI Water Research Institute, GhanaWRRI Water Resources Research Institute, Ghana (former name <strong>of</strong> WRI)WRS Water recirculation systemNote: All references to dollars ($) in this publication refer to US dollars.

viFOREWORDFOREWORDIn recent years African catfish (Clarias gariepinus) production has gained considerableimportance in a number <strong>of</strong> countries on the continent. The species has several desirableattributes that make it attractive when aquaculture development is considered. It is highlysuitable for farming because it is easy to reproduce, it does not require specialized feed,it tolerates high stocking densities and grows rapidly under these conditions, it acceptsartificial feed, it tolerates poor water quality, and very importantly, it is highly sought afterin local markets and economically viable in pond production systems. Clarias gariepinus isendemic to Africa.Following consultation with African partners The WorldFish Center organized a workshopon the specific topic ‘Development <strong>of</strong> a genetic improvement program for catfish – Clariasgariepinus’. The workshop was held from 5 to 9 November 2007 in Accra, Ghana. TheWater Research Institute (WRI) was the host organization in Ghana.The participants at the workshop were persons directly involved in work with the species.Both government and non-government personnel were invited to attend and were presentat the workshop.The workshop objectives were as follows:1.2.3.To review the state <strong>of</strong> the catfish industry in Africa (participants were asked to make apresentation on the state <strong>of</strong> the industry in their own country)To present a series <strong>of</strong> keynote papers in the areas <strong>of</strong>:Catfish reproductive management and grow outCatfish nutrition and feedsThe application <strong>of</strong> genetic principles to catfish genetic improvement programsBased on the information presented above the participants were encouraged todevelop recommendations on how to best approach the issue <strong>of</strong> genetic improvementprograms for catfish. These recommendations have been consolidated in the presentworkshop proceedings, and they will be used in the future to jointly develop proposalson the establishment <strong>of</strong> catfish genetic improvement programs in Africa. We aredelighted to present these proceedings to you.Finally, we would like to use the opportunity to thank the Water Research Institute (Council forScientific and Industrial Research) for hosting the workshop in Accra, Ghana. In particular,we would like to thank Dr Felix Attipoe and Mr Seth Agyakwa for their extraordinary input intothe organization <strong>of</strong> the event and for the hospitality they displayed during the participants’stay in Ghana. Funding for the workshop was provided by the European Union (EU).Dr Raul W. PonzoniDr Nguyen Hong Nguyen

INTRODUCTION 1INTRODUCTIONClarias gariepinus is the second mostimportant freshwater fish (after tilapia) inAfrica — with the exception <strong>of</strong> Nigeria whereproduction <strong>of</strong> African catfish far exceeds that<strong>of</strong> tilapia and accounts for 70–80 percent<strong>of</strong> the total freshwater fish production inthe country. Despite the high potential forproduction <strong>of</strong> this species, the industry onthis continent has not been well established,and is generally in a very immature stage.One <strong>of</strong> the critical limiting factors has been aserious lack <strong>of</strong> good quality seed to supplyfarmers and producers. This has resultedfrom the poor performance <strong>of</strong> availablelocal brood stock and poor managementpractices at hatcheries, as well as thenon-existence <strong>of</strong> any appropriate breedingstructure or improved strains.Other constraints that have resulted in lowproductivity <strong>of</strong> C. gariepinus in existingfarming systems in Africa include difficultieswith induced male reproduction, low survivalrates during the larvae rearing stage,inefficient utilization <strong>of</strong> local feedstuff, lack<strong>of</strong> least-cost optimal balanced diets, poormanagement practices, and immature postharvest(processing) industry and marketingsystems. There are also concerns aboutthe development <strong>of</strong> catfish production inrelation to environmental protection, geneticresource conservation, genetic biodiversity,and the future sustainability <strong>of</strong> the industry.In view <strong>of</strong> the current state <strong>of</strong> catfishproduction, and as part <strong>of</strong> a program<strong>of</strong> research and capacity building foraquaculture development in Africa, aworkshop on “The development <strong>of</strong> a geneticimprovement program for African catfish -Clarias gariepinus” was held in Accra, Ghanafrom 5 to 9 November 2007. Convened bythe Water Research Institute (WRI) and theWorldFish Center, the workshop broughttogether participants from eight major catfishproducing countries in Africa to discuss thetechnical constraints, the challenges andthe opportunities that they face.The workshop started with country reportspresenting an overview <strong>of</strong> the current state<strong>of</strong> catfish production and research, andwas followed by a series <strong>of</strong> keynote paperscovering a wide range <strong>of</strong> topics from basicbiology to modern genetic technologiessuited to future selective breeding programsfor this species. The workshop included afield trip to catfish farms and provided anopen forum for group discussions. Theprogram <strong>of</strong> the workshop is described in thefollowing section.THE WORKSHOPTHE WORKSHOP OPENINGThe workshop was <strong>of</strong>ficially opened onthe morning <strong>of</strong> Monday the 5 th November2007 by Dr. Yaw Opoku-Ankomah, Director<strong>of</strong> the Council for Scientific and IndustrialResearch Water Research Institute (CSIR-WRI) <strong>of</strong> Ghana. This was followed byintroductory remarks by the chairman, Dr.Kwame Boa-Amponsem, Former DeputyDirector General <strong>of</strong> CSIR (Annex D). Mr.K<strong>of</strong>i Agbogah, a research scientist at WRI,facilitated the introduction <strong>of</strong> workshopparticipants before inviting the Director <strong>of</strong>CSIR-WRI to make the opening address.Dr. Yaw Opoku-Ankomah welcomed theparticipants to CSIR-WRI, Ghana, andbriefed them on the history, structure,organization and mission <strong>of</strong> CSIR-WRI. Healso stressed the long-term cooperationbetween the WorldFish and CSIR-WRI.During the 1980s, CSIR-WRI played a veryactive role in providing tilapia germplasmfor the genetically improved farmed tilapia(GIFT) project. The on-going geneticimprovement program in local indigenousNile tilapia at the Aquaculture Research andDevelopment Center <strong>of</strong> WRI at Akosombohas been implemented with substantialinputs from the WorldFish Center. Theimproved “Akosombo” tilapia strain hasgained popularity and is beginning to makea significant contribution to aquaculture inGhana. Finally, Dr. Yaw Opoku-Ankomahexpressed his appreciation to WorldFish fortheir partnership and support (Annex C).Dr. Raul Ponzoni, Senior Scientist andProgram Leader (Geneticist) <strong>of</strong> theWorldFish Center, thanked the Director <strong>of</strong>CSIR-WRI for his informative and supportive

2 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSopening address before making some briefopening remarks. Dr. Ponzoni highlightedthe workshop’s objectives and agenda,the format for discussions in groups andfor presentations (Annex D). He also notedsome housekeeping rules and the workshopprocess. In particular, Dr. Ponzoni stressedthe need to bring experts from partnercountries in the region to the workshop,and its importance in identifying technicalconstraints encountered in the catfishindustry. The inputs from the participantswould be a pre-requisite for the formulation<strong>of</strong> recommendations to develop a regionalprogram for genetic improvement in C.gariepinus. He also expected all participantsto work hard and contribute their wealth<strong>of</strong> experience to achieve the workshop’sobjectives. Finally, Dr. Ponzoni wished theworkshop to be fruitful and successful.THE PARTICIPANTSA total <strong>of</strong> 36 participants from researchinstitutions, universities, departments <strong>of</strong>fisheries, and fish farmer associationsfrom eight African countries (Cameroon,Egypt, Ghana, Kenya, Malawi, Nigeria,South Africa and Uganda) attended theworkshop. The majority <strong>of</strong> the participantshad a strong technical background andextensive experience in catfish researchand production in their respectivecountries. Some participants came fromother disciplines such as aquatic biology,aquaculture, economics, and businessadministration. A number <strong>of</strong> postgraduatestudents from Nigeria took the opportunityto attend the workshop. There were alsoexperts from Israel and commercial fishproducers from the Netherlands. A fulllist <strong>of</strong> participants and details <strong>of</strong> theircorrespondence addresses is provided inAnnex A.THE AGENDAThe workshop had the following threeobjectives:i) To review the state <strong>of</strong> the catfish industryin Africa as well as research issues andfuture research priorities on Clariasgariepinus;ii) To present a series <strong>of</strong> keynote papers inthe areas <strong>of</strong> biology and genetic diversity<strong>of</strong> African catfish, production andreproduction management, catfishnutrition and feeds, the application <strong>of</strong>genetic principles to catfish geneticimprovement programs, the WorldFishCenter’s genetic improvement programin Abbassa, Egypt, and potentialapplication <strong>of</strong> molecular information andreproductive technologies in practicalbreeding programs; andParticipants at the workshop on the development <strong>of</strong> a genetic improvement program for Africancatfi sh Clarias gariepinus in Accra, Ghana 5-9 November 2007.

INTRODUCTION 3iii) To develop recommendations on howbest to approach the issue <strong>of</strong> geneticimprovement programs for catfish.Details <strong>of</strong> the workshop agenda are givenin Annex B. The main activities <strong>of</strong> theworkshop included presentations <strong>of</strong> countryreviews and reports, keynote papers, aone-day field trip, group discussions anda synthesized report under the format <strong>of</strong>WorldFish concept note development.THE OUTPUTSOverall, the workshop provided a very goodopportunity to exchange information aboutthe catfish industry in different Africancountries. There were also opportunitiesto exchange practical experiences withthe invited speakers and among otherparticipants. A one-day field trip allowedparticipants to visit farms and hatcheries,and get close to the real productionenvironment. The group discussions whichcapped the workshop provided an idealforum for the final debate and the formulation<strong>of</strong> recommendations regarding the activitiesto be undertaken for further progress. Abrief concept note was also developedand distributed to all the participants. Therecommendations emanating from theworkshop will be used to jointly developproposals on the establishment <strong>of</strong> catfishgenetic improvement programs in Africa.COUNTRY REVIEWSThe seven country reviews provideinformation on the current state <strong>of</strong> catfishproduction (by year and region within eachcountry), the existing industry structure(scale and mode <strong>of</strong> production <strong>of</strong> breedingcenters, hatcheries, and <strong>of</strong> catfish farmersand producers), existing productionconditions and farming systems <strong>of</strong> Africancatfish, marketing structure, catfishproducts, post-harvest technology as wellas the role <strong>of</strong> other sectors involved inthe industry. In addition, past and currentresearch in the area <strong>of</strong> biology, breedingand genetics, seed production, feeds andnutrition, and production managementwere discussed and given in the countryreports. Representatives <strong>of</strong> each countryalso presented gaps, constraints, issuesand research priorities that, in their view,needed addressing.DISCUSSION FROM KEYNOTESPEAKERSThe seven keynote speakers addressed awhole range <strong>of</strong> issues needed to developa genetic improvement program for Clariasgariepinus. Highlighted areas included thetaxonomy <strong>of</strong> the species, its distribution inAfrica, biological characteristics, growthperformance, reproductive management,culture systems, feed and nutrition, geneticprinciples for the design <strong>of</strong> breedingprograms, dissemination strategies <strong>of</strong>improved fish, tagging, rearing and breedingmethods, as well as potential applications <strong>of</strong>new technologies to maximize the efficiency<strong>of</strong> the breeding program and the economicbenefits contributed to the nationaleconomies <strong>of</strong> African countries.PRIORITY AREAS FOR FUTURERESEARCH AND TRAININGBased on the gaps, issues and constraintsidentified during the workshop, and onrecommendations emanating from thecountry reports, the priority areas for futureresearch and training were as follows:• Development <strong>of</strong> a genetically improvedstrain <strong>of</strong> C. gariepinus adapted to a widerange <strong>of</strong> production environments inAfrica;• Construction or expansion <strong>of</strong> the existingnational and regional networks <strong>of</strong>hatcheries to supply an adequate quantity<strong>of</strong> good-quality seed to farmers;• Formulation <strong>of</strong> optimal low-cost dietsbased on local feedstuffs and resourcesor agricultural by-products;• Establishment <strong>of</strong> training programs atboth international and regional levels inorder to enhance human and institutionalcapacity needed to undertake the geneticimprovement <strong>of</strong> catfish;• Development <strong>of</strong> appropriate socioeconomicpolicies to promote aquacultureand catfish production;• Development <strong>of</strong> a network <strong>of</strong> scientistsand practitioners involved with catfishproduction and management.

4 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSOBJECTIVES AND OUTPUTSThe specific objectives and the achievedoutputs <strong>of</strong> the workshop are summarized inTable 1.CLOSING REMARKSThe workshop was <strong>of</strong>ficially closed by Dr.Raul Ponzoni <strong>of</strong> the WorldFish Center. Dr.Ponzoni summarized the key achievementsand highlighted the progress made duringthe five-day workshop. He expressed hissincere thanks to all participants for theirtime, participation and contributions, andacknowledged the support <strong>of</strong> the Councilfor Scientific and Industrial Research (CSIR)<strong>of</strong> Ghana, and particularly the staff <strong>of</strong> theWater Research Institute (WRI) for theirpreparation, organization, warm welcomeand hospitality throughout the workshop.Dr. Ponzoni reiterated that the WorldFishCenter would make every effort to promotethe application <strong>of</strong> the findings <strong>of</strong> themeeting and to assist in seeking meansto pursue the concept note proposal andthe recommendations <strong>of</strong> the workshop;however, he emphasized that this was ashared responsibility <strong>of</strong> all countries involvedin future programs.Dr. Felix Attipoe from the Water ResearchInstitute (WRI) thanked the WorldFish Centerfor their dedication and efforts to make theworkshop successful. He also commentedTable 1: The workshop objectives and outputsObjectivesOutputs1 To review the state <strong>of</strong> catfish • Overview <strong>of</strong> current state and trends <strong>of</strong> catfish productionproduction and research inin African countriesAfrican countries• Overview <strong>of</strong> research undertaken in the areas <strong>of</strong> biology, breedingand genetics, nutrition and culture management2 To identify gaps, constraints and • Lack <strong>of</strong> improved strains adapted to existing farming environmentsissues in catfish productionin Africa• Poor or non-existent network <strong>of</strong> hatcheries to multiply or producegood quality seed and brood stock to supply farmers and producers• Production <strong>of</strong> low-cost diets based on local feedstuffs andagricultural resources• Socioeconomic policies to promote aquaculture and catfish3 To understand the biology, genetic • Information on taxonomy, distribution, growth characteristicsdiversity, production and<strong>of</strong> C. gariepinus relative to other African catfishreproduction, feeds and nutrition, • Technical aspects <strong>of</strong> catfish production and reproduction in thegenetic principles, practical aspects context <strong>of</strong> African countries<strong>of</strong> breeding programs, and prospects • Feeding and nutrient requirement <strong>of</strong> African catfish as a basisfor future genetic improvement <strong>of</strong> the formulation <strong>of</strong> balanced diets• Principles for the design <strong>of</strong> a breeding program and essentialpre-requisites for effective dissemination <strong>of</strong> improved fish to farmers• Practical aspects <strong>of</strong> an on-going breeding program <strong>of</strong> C. gariepinus,including control <strong>of</strong> reproduction, methods <strong>of</strong> individual identification,rearing and tagging• Potential application <strong>of</strong> molecular information and reproductivetechnologies in practical breeding programs4 To identify future priorities for • Establishment <strong>of</strong> the physical infrastructure needed to undertakeresearch and training in order to selective breeding <strong>of</strong> catfishenhance local capacity in• Conducting regional training courses to address human resourceaquaculture and catfish production needs in genetics and brood stock management• Genetic characterization and conservation <strong>of</strong> important populations<strong>of</strong> C. gariepinus• Initiation <strong>of</strong> genetic improvement programs in African catfishincluding the foundation <strong>of</strong> base populations, choice <strong>of</strong> breedingtechnology, implementation <strong>of</strong> the selection program• Development <strong>of</strong> public-private partnership (PPP) training programsto improve private sector hatchery capacity in brood stock andseed production• Strategies for effective dissemination <strong>of</strong> improved seed including aregional producers symposium5 To develop a concept note as a • A synthesized outline <strong>of</strong> the future project with clear objectives,basis for future proposal development justification and outputs, methodologies and activities, anticipatedbudgets and potential impacts (Annex F)

INTRODUCTION 5on the importance <strong>of</strong> setting up a geneticimprovement program for African catfish inthe region, and the need to establish closecooperation and a working network in thearea <strong>of</strong> aquaculture as a whole. He alsoexpressed that he had high expectationsafter this workshop, and that he hoped thatthe workshop recommendations wouldsoon materialize.On behalf <strong>of</strong> the participants, Mr. SethAgyakwah expressed gratitude to theorganizers <strong>of</strong> the meeting. He personallyappreciated the workshop which gave himand the participants a good insight and aconsiderable amount <strong>of</strong> knowledge aboutvarious technical aspects <strong>of</strong> African catfishproduction. He thought that the workshopwas a great opportunity to exchangeexperience and develop ideas for futurebreeding programs in African catfish.Mr. Seth Agyakwah also stressed theparticipants’ interest in and need for trainingin the area <strong>of</strong> quantitative genetics appliedto catfish improvement.The meeting was <strong>of</strong>ficially concluded at 5:00p.m., Friday, 9 November 2007.

6 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSCOUNTRY CASE STUDY: CATFISH INDUSTRY IN CAMEROONDavid Nguenga (1) , Victor Pouomogne (1) and Randall E. Brummett (2)(1)IRAD, BP 255, Foumban, Cameroon(2)The WorldFish Center, BP 2008, Yaoundé, CameroonABSTRACTDespite the long history <strong>of</strong> fish farming inCameroon (since 1948), large private farmsremain scarce and production from smallsubsistence units is low and does notcontribute significantly to national fisheryproduction. Since the independence <strong>of</strong>Cameroon, development <strong>of</strong> the aquaculturesector has been largely driven by internationaldonor support. Little attention has beenpaid by the government and there has beenno master plan for aquaculture developmentwith clear and achievable targets. However,Cameroon’s poor rural populations rely onfish as their main source <strong>of</strong> animal protein. Tosatisfy the high demand for fish, Cameroonimported over 130,000 tonnes <strong>of</strong> frozen fishin 2006, which represents an importantloss in currency. Government productionstatistics are unreliable. Total fish productionfrom earthen ponds was estimated at 870tonnes in 2006, <strong>of</strong> which Clarias gariepinusrepresented nearly 38 percent.The responsibility for developing theaquaculture sector in Cameroon is vestedin the Ministry <strong>of</strong> Livestock, Fisheries andAnimal Industries (MINEPIA). Aquacultureresearch falls within the competence <strong>of</strong>the Ministry <strong>of</strong> Scientific Research andInnovation (MINRESI), more precisely inthe Institute <strong>of</strong> Agricultural Research forDevelopment (IRAD). There are 12 fishstations and 20 fish breeding centers underthe MINEPIA, but most <strong>of</strong> them are now ina state <strong>of</strong> disrepair or abandonment. Withinthe IRAD, the Foumban Fish Culture andFisheries Research Station with regional andinternational vocation has the responsibilityto carry out research activities on aquacultureand inland fisheries throughout the country.As the government stations failed toproduce catfish seed on a regular basis,fish farmers have increasingly turned toprivate seed suppliers. Wild caught seed,especially Clarias species caught in theNkam River Basin in the western and littoralprovinces <strong>of</strong> Cameroon, are an importantcomponent to be taken into accountregarding aquaculture development andthe sustainable management <strong>of</strong> the aquaticecosystem.The unit <strong>of</strong> production is exclusively earthenponds with the main cultured species(Oreochromis niloticus, Clarias gariepinusor Cyprinus carpio) either in mono- orpolyculture. Semi-extensive productionsystem is common, dominated by smallscaleponds. Indirect feeding throughcompost cribs loaded with availableorganic input (mainly grass and weeds)and kitchen refuse is the general practice.Average production is around 2,000 kg/ha/year. Farmers using balanced pellet dietsregistered up to 9,000-16,000 kg/ha/year.The quantity <strong>of</strong> fish produced is usually verylow compared to demand. In this respect,nearly all fish is sold at the pond side (farmgate) and there are no marketing problems.The lack <strong>of</strong> high quality fingerlings andfeeds, as well as the inefficiency <strong>of</strong> extensionservices has been identified as some <strong>of</strong> thefactors retarding aquaculture developmentin Cameroon. The Cameroonian StrategicFramework for Sustainable AquacultureDevelopment (also known as the LimbeDeclaration, 23-26 March 2004) hasaddressed these major constraints.Cameroon has a long history <strong>of</strong> aquaculture.The first study carefully designed on the use<strong>of</strong> the African catfish Clarias gariepinus (=Clarias lazera) for aquaculture was startedin 1974 at the National Fish Culture Centerin Foumban, Cameroon, as part <strong>of</strong> a UNDP/FAO Fish Culture Development Project.

COUNTRY CASE STUDY: CATFISH INDUSTRY IN CAMEROON 7Since 1985, research activities relatedto freshwater aquaculture have beenconducted at the Foumban Fish Culture andFisheries Research Station. Most activitiesare oriented toward optimizing the artificialpropagation <strong>of</strong> the main cultured catfish(Clarias gariepinus and Heterobranchuslongifilis), as well as domesticating newcatfish species suitable for aquaculture.There is a general lack <strong>of</strong> knowledge on thegenetic variability <strong>of</strong> the different strains <strong>of</strong>C. gariepinus farmed in different parts <strong>of</strong>Cameroon, this species being alien to theriver basins in which it is cultured. Data onthe reproductive biology and feeding habits<strong>of</strong> catfish species in the wild are also lacking.The policy environment is now supportiveand Cameroon will become an importantaquaculture producer in the near future.INTRODUCTIONThe aquaculture industry in Cameroonis essentially rural and its objectives areto increase fish supplies and providesupplementary and alternative employment,generate income, and improve the nutrition<strong>of</strong> subsistence farmers (Satia et al.1988). However, fifty-nine years after theintroduction <strong>of</strong> aquaculture in the country,it has failed to improve rural nutritional andincome standards. Its contribution to nationalfishery production remains insignificant.Cameroon, although self-sufficient in mostdomains <strong>of</strong> agro-food, has defaulted on itsprovision <strong>of</strong> fish products. Fish continuesto be the main source <strong>of</strong> protein for theCameroonian populations, especially for themost underprivileged layers (Nguenga andPouomogne 2006). The national productionis essentially assured by the country’smaritime, artisanal and industrial fishingand by continental fishing. The nationalneeds increase annually in proportion withthe population growth. The gap betweendemand and supply obliges Cameroon toimport considerable quantities <strong>of</strong> frozenfish.In 2005, nearly 49 percent <strong>of</strong> animal proteinconsumed in Cameroon, 17 kg per personannually, consisted <strong>of</strong> fish (Brummett 2007).Demand is high and continues to rise withimports passing 53,000 tonnes in 1997,63,000 tonnes in 1998, and 78,000 tonnes in1999. In 2002, Cameroon imported 182,000tonnes <strong>of</strong> fish, representing 52 percent <strong>of</strong>domestic supplies, at a total cost <strong>of</strong> nearlyUS$90 million (FAOSTAT 2004). Fish pricesremain stubbornly high at around US$3.50per kg live weight on the wholesale market.Through a series <strong>of</strong> consultations facilitatedby FAO (April 2003 and December 2004) andthe WorldFish Center (April and November2004), access to markets, availability <strong>of</strong>high quality technical backstopping andregular supply <strong>of</strong> fish fingerlings have beenrepeatedly identified as key constraintsto aquaculture growth. According to thegovernment, if these can be overcome,Cameroon has the biophysical potential(i.e. land, water and feed materials) to easilyproduce 20,000 tonnes <strong>of</strong> fish per annumthrough aquaculture, and increase thecurrent production by more than a factor <strong>of</strong>twenty.OVERVIEW OF THENATIONAL AQUACULTURESECTORHISTORICAL BACKGROUNDFish farming started in Cameroon in 1948,and in 1952 the colonial administration(England in the West adjacent to Nigeria,and France in the Eastern Cameroon) built22 aquaculture demonstration stations tostrengthen the fisheries sector. By 1960,the number <strong>of</strong> private earthen fishpondsexceeded 10,000. Soon after independencein 1960, the extension effort collapsed, andmost ponds were abandoned. During theearly 1970s a UNDP/FAO regional projectincreased the number <strong>of</strong> public aquaculturestations to 32. However, declining donorsupport and the transfer <strong>of</strong> aquaculture fromthe Forestry Department to the LivestockDepartment weakened the enthusiasm.From 1980, there was a revival in focusseddonor support for aquaculture. The USAIDdeveloped common carp farming in theWestern Highlands (1980-84), and PeaceCorps Volunteers assisted until 1998; theIDRC provided support for integrated fishcum-pig-and-chickenfarming from 1986

8 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSto 1990; the Belgian cooperation agency(General Administration for Cooperationand Development, AGCD) provided supportfor catfish seed production at the FoumbanResearch Station from 1990 to 1994;the French cooperation agency providedsupport for participatory aquaculturedevelopment in the Yaoundé region from1994 to 1997; recently, DFID (UK Departmentfor International Development) supporteda participatory aquaculture project withinthe forest benchmarks <strong>of</strong> Cameroon from2000 to 2005 (WorldFish Center 2005),and currently the French Department forForeign Affairs is supporting research in apartnership project in the seven southernprovinces (La Recherche Agronomique auCameroun, REPARAC) (Pouomogne andMikolasek 2006).Since independence, the development <strong>of</strong>the aquaculture sector in Cameroon was,therefore, largely driven by internationaldonor support. Given the stop-start, topdownnature <strong>of</strong> support, the evolution <strong>of</strong> thesector until the mid-1990s has been erraticand serrated. In 1995, after evaluating pastexperiences, the Cameroon governmentpromoted a more participatory approachsuch as those supported by the FrenchCooperation Agency and DFID projects.This has resulted in considerable changesin aquaculture practices, improved use <strong>of</strong>local knowledge and practical experienceat the farm and village levels. In addition,the revision <strong>of</strong> legislation regulating freedom<strong>of</strong> associations (1992) and increases in fishprices related to the devaluation <strong>of</strong> the CFAfranc in 1994 have created an environmentfavorable to sustainable aquaculturedevelopment (Pouomogne et al. 1998;Pouomogne 2006a). Population growth andthe concomitant increase in the demandfor animal protein have also contributedsignificantly to escalating fish prices. Asa consequence, many abandoned pondshave recently been rehabilitated, althoughthis has <strong>of</strong>ten been done without technicalinput from reliable specialized extensionservices. This positive trend is linked to thenew market environment and facilitated byrecent changes in policy.PRODUCTION TRENDSAn analysis <strong>of</strong> available data from theNational Agricultural Research and ExtensionProgram (PNVRA), the WorldFish Center, theFAO Special Program for Food Security andthe Department <strong>of</strong> Fisheries <strong>of</strong> the MINEPIArevealed that by the end <strong>of</strong> 2004 there wereapproximately 4,000 active farmers with7,000 ponds (>50% new or rebuilt since1995) with an average size <strong>of</strong> 350 m². Totalfish production from earthen ponds wasestimated at 600 tonnes, <strong>of</strong> which morethan 90 percent was produced by smallscalefarmers. Nile tilapia (Oreochromisniloticus) was the most commonly farmedspecies, followed by African catfish Clariasgariepinus. The most common practiceis polyculture <strong>of</strong> Nile tilapia, with Clariasgariepinus where possible, or with otherlocally available species such as Heterotisniloticus (“kanga”), Channa obscura (“viperfish”), Hemichromis fasciatus (“pantherfish”), common carp (Cyprinus carpio) orBarbus species (Pouomogne 2005b). Thefingerlings <strong>of</strong> the other species listed aboveare obtained mostly from the wild. Theprogress <strong>of</strong> aquaculture production from1990 to 2006 is shown in Table 1.Table 1: Aquaculture production (tonnes) in Cameroon (1990-2006)Species 1990 2000 2003 2004 2006Nile tilapia 80 180 250 350 450African catfish 6 120 180 230 330Others 20 50 70 70 90Total 106 350 500 650 870Total pond surface (ha) 160 210 220 240 245Observations FAO 1997 Personal estimation, based on actual field personalrecords after PNVRA, WorldFish, FAOestimationCameroon and some specialized NGOs(CEPID, SEAPB); Pouomogne 2006b

COUNTRY CASE STUDY: CATFISH INDUSTRY IN CAMEROON 9INDUSTRY STRUCTUREResponsibility for developing the aquaculturesector is vested in the Ministry <strong>of</strong> Livestock,Fisheries and Animal Industries (MINEPIA)through the Department <strong>of</strong> Fisheries(DIRPEC). Aquaculture research falls withinthe competence <strong>of</strong> the Ministry <strong>of</strong> ScientificResearch and Innovation (MINRESI), moreprecisely in the Institute <strong>of</strong> AgriculturalResearch for Development (IRAD).There are 12 fish stations and 20 fishbreeding centers under MINEPIA (Table2). Each station constitutes the nucleus<strong>of</strong> activities in a given area and a number<strong>of</strong> breeding centers are attached to it.The fish stations were designed with theprimary objective <strong>of</strong> producing fingerlingsto support the development and expansion<strong>of</strong> aquaculture. Of these government fishstations and breeding centers, a largenumber are now in a state <strong>of</strong> disrepair orabandonment.According to Brummett (2007) in a recentcase study reviewing fish seed supply inCameroon, although these stations arelargely dysfunctional, some <strong>of</strong> the moreimportant <strong>of</strong> them possess considerableinfrastructure and potential for contributingto aquaculture development, if eitherproperly managed or transferred to theprivate sector. These include:• Ku-Bome, 35 ponds, 5.9 ha• Bamessing, 13 ponds, 1.5 ha• Bambui-Nkwen, 22 ponds, 1.7 ha• Foumban, 53 ponds, 3.5 ha• Yaounde, 14 ponds, 2.0 ha• Ngaoundere, 24 ponds, 4.0 ha• Bertoua, 42 ponds, 12.0 ha• Garoua-Boulai, 9 ponds, 4.2 haTable 2: Public breeding centers and fish culture stations under MINEPIAProvince Division Name <strong>of</strong> breeding center (C) or station (S)Adamaoua Vina Ngaoundere (S)MbereMeiganga (C)Mayo BanyoBanyo (C)Faro and DeoTignere (C)Center Mfoundi Yaounde (S)Dja and LoboSangmelima (C)Haute SanagaNanga-Eboko (C)LekieMonatele (C)Mbam InougouBafia (C)Nyong and MfoumouAkonolinga (C)Nyong and So’oMbalmayo (C)East Lom and Djerem Bertoua (S)KadeiBatouri (C)Haut-NyongDoume (C)Haut-NyongAbong-Mbang (C)Lom and DjeremBetare-Oya (S)Lom and DjeremGaroua-Boulai (C)Far-North Mayo Tsanaga Mokolo (S)Littoral Moungo Nkongsamba (S)MoungoMelongMoungoLoumSanaga MaritimeNdomNorth-West Ngo-Ketunja Bamessing (S)MezamBambui-Nkwen (S)MomoKu-Bome (S)MomoBatibo (C)West Mifi Bafoussam (S)MenouaDschang (C)BamboutosMbouda (C)NdeBangangte (C)NounFoumban (S)South Mvila Ebolowa (S)Dja and LoboSangmelima (C)

10 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSAmong the catfish species, Clarias gariepinus,Clarias jaensis and Heterobranchus longifilisappear to be farmed the most. Clariasjaensis seeds are collected from the wild astechniques for artificial reproduction are yetto be established.As these government stations have failedto alleviate any <strong>of</strong> the main constraints onaquaculture, fish farmers have increasinglyturned to other suppliers for informationand fingerlings. Since the revision <strong>of</strong> thelaws covering the formation <strong>of</strong> farmergroups was lifted in 1990, over 90 NGOsand Common Initiative Groups dealing withagriculture and rural development, includingaquaculture, have sprung up. Many <strong>of</strong> these<strong>of</strong>fer technical advice on aquaculture, anda few have attempted to operate smallhatcheries to supply their members withseed. Unfortunately, the level <strong>of</strong> technologyused by these groups is minimal, andnone <strong>of</strong> the efforts to overcome the seedshortage have so far produced sustainableoutcomes.As a result <strong>of</strong> the failure <strong>of</strong> hatcheries tomeet the demand for fingerlings, mostfarmers buy or trade amongst themselves,or buy fingerling from fishers.The poor seed supply situation is exacerbatedby a lack <strong>of</strong> fish growers. Without a sufficientnumber <strong>of</strong> growers to buy fingerlings overthe course <strong>of</strong> a year, hatcheries cannot bepr<strong>of</strong>itable. On the other hand, if suitablefingerlings are not available when needed,producers cannot produce. Since 2002,the WorldFish Center, in conjunction withthe Government <strong>of</strong> Cameroon and a localNGO called Service d’Études et d’Appuiaux Populations à la Base (SEAPB), hasfocused attention on the linkage betweenmarkets, producers and hatcheries with theobjective <strong>of</strong> developing practical strategiesfor private-sector hatcheries, grow-outand marketing that can allow smaller-scaleproducers to participate, and possibly leadto growth <strong>of</strong> fish farming in and aroundthe urban markets <strong>of</strong> Central and WesternProvinces. At present, three private catfishhatcheries engaged in this joint project arethe main suppliers <strong>of</strong> high-quality fingerlingsin the country (Table 3).The total number <strong>of</strong> fingerlings traded isunknown, and government productionstatistics are unreliable because most fishare consumed in villages and do not reachurban markets where they might be counted.According to the WorldFish Center’s projectdatasets, approximately 15 tonnes <strong>of</strong> freshTable 3: Private catfish hatcheries known to be operating in Cameroon as <strong>of</strong> November 2005Farmer Location Species Facilities StatusNkoua, Bruno Nkoabang, Central Province Catfish Hatchery building + 7 ponds, Active9,000 m 2Diogne, Michel Batié, West Province Catfish Hatchery building + 6 ponds, Active2,400 m 2Ndoumou, Antoine Nkolmesseng, Central Province Catfish 1 pond + 8 tanks, 2,500 m 2 ActiveWouanji, Jean Bandjoun, West Province Catfish 3 ponds, 900 m 2 StartupYoudom, Bernard Batié-Nsoh, West Province Catfish 10 ponds, 5,000 m 2 StartupTamo, David Bafoussam, West Province Catfish 6 ponds, 1,200 m 2 StartupAwoa, Lucien Yemssoa, Central Province Catfish Hatchery building + 5 ponds, Startup3,200 m 2Tabi, Abodo Mbankomo, Central Province Tilapia, Hatchery building + 19 ponds, Dormantcatfish 9,500 m 2Yene, Joseph Nkoabang (Lada), Central Province Catfish 12 ponds, 360 m 2 PeriodicYong-Sulem, Steve Mbankolo, Central Province Catfish 23 ponds, 2,100 m 2 PeriodicNoupimbong, Maurice Bapi, West Province Catfish, 6 ponds, 700 m 2 PeriodictilapiaOben, Benedicta Buea, SW Province Catfish Hatchery building + 5 Periodicconcrete tanksEbanda, Jeanne Mbandoum, Central Province Tilapia 17 ponds, 7,000 m 2 Dormant(From: Brummett 2007)

COUNTRY CASE STUDY: CATFISH INDUSTRY IN CAMEROON 11catfish were traded at the urban market <strong>of</strong>Yaoundé in 2004. To produce this amount<strong>of</strong> fish, 185,000 catfish fingerlings werestocked. If these values are extrapolatedto the government estimates (2002) <strong>of</strong>114 tonnes <strong>of</strong> catfish, the total number <strong>of</strong>fingerlings stocked was on the order <strong>of</strong> 1.4million.The collection <strong>of</strong> fingerlings from the wildfor aquaculture appears to be on a smallerscale compared to fishing catfish for directhuman consumption. In 2006, about 10tonnes <strong>of</strong> catfish were harvested fromflood ponds in the Nkam River Basin. Over300,000 Clarias jaensis fingerlings werecollected and distributed for aquaculture,along with almost 50,000 Clarias gariepinus(Pouomogne 2007).In Cameroon, collecting catfish juvenilesfor culture-based aquaculture is specific tothe Nkam River Basin. Surprisingly, withinthe hundreds <strong>of</strong> rivers <strong>of</strong> the same scale inwhich Clarias spp are fished, collection <strong>of</strong>juveniles remains a marginal activity.The Foumban IRAD Specialized Stationwith regional and international vocationis responsible for carrying out researchactivities on aquaculture and inlandfisheries throughout the national territory.Research facilities such as ponds (1 ha), amodern hatchery with a flow-through anda re-circulating water system (estimatedcapacity <strong>of</strong> fry production: 2 million annually),equipment and facilities are available and,in the near future, will enable the station tosatisfy the demand <strong>of</strong> fish farmers in terms<strong>of</strong> seed <strong>of</strong> the various fish species culturedin Cameroon.PRODUCTION SYSTEMS ANDFARMING PRACTICESCameroon has a 475,000 km² surfacearea <strong>of</strong> which 63.5 percent, the so-calledBig Southern Cameroon with favorableagro-ecologic features (namely year-roundrainfall distribution), presents fair potentialfor earthen pond freshwater aquaculture.The unit <strong>of</strong> production is exclusively earthenponds with the main cultured species(Oreochromis niloticus, Clarias gariepinusor Cyprinus carpio) either in mono- orpolyculture.Use <strong>of</strong> the semi-extensive productionsystem is common, dominated by smallscaleponds. Indirect feeding throughcompost cribs loaded with availableorganic input (mainly grass and weeds)and kitchen refuse is the general practice.This is a consequence <strong>of</strong> the systematicimpoverishment <strong>of</strong> rural people due to themacro-economic policies imposed by theWorld Bank and the International MonetaryFund (IMF) from the end <strong>of</strong> the 1980s. Onaverage, the compost cribs comprise 10percent <strong>of</strong> the pond surface area. Theaverage production is around 2,000 kg/ha/yr. The most progressive farmers (about15% <strong>of</strong> the total) are concentrated mainlyaround Yaoundé (the capital city). They useadditional organic fertilizers (e.g., dry chickendroppings from commercial chicken farms)or compounded low cost pellets (presentlyavailable from the IRAD and the WorldFishCenter’s pilot feed manufacturing plants).The recent participatory approaches <strong>of</strong> theWorldFish Center and FAO have resulted inproduction levels <strong>of</strong> around 9,000 kg/ha/year. A group <strong>of</strong> wealthier farmers usingpelletized balanced diets registered upto 16,000 kg/ha/year, but for poor humancapital management reasons, the processis far from being sustainable.MARKETING SYSTEMSThe quantity <strong>of</strong> fish produced is usually verylow compared to demand. In this respect,nearly all fish are sold at the pond side (farmgate) and there are no marketing problems.For peri-urban farmers, connecting themwith fresh fish retailers revealed that fishproduced (namely tilapia, Clarias andHeterotis) from ponds near large cities couldbe sold at a higher market price than fishfrom other places. The chain <strong>of</strong> this ratherluxurious produce is thus usually very short,i.e. from the producers to the consumers,with sometimes one intermediary retailer.PROBLEMS, ISSUES ANDCONSTRAINTSAquaculture has been practiced for morethan 50 years in Cameroon, and not a singleknown self-sustaining aquaculture businesscan be inventoried in the country. The story<strong>of</strong> this activity parallels the history <strong>of</strong> the

12 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUScountry: booming from 1950 (start) to 1960(independence); decline until 1970 (moreburning preoccupations for the new state)with the start <strong>of</strong> foreign multilateral donorassistance (UNDP/FAO); then, erratic andserrated evolution in relation to sporadicexternal funding until 1990, followed, todate, by a new collapse and a long period<strong>of</strong> failure for nearly all demonstrationstations. It may be recalled that followingthe end <strong>of</strong> the 1980s crisis, the governingparadigm changed, putting a stop to the“state-does-all” attitude. Single private andcommon initiative groups were promoted,and more freedom was given to undertakethem, but with higher taxation pressures.In aquaculture research and extension,participative or partnership approacheshave been initiated. As a consequence,the net production has increased, followingincreased funding <strong>of</strong> partnership research,mainly by international donors.Based on the process just described, thefollowing guidelines may be recalled:• In the context <strong>of</strong> Cameroon, aquacultureis a tough activity, actually more difficultto master and to gain pr<strong>of</strong>it than otheractivities in the agricultural sector.• For sustainability, farmers need to gainmoney from it, and aquaculture should beconsidered as such and not continuouslymarginalized as a subsistence activity:good quality seed and feed, and capitalto acquire basic materials are necessaryto push the production above theminimum critical level.• Partnership action research involving welltrained and philosophically convincedresearchers and technicians workingwith promising farmers as a team shouldbe encouraged. In other words, onlydemand-driven research, conductedby persons humble enough and with adeep desire to learn and exchange withcommitted producers, and within anenvironment where many such producerscan be found should be funded using thescarce money available.• Special credit opportunities may then bemade available to support the startingbusiness. The government may, inaddition, maintain reference stations toconserve basic genetic material and carefor other high-cost equipment requiredto implement the business initiative andmonitor its activities.PAST AND CURRENTRESEARCH IN CATFISHFish farming started in Cameroon in 1948.The country has a long history <strong>of</strong> aquacultureresearch. It started in 1967 with the UNDP/FAO Regional Fish Culture DevelopmentProject covering four countries in CentralAfrica: Congo, Gabon, Central AfricanRepublic and Cameroon. However, most<strong>of</strong> the work undertaken has been <strong>of</strong> anempirical nature. The first study carefullydesigned was on the use <strong>of</strong> the Africancatfish, Clarias gariepinus (formerly calledClarias lazera). Aquaculture was started in1974 at the National Fish Culture Center inFoumban, Cameroon, as part <strong>of</strong> a UNDP/FAO Fish Culture Development Project(Hogendoorn 1983). Field experiments on thecontrolled propagation <strong>of</strong> C. gariepinus werecarried out. Reproduction could be inducedin small ponds using desoxycorticosteroneacetate (DOCA). In artificial reproductionexperiments, ovulation was induced withacetone-dried carp pituitary glands. Sexualproducts were obtained by stripping thefemales and dissecting the males. Artificialfertilization, incubation and hatchingwere successfully carried out. Differentmethods <strong>of</strong> producing fingerlings in earthenponds were compared. To optimize theartificial reproduction <strong>of</strong> C. gariepinus foraquaculture, experiments were carriedout on short-term sperm conservationas well as hypophysation <strong>of</strong> the femalesand determination <strong>of</strong> the correct timing <strong>of</strong>stripping with respect to water temperature.The suitability <strong>of</strong> some common, natural andartificial feedstuffs for the rearing <strong>of</strong> fry <strong>of</strong> C.gariepinus was investigated. Experimentswere also carried out to study the effect<strong>of</strong> different feeding levels and feeding

COUNTRY CASE STUDY: CATFISH INDUSTRY IN CAMEROON 13frequencies on the growth and survival<strong>of</strong> C. gariepinus fingerlings. The effects<strong>of</strong> stocking density, pond size and mixedculture with Oreochromis niloticus underextensive field conditions were investigated.Experiments were also carried out to studythe effects <strong>of</strong> body weight, temperature andfeeding level in intensive tank culture.Since 1985, research activities relatedto freshwater aquaculture have beenconducted at the Foumban Fish Cultureand Fisheries Research Station within IRAD.The activities in this domain have essentiallybeen oriented toward the optimization <strong>of</strong>the techniques <strong>of</strong> induced reproduction<strong>of</strong> Clarias gariepinus and Heterobranchuslongifilis, larval rearing in earthen ponds <strong>of</strong>C. gariepinus (Yong-Sulem et al. 2006a,b and c), valorization <strong>of</strong> agricultural byproducts,and the production <strong>of</strong> thesespecies in earthen ponds under differentfarming systems. The influence <strong>of</strong> seasonalchanges on the oocyte diameter, responsesto hormonal induction and hatching qualitywere investigated in Heterobranchuslongifilis (Nguenga 1997). The effects <strong>of</strong>storage and incubation temperature on theviability <strong>of</strong> eggs, embryos and larvae werealso studied (Nguenga et al. 2004). Althoughbasic catfish reproduction technology hasbeen well established, the larval rearingstill poses serious problems due to highmortalities in ponds caused by inappropriatestarter feeds, cannibalism and predation.Investigations are underway to solve theseproblems.PRIORITY AREAS ANDFUTURE DIRECTIONSCameroon has considerable potential foraquaculture development. The hydrographicnetwork is dense and comprises severalperennial streams and rivers. Within this vastarray <strong>of</strong> aquatic resources reside at least600 species <strong>of</strong> freshwater fish. However,only a small number <strong>of</strong> species are suitablefor aquaculture, and few have actually beenproduced commercially (Brummett 2007).Clarias gariepinus is the most farmedcatfish species in Cameroon. However, itappears that this species is alien to the riverbasins in which it is cultured, having beenintroduced by various aquaculture projects.Its native range in Cameroon encompassesthe Benue River and Lake Chad. As aconsequence, there is an urgent need forthe genetic characterization <strong>of</strong> the variousstrains. Because knowledge <strong>of</strong> the biology<strong>of</strong> natural reproduction can be helpful indeveloping successful hatchery and nurseryprocedures, investigations should be carriedout on the reproductive biology and feedinghabits <strong>of</strong> potential catfish species suitablefor aquaculture.CONCLUSIONS ANDPERSPECTIVESCameroon has the potential to becomean important aquaculture producer. Theclimate and water are good (although soilsand topography are less favorable), marketsare excellent, human technical capacityis modest, but adequate, and basicinfrastructure exists in the form <strong>of</strong> an activeresearch program and a functioning trainingcenter.In addition, the policy environment, althoughcurrently vague, is generally supportive.Three international agencies (WorldFishCenter, the French Centre de CoopérationInternationale en Recherche Agronomiquepour le Développement and FAO) arecurrently active in Cameroon’s aquacultureand are working closely with the governmentand each other to ensure that past mistakesare not repeated and best practices are putin place to ensure that future growth <strong>of</strong> thesector is sustainable.Despite the general lack <strong>of</strong> money, theGovernment <strong>of</strong> Cameroon has repeatedlyexpressed its commitment to thedevelopment <strong>of</strong> aquaculture within thecountry, and the supply <strong>of</strong> high-qualityfingerlings has been identified and clearlyenunciated as the key constraint.The new IRAD catfish fingerling andbroodstock quality assurance program is astep in the right direction and is linked toprivate sector initiatives by the StrategicFramework for Aquaculture Development.

14 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSCameroon is heading towards a resolution<strong>of</strong> its fingerling supply problem and thecreation <strong>of</strong> a robust aquaculture sector.REFERENCESBrummett, R.E. 2007. Fish seed supply case study:Cameroon. 13 p.Food and Agriculture Organization <strong>of</strong> the UnitedNations (FAO). 1997. Aquaculture productionstatistics. FAO Fisheries Circular N° 815, Rev.9.FAOSTAT. 2004. Online fi sh production statistics.http://faostat.fao.org/ Food and AgricultureOrganization <strong>of</strong> the United Nations, Rome.Hogendoorn, H. 1983. The African catfi sh (Clariaslazera C. & V., 1840) – A new species foraquaculture. Wageningen Agriculture University,Wageningen. 133 p. Ph.D. dissertation.Nguenga, D. and V. Pouomogne. 2006. Etat actuelde la recherche aquacole et halieutique auCameroun. Atelier de rapprochement Minepia-Minresi pour le développement du secteurhalieutique au Cameroun. Palais des Congrès,5-6 août 2006. 10 p.Nguenga, D. 1997. A comparison <strong>of</strong> the reproductiveperformance and aquaculture potential <strong>of</strong> twostrains <strong>of</strong> an African catfi sh, Heterobranchuslongifilis Valenciennes, 1840 (Teleostei, Clariidae)in Cameroon. Katholieke Universiteit Leuven(KUL), Belgium. 155 p. Ph.D. dissertation.Nguenga, D., G.G. Teugels, M. Legendre and F.Ollevier. 2004. The effects <strong>of</strong> storage andincubation temperature on the viability <strong>of</strong> eggs,embryos and larvae in two strains <strong>of</strong> an Africancatfi sh, Heterobranchus longifilis (Siluriformes,Clariidae). Aquaculture Research 35: 1358-1369.Nguenga, D. and V. Pouomogne. 2006. Etat actuelde la recherche aquacole et halieutique auCameroun. Atelier de rapprochement Minepia-Minresi pour le développement du secteurhalieutique au Cameroun. Palais des Congrès,5-6 août 2006. 10 p.Pouomogne, V. 2005. Mission FAO, Projet TCP-2903 Diversifi cation, volet Pisciculture: Situationdes UDs au 31 mars 2005. 11 p.Pouomogne, V. 2005. Contribution to NEPADdevelopment plan for aquaculture in Africa.Preparatory workshop for Abuja Fish for AllSummit, 26-30 June 2005, Cairo. NewPartnership for Africa (NEPAD)/WorldFish Center.10 p.Pouomogne, V. 2006. Recensement des systèmesde régulation applicable à l’activité depisciculture au Cameroun. Projet EVAD/CIRADFrance. 26 p.Pouomogne, V. 2006. Study and analysis <strong>of</strong> feedand nutrients (including fertilizers) for sustainableaquaculture development in Cameroon. FAORome technical report contribution. 31 p.Pouomogne, V. and O. Mikolasek. 2006.Construction des Innovations en Partenariat(CIP): cas de la pisciculture dans les ExploitationsFamiliales Agricoles des Hautes Terres del’Ouest et de la Plaine des Mbos. Projet derecherche soumis au Reparac. 8 p. +annexesPouomogne, V. 2007. Review on the use <strong>of</strong> wildcaught Clarias catfi sh as seed in aquaculture:Case <strong>of</strong> Santchou agro-fishers in WesternCameroon. 28 p. FAO technical report (draft).Pouomogne V, Nana J-P, Pouomegne J-B. 1998.Principes de pisciculture appliquée en milieutropical africain. Comment produire du poissonà coût modéré (des exemples du Cameroun).CEPID / Coopération Française Yaoundé. Livreparu aux Presses Universitaires d’Afrique.236 p.Satia B.P., P.N. Satia and A. Amin. 1988. Largescalereconnaissance survey <strong>of</strong> socioeconomicconditions <strong>of</strong> fish farmers and aquaculturepractices in the West and North West provinces<strong>of</strong> Cameroon, p. 64-90. In Garry M. Bernasekand Howard Powles (eds.) <strong>Proceedings</strong> <strong>of</strong> aworkshop held in Bouake, Côte d’Ivoire, 14-17November 1988.Yong-Sulem, S., L. Tchantchou, F. Nguefack andR.E. Brummett. 2006a. Advanced nursing <strong>of</strong>African catfish Clarias gariepinus (Burchell1822) fi ngerlings in earthen ponds, throughrecycling <strong>of</strong> tilapia recruits. Aquaculture 256:212-215.Yong-Sulem, S. and R.E. Brummett. 2006b.Intensity and pr<strong>of</strong>i tability <strong>of</strong> Clarias gariepinusnursing systems in periurban Yaoundé,Cameroon. Aquaculture Research 37: 601-605.Yong-Sulem, S., S. Mounchili, S. Tekeng and R.E.Brummett. 2006c. Survival <strong>of</strong> Clarias gariepinusfry in earthen ponds: Effects <strong>of</strong> composts andleaks. Aquaculture 260: 139-144.WorldFish Center. 2005. Final technical report:development <strong>of</strong> integrated agricultureaquaculturesystems for small-scale farmers inthe forest margins <strong>of</strong> Cameroon. NRE9800605/522/003, U.K. Department for InternationalDevelopment, London.

THE AFRICAN CATFISH CLARIAS GARIEPINUS: A PERSPECTIVE ON ITS ROLE AND POTENTIAL IN EGYPTIAN AQUACULTURE 15THE AFRICAN CATFISH CLARIAS GARIEPINUS: A PERSPECTIVEON ITS ROLE AND POTENTIAL IN EGYPTIAN AQUACULTUREGamal El-NaggarThe WorldFish CenterAbbassa, Abou Hammad, Sharkia, EgyptABSTRACTEgyptian aquaculture has grown rapidlyover the past fifteen years and now providesan important component <strong>of</strong> national foodsupply. Production has increased from35,000 tonnes in 1992 to 540,000 tonnesin 2005. This aquaculture productionrepresents more than 60 percent <strong>of</strong> thenational fisheries production in 2005, anincrease from just 17 percent in 1992.The main increase has come from tilapia(Oreochromis niloticus) production, makingEgypt the world’s second largest producer<strong>of</strong> tilapia.This paper analyses the conditions andimplications <strong>of</strong> this spectacular growth andthe most recent trends and challenges facingthe sector’s development and sustainability.In particular, it looks at farming systems,product range and species diversificationpotential with special reference to theAfrican catfish (Clarias gariepinus). Itplaces the industry in the context <strong>of</strong> theoverall fish supply and demand in Egypt,bearing in mind the leading role <strong>of</strong> Egyptianaquaculture as a model for the whole <strong>of</strong> theAfrican continent.INTRODUCTIONFish farming has an ancient history in Egypt,dating back to at least 2000 B.C. (as seen onthe walls <strong>of</strong> the tomb <strong>of</strong> Thebaine). “Modernaquaculture”, on the other hand, stagnatedat a relatively low production level <strong>of</strong> around55,000 tonnes per year until the 1990s. Overthe last ten years, however, production hasrisen sharply to 540,000 tonnes in 2005,contributing over 60 percent <strong>of</strong> national fishproduction (GAFRD 2006). Fish farming hasbecome an important component <strong>of</strong> theagricultural sector in Egypt and a significantsource <strong>of</strong> animal protein. Production inEgypt makes up 78 percent <strong>of</strong> the totalaquaculture production in the combinedregions <strong>of</strong> the Near East and North Africaand sub-Saharan Africa (FAO 2006).Looking at the demand side in Egypt,to maintain the current per capita fishconsumption in Egypt at the same level <strong>of</strong>around 15 kg, a total <strong>of</strong> 200,000 tonnes<strong>of</strong> fish was imported in 2005 to fill the gapbetween fish supplies and demand forlocal consumption. Thus, with an inability<strong>of</strong> the capture fisheries sector to expandsustainability beyond the current harvestlevels, the aquaculture industry at large,whether freshwater or marine aquaculture,is challenged to meet the growing demandfor fish and shellfish. Keeping in mind thecontinuing growth <strong>of</strong> the population, it isexpected that the existing gap betweenfish supply and demand will becomewider, leading to a more pressing needfor fish production from aquaculture withan expected demand volume <strong>of</strong> about 1.5million tonnes by the year 2017. To achievethis growth and move beyond currentproduction levels, the constraints currentlyfaced by the sector will, therefore, need tobe removed, and pr<strong>of</strong>it margins <strong>of</strong> farmerswill need to be maintained. New speciesor technologies may become available andcould be important over the longer term,but most <strong>of</strong> the growth and development islikely to occur through further development<strong>of</strong> existing sub-sectors.Within the freshwater sector, and assumingthe introduction <strong>of</strong> alien species remainswell regulated, the most interesting specieswould probably be the African catfish(Clarias gariepinus), with establishedhatchery capability, good performance

16 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSboth in monoculture and even more so inpolyculture with tilapia, and potential marketdevelopment opportunities.OVERVIEW OF COUNTRYPRODUCTIONValued at some LE 3.5 billion at first sale,this aquaculture production represents morethan 60 percent <strong>of</strong> the national fisheriesproduction in 2005, an increase from just 17percent in 1992 (Figure 1).This growth in aquaculture productionhas been vital in supplying the needs <strong>of</strong>Egypt’s growing population, and in helpingto maintain stable prices in the face <strong>of</strong>diminishing wild catches and increasingcompetition for global supplies. As the“Food for Man”, aquaculture will have to playan even more definitive role in meeting thedietary needs <strong>of</strong> an increasing population,while making up for the decline in naturalmarine resources.PRODUCTION SYSTEMSThe main increase in aquaculture productionhas come from tilapia (O. niloticus), makingEgypt the world’s second largest tilapiaproducer. Tilapia (mainly Oreochromisniloticus), carps (mainly common carp)and mullets (Mugilidae) are the three mainfish species contributing over 95 percent<strong>of</strong> total aquaculture production during theperiod from 1995 to 2005 (Figure 2). Theremaining 5 percent <strong>of</strong> fish production fromaquaculture came from other species suchas catfish, sea bass and sea bream, andactually very little from penaeid shrimp.The tilapia share in Egyptian aquacultureproduction has risen to more than217,000 tonnes in 2005 (40% <strong>of</strong> the totalaquaculture production) (GAFRD 2006)compared to 9,679 tonnes in 1994 (16% <strong>of</strong>total aquaculture production). On the otherhand, farm-raised catfish represented justless than 2 percent <strong>of</strong> the total aquacultureproduction in 2005, as indicated in the<strong>of</strong>ficial GAFRD statistics (Figure 2).It is worth mentioning that this is the firsttime that African catfish have a whole digitrepresentation in the Egyptian aquacultureproduction. Over 28 percent <strong>of</strong> the totalAfrican catfish production was derivedfrom aquaculture in 2005 as comparedto less than 2 percent in 2004. The basicinformation on the annual production <strong>of</strong> theAfrican catfish from different sources and itstrends and dynamics as well as the averageannual wholesale prices over the periodfrom 1995 to 2005 are shown in Table 1.Within the freshwater sector, and assumingthat the introduction <strong>of</strong> alien speciesremains well regulated, the most interestingspecies would probably be the Africancatfish (Clarias gariepinus), with establishedhatchery capability, good performance intilapia polyculture, and potential marketdevelopment opportunities. As can be seen70%60%50%47%44%47%51%54%61%40%35%30%20%17% 17% 15% 14%24%15% 18% 16%10%0%1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005Figure 1: Aquaculture production as percentage <strong>of</strong> total fish production in Egypt from 1991 to 2005(Source: GAFRD statistics 2006)

THE AFRICAN CATFISH CLARIAS GARIEPINUS: A PERSPECTIVE ON ITS ROLE AND POTENTIAL IN EGYPTIAN AQUACULTURE 17from the previous table, fish farming has notbeen a major source for the African catfishproduced in Egypt except for 2005 whenconsiderable amounts <strong>of</strong> farmed catfishwere recorded (more than 10,000 tonnes)for the first time since 1996. Prior to the year2005, most <strong>of</strong> the catfish production camefrom the country’s natural fisheries suchas the River Nile and northern and internallakes (Figure 3).A number <strong>of</strong> factors have resulted in thesubstantial increase <strong>of</strong> the farm-raisedcatfish production in Egypt including, first<strong>of</strong> all, the availability <strong>of</strong> its fingerlings. Themarket demand for the species has beenon the rise and its sale price has beenincreasing as shown in Table 1.PRODUCTION SYSTEMSSeven separate sub-sectors can bedefined, <strong>of</strong> which five represent the core<strong>of</strong> production, one is traditional and rathermarginal, and another is emergent. Tw<strong>of</strong>urther sub-sectors may emerge, but havenot been developed. Most reporting sourcesuse broadly similar definitions, basedprimarily on the physical form <strong>of</strong> production240TilapiaProduction (1000 tons)20016012080CarpMulletCatfish & other4002.0090.230.1970.17 0.654 0.7290.324 0.232 0.459Figure 2: Important species produced in fish farms from 1996 to 2005 (Source: GAFRD 2006)10.6161996 1997 1998 1999 2000 2001 2002 2003 2004 2005YearsTable 1: Total annual production (tonnes) <strong>of</strong> the African catfish Clarias gariepinus and average annualwholesale price (LE/kg) from 1995 to 2005Production yearSource 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005Lake Manzala 3844 2114 5206 2814 5893 11585 10759 8943 13548 9646 7272Lake Burulus 2270 3429 3205 2940 2315 2459 2204 1909 2067 2172 2875Lake Edku 479 528 592 687 652 501 938 937 373 56 103Lake Mariut 738 900 1094 1135 1653 2360 2398 1954 1928 1933 2094Rayan 11 15 19 25 47 115 21 26 35 34 55depressionRiver Nile and 10755 11310 12317 11613 10951 14486 23215 25439 25158 12992 13422tributariesAquaculture 2009 23 197 17 654 729 324 232 459 10180Total catfish 18097 20305 22456 19411 21528 32160 40264 39532 43341 27292 36000production(tonnes)Avg price 3.25 3.50 3.75 3.75 4.22 4.16 4.1 4.38 4.84 5.30(LE/kg)

18 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSand input intensity, in turn correlating ingeneral with specific areas and speciesgroups. The primary definitions <strong>of</strong> sectorsand their potential, with the most importantsectors shaded, are given in Table 2.For tilapia, most <strong>of</strong> the production isconcentrated in the Nile delta, close tothe Northern Lakes, with some in Fayoum.In 2004 1 , the total production in the deltawas 191,578 tonnes, approximately 96.3percent <strong>of</strong> the national total, while Fayoumaccounted for 3.3 percent, farms south <strong>of</strong>Fayoum 0.3 percent, and farms near Cairoaround 0.1 percent. In the delta area, Kafr-El Sheikh governorate produced the mosttilapia with 88,079 tonnes, followed byDamietta and Sharkia, with 36,319 tonnesand 30,186 tonnes, respectively.In 2004, most tilapia production derivedfrom earthen ponds; in private farms155,541 feddan 2 produced 173,164 tonnes.Government ponds covered 13,728 feddan,producing 3,699 tonnes <strong>of</strong> tilapia. Tilapiaproduction in earthen ponds represented89 percent <strong>of</strong> the total tilapia production,the remaining 11 percent being fromintensive production in cages and tanks.Kafr-El Sheikh produced the most tilapiausing earthen ponds, whereas Damiettaproduced the most using intensive cages.All governorates using intensive methodsproduced tilapia in cages, although Beheiraand El-Fayoum also used tanks. By 2007,only Beheira continued intensive farmingwith cages and tanks, El Fayoum with tanksand Kafr-El Sheikh with cages.Since 2004, intensive tilapia productionhas been reduced as the government hasremoved most cages following concernsabout environmental impacts andnavigational obstruction. By December2006, there were 2,702 cages 3 remainingout <strong>of</strong> the original 12,495 cages in 2004.These are in the Rosetta Nile branch afterthe last dam gate between the river and thesea, where water is brackish and is outsidethe authority <strong>of</strong> the Ministry <strong>of</strong> Irrigation.African catfish production is likely to increasein importance, particularly in polyculturewith tilapia, taking into consideration theemerging situation and challenges facing theaquaculture sector such as the fluctuating/declining sale price for tilapia, while catfishprices are on the rise (Figure 4) and emerginglegislation and regulations banning the use<strong>of</strong> sex reversed tilapia fry in aquaculture.50,00040,00030,000Total lakesRiver NileAquacultureTotal production20,00010,000101800200923197176547293242324591996 1997 1998 1999 2000 2001 2002 2003 2004 2005Figure 3: Categorized production <strong>of</strong> African catfish (tonnes) from different sources from 1996 to 20051Data obtained from the General Authority for Fisheries Resources Development (GAFRD) statistics21 feddan = 4,200 m 2 – conversions are given throughout the text although spreadsheets use SI relatedunits.3Total number <strong>of</strong> cages was 2,702, <strong>of</strong> which 2,300 were in Beheira and 402 in Kafr-El Sheikh.

THE AFRICAN CATFISH CLARIAS GARIEPINUS: A PERSPECTIVE ON ITS ROLE AND POTENTIAL IN EGYPTIAN AQUACULTURE 19Table 2: Sub-sector definitions, output (2005) and potential (most important areas shaded)Farming system/ Key features/ Species Estimatedcategory locations produced Productivity output (tonnes) Key constraintsExtensive/unfertilizedE1 Fisheries-based Fish seed Various species, Very low, Un-recorded Managementaquaculture introduced into also grass carp* unmeasuredopen water bodiesE2 Integrated Some carp seed Mainly common 8-40 17,000 t Seed;(Rice-fish) still stocked, carp, some kg/feddan possibly waterlittle data* tilapiaE3 Pond Traditional Tilapia, mullet, 200-1,000 68,400 t Water(extensive) stocked/self- African catfish kg/feddanseeded areas some carpsSemi-intensive/supplementary fedS1 Pond More developed, Tilapia and 1,500–4,000 273,500 t Water, cost-(semi-intensive) mainly tilapia some mullet kg/feddan efficient feeds,based, somequality seed,moving to I1marketsIntensive/mainly fedI1 Pond (intensive) More modern Tilapia 4,500–6,000 113,900 t Feed, water,smaller units, <strong>of</strong>ten kg/feddan markets alsobetter managedseed, diseaseHighly intensive/ completely fedH1 Integrated Developed in Tilapia 15-25 kg/m 3 2,250 t Water, disease,(intensive tank new agricultural also market,system) zones feed, seedH2 Cage culture – In January 2007 Tilapia and 10-30 kg/m 3 57,400 t Sites/waterNile branches and cage numbers silver carp access, markets,irrigation canals were 20% <strong>of</strong> (now main feed, disease,those in 2005 species) seedH3 Cage culture – Future potential Various higher 10-30 kg/m 3 NA Sites, seed, alsocoastal/marine value marine feed, diseasespeciesH4 Intensive Future potential Various higher 40-100 kg/m 3 NA Markets, energyrecycle system value species costs* Free distribution <strong>of</strong> various carp species at different times; this has influenced uptake and output; tilapia seed is alsosometimes used.1210Average catfish price (LE)Average Tilapia price (LE)Price (LE/Kg)864201996 1997 1998 1999 2000 2001 2002 2003 2004 2005YearFigure 4: Annual average sale price (LE/kg) for African catfish (Clarias gariepinus) and Nile tilapia(Oreochromis niloticus) during the period from 1996 to 2005

20 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSPolyculture <strong>of</strong> Nile tilapia with African catfishhas been shown to be technically viable ifcertain factors are considered, such asadjusting the species ratio and the stockingdensity, as well as providing high quality fishfeed according to the proper amount andtime interval.MARKETING SYSTEMSThere is little detailed information so far onthe marketing structure, preferences andsubstitutability <strong>of</strong> catfish. It appears thattraditional local and city market structuresstill represent the bulk <strong>of</strong> trading, mainlyoperating through traditional wholesalers.However, contract buying from somefish farms or producer groups is alsobeing practiced, which is consistent withaquaculture-linked market changes seen inother countries. According to Feidi (2004)a large quantity <strong>of</strong> fish is transported tothe main national market <strong>of</strong> El-Obour forauction and the fish are then distributed toall parts <strong>of</strong> Greater Cairo. Catfish seem toenjoy a better market in the rural areas <strong>of</strong>the country and an even higher demand inthe southern parts <strong>of</strong> the country (UpperEgypt) where they are sold live. The marketprice for a kilogram <strong>of</strong> fresh catfish currentlyranges from LE 5.5 to 6.5 ($1.0 to $1.3),while smoked dried ones are higher.PAST AND CURRENTRESEARCH ON CATFISHFEED AND NUTRITIONThe evolution <strong>of</strong> feed and pond fertilizationhas followed a typical path, from initial use<strong>of</strong> agricultural by-products such as wheatbran, rice bran and trash fish, <strong>of</strong>fered inits original form without any processing,together with cattle or chicken manure forpond fertilization. Most fish farmers in Egyptapply fertilizers and feeds, and the bulk <strong>of</strong>farm production uses supplementary orcomplete feeding. With positive returns tointensification using these inputs, crumbledcattle feed was then used, although itslevels <strong>of</strong> fiber and <strong>of</strong> growth inhibitors suchas gossypol (from cotton seed hulls) weretoo high. Greater attention was directed tosuitable formulations (Osman and Sadek2004), following which a modern fishfeed sector has developed. Compressed(sinking) pellets, with 25 percent crudeprotein content, comprise the bulk <strong>of</strong> fishfeeds produced. Extrusion technology formaking floating pellets was introduced in thelate 1990s. The market for extruded feedsis growing (El-Sayed 2007) with a range <strong>of</strong>different formulations <strong>of</strong> fish feed availablefor different fish species, including catfish,ranging from specialized larval feeds t<strong>of</strong>ingerlings and grow-out feeds.The overall use <strong>of</strong> feeds has been variouslyreported, from estimates <strong>of</strong> only 100,000tonnes <strong>of</strong> feed supporting a production<strong>of</strong> 450,000 tonnes <strong>of</strong> fish, to more recentand probably more supportable estimates<strong>of</strong> 250,000 tonnes <strong>of</strong> fish feed production.This accounts for about 10 percent <strong>of</strong> thetotal animal feed sector (El-Sayed 2007).According to El-Sayed (2007), most feedsare now produced commercially; farmmadefeeds are rarely used and only bysmall-scale fish farmers. They usually mixfarm-made feeds by using various energysources such as wheat bran, rice bran orground corn, with protein sources (mainlylocal fishmeal or trash fish) at a 3:1 ratio.Ingredients and inclusion levels vary locallydepending on availability and cost.A number <strong>of</strong> studies have been conductedto test different feed formulations targetingthe replacement <strong>of</strong> imported fishmeal withlocally available animal protein sources,in particular poultry by-product meal andlocally produced fishmeal both as a separatesource and as a mixture <strong>of</strong> both in theformulation. Results strongly demonstratedgood potential for using a mixture <strong>of</strong> thetwo replacing sources for the best growthperformance <strong>of</strong> African catfish reared inearthen ponds (Safwat and El-Naggar 2004;and El-Naggar and Yehia 2006).MANAGEMENT: PRODUCTIONCYCLE FROM BREEDING,NURSING, REARING TOGROWING OUTAcross Africa there is a substantial andgrowing demand for African catfish as apreferred food fish. Farming <strong>of</strong> this species

THE AFRICAN CATFISH CLARIAS GARIEPINUS: A PERSPECTIVE ON ITS ROLE AND POTENTIAL IN EGYPTIAN AQUACULTURE 21is, however, constrained by the limitedavailability <strong>of</strong> fingerlings and the dependenceon hormonal injections for spawning.To address this latter constraint, researchon non-hormonal technologies has beencarried out by the WorldFish Center since2000. This led in 2002 to the identification<strong>of</strong> a methodology that could be used byfarmers. Further refinements to this methodhave taken place during 2003–2004.In parallel with refining the technology, theCenter engaged in training activities fortechnicians and farmers’ associations on theuse <strong>of</strong> the technology in Egypt and Malawi.Training was provided either as a component<strong>of</strong> the training courses organized at Abbassaor as a special training activity for groups<strong>of</strong> farmers and technicians from Egyptianuniversities and research institutions, aswell as for technicians from the region.As a result <strong>of</strong> the well-established hatcherytechnology for pond spawning and openpond nursery systems developed for thespecies (El-Naggar et al. 2002, and 2006),fingerling availability is no longer an issue forthe species. In 2005, farmers in Egypt beganto produce and market fingerlings usingthis WorldFish-developed technology anddemand for fingerlings from other farmers isgrowing rapidly. Sales <strong>of</strong> catfish have morethan doubled in the last two years on somefarms, and specialized catfish hatcheriesare now being developed by private sectorpartners to increase production further.Polyculture <strong>of</strong> Nile tilapia with African catfishhas been shown to be technically viable ifcertain factors are considered, such asadjusting the species ratio, stocking densityand high quality fish feed with the properquantity and time interval (El-Naggar 2007).BREEDING AND GENETICSThe WorldFish Center has started a programon pedigree selection <strong>of</strong> Clarias gariepinusin 2005 to improve the performance andquality <strong>of</strong> cultured catfish.PRIORITY AREASAND LIKELY FUTUREDIRECTIONSDeveloping greater efficiency and outputthrough strategic gains in efficiency broughtabout by selected application <strong>of</strong> scienceand technology — these would apply overthe medium- and long-term, but althoughmarket forces and technical innovationwill be major enabling factors, the sector’spotential cannot be fully realized without asufficiently supportive policy backgroundand associated legal instruments and otherimplementation measures.These are some points to be considered forfuture directions:• Protocols for hatchery production <strong>of</strong> theAfrican catfish should be set out carefully,recognizing the realities and costs <strong>of</strong>doing so;• To develop and disseminate geneticallyimproved seed on a reliable and continuedbasis, an effective system will require atleast one dedicated breeding center inwhich genetic improvement is carried outand a range <strong>of</strong> seed multiplication centers(i.e. hatcheries) that make the geneticallyimproved seed available to farmers;• Efficient polycultures, optimizing waterand feed inputs, production/value outputsand environmental impacts, will becomean increasingly valuable approach tocombining better water and feedingmanagement while optimizing output;• Feeds will increasingly need to be tailoredfor different production phases andseasons, and for the extent <strong>of</strong> partial orcomplete feeding. Likewise, feeds forother species and/or for polyculturemixes should be further developed;• Feeding performance is at the heart <strong>of</strong>cost-effective production in mostaquaculture systems. With, for example,a 60 percent contribution <strong>of</strong> feed coststo typical production costs, a 10 percentdrop in feed cost per tonne <strong>of</strong> output willas a single factor deliver a 6 percent dropin the break even sales price. Dependingon demand elasticity, this alone couldsupport market expansion <strong>of</strong> 3-5 percent,while maintaining pr<strong>of</strong>itability;

22 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUS• Losses due to disease, adverse weatherand environmental conditions, and otherdisruptions should be reduced throughbetter management protocols andestablished emergency responses; and• Value-added formats need to beconsidered and developed as newmarkets open for smoked fish, eitherlocally or for re-exporting as value-addedproducts to neighboring Arab states,and consequently strengthen the sector’srole and potential for expansion.Sometimes this may simply be improvedconvenience, with improved informationand availability, and not requiringsophisticated technical responses.CONCLUSIONIn conclusion, one can say that the Egyptianaquaculture sector as a whole is one <strong>of</strong>the most important and promising sectorsfor providing a good protein source for thepeople <strong>of</strong> Egypt, thus playing an essentialrole in improving livelihoods throughfood security as well as creating newemployment opportunities and fightingpoverty. This role is expected to becomeeven more prominent and, at the sametime, there will be more challenges to keepup with its current advancement levels inlight <strong>of</strong> the growing demand as a result <strong>of</strong>the country’s increasing population and thelimitations <strong>of</strong> available resources. Africancatfish does have the potential to providea sizeable contribution to the required fishproduction from aquaculture, provided thatthe current constraints are tackled andovercome. If done appropriately, this willhelp the development process <strong>of</strong> the entireaquaculture sector, not just catfish.REFERENCESEl-Naggar, G.O. and M. Yehia. 2006. Effect <strong>of</strong>different feeds with various animal proteinsources on performance and total pondproduction, <strong>of</strong> Nile tilapia (Oreochromis niloticus)and African catfish (Clarias gariepinus) inpolyculture. In Inhouse Research Review 2006.WorldFish Center, Abbassa, Abou Hammad,Sharkia, Egypt, 21 February 2006.El-Naggar, G.O., G. John, M. Rezk, W. Elwan andM. Yehia. 2006. Effect <strong>of</strong> varying density andwater level on the spawning response <strong>of</strong> Africancatfi sh Clarias gariepinus: Implications for seedproduction. Aquaculture 261: 904-907.El-Naggar, G. 2007. Effi ciency <strong>of</strong> African catfi shClarias gariepinus in controlling unwantedreproduction <strong>of</strong> Nile tilapia Oreochromis niloticusin low input production systems. EgyptianJournal <strong>of</strong> Aquatic Biology and Fisheries 11:105-113.El-Sayed, A.-F.M. 2007. Analysis <strong>of</strong> feeds andfertilizers for sustainable aquaculturedevelopment in Egypt. In M.R. Hasan (ed.)Study and analysis <strong>of</strong> feeds and nutrients forsustainable aquaculture development. Foodand Agriculture Organization <strong>of</strong> the UnitedNations, FAO Fisheries <strong>Proceedings</strong>, Rome.Feidi, I.H. 2004. Egypt, Fish utilization, domesticmarketing and consumption supply and demandsituation. Infosamak International 2004: 8-10.Food and Agriculture Organization (FAO). 2006.State <strong>of</strong> world aquaculture. Food and AgricultureOrganization <strong>of</strong> the United Nations, Rome.General Authority for Fisheries ResourcesDevelopment (GAFRD). 2006. Fisheries StatisticsYearbook.Osman, M.F. and S.S Sadek. 2004. An overview<strong>of</strong> fi sh feed industry in Egypt: Challenges andopportunities. Paper presented at the ExpertConsultation on Fish Nutrition Research andFeed Technology in Egypt. WorldFish Center,Abbassa, Abou Hammad, Sharkia, Egypt, 2ndDecember, 2004.Safwat, A., A. Gomaah and G.O. El-Naggar. 2004,Partial replacement <strong>of</strong> fi shmeal with poultryby-product meal in practical diets <strong>of</strong> the Africancatfi sh (Clarias gariepinus) reared in earthenponds: Ecological and physiological studies.Egyptian Journal <strong>of</strong> Aquatic Biology andFisheries 8: 235-249.El-Naggar, G.O., R.E. Brummett, M. Yehia and W.Elwan. 2002. Production <strong>of</strong> African catfishClarias gariepinus fi ngerlings by stimulatingspawning <strong>of</strong> brood stock in earthen pondsthrough manipulation <strong>of</strong> water depth and/ortemperature, p. 463-471. In Proc. 6th Vet. Med.Zag. Conference, 7-9 September 2002,Hurghada, Egypt.

STATUS OF CATFISH FARMING AND RESEARCH IN GHANA 23STATUS OF CATFISH FARMING AND RESEARCH IN GHANAFelix Y. Klenam Attipoe and Seth Koranteng AgyakwahCSIR-Water Research InstituteP.O. Box AH 38, Achimota, GhanaABSTRACTA review <strong>of</strong> the catfish farming industryand research in Ghana was conducted togenerate baseline information on currentfarming practices, production volumes,marketing systems and industry structure,as well as the status <strong>of</strong> research activities onthe clariid catfishes Clarias gariepinus andHeterobranchus species. The information isexpected to contribute to national planningand development <strong>of</strong> the aquaculture industryfor enhanced fish production, improvedlivelihood opportunities and assured foodsecurity. The culture production <strong>of</strong> catfish isestimated at 10 percent <strong>of</strong> the total nationalaquaculture production that is currently950 tonnes. The clariid catfish are generallycultured in semi-intensive systems inpolyculture with tilapia (mainly O. niloticus)and in some cases with the bony tongueHeterotis niloticus by small- and mediumscalefish farmers. The number <strong>of</strong> catfishhatcheries is very limited, with an estimatedproduction capacity <strong>of</strong> 4 million fingerlingsannually. There is no breeding center orprogram for the development <strong>of</strong> improvedcatfish strains. Research on the clariidcatfish has mainly focused on the biology,reproduction and husbandry (e.g. nutrition,culture systems and hatchery management).A huge local market exists for the catfish,mainly as smoked fish, while opportunitiesabound for both fresh and smoked exportsto the European markets. Major constraintshampering the development <strong>of</strong> the catfishindustry are outlined, and priority areas andlikely future directions for accelerated growthin the aquaculture industry are suggested.INTRODUCTIONFish is the principal animal protein sourcefor Ghanaians. Over the years, fish hascontributed about 70 percent <strong>of</strong> animalprotein intake. Presently, the nationalfisheries production from both the captureand culture sectors is estimated at 391,694tonnes, out <strong>of</strong> which aquaculture contributed0.3 percent, valued at US$2.251 million(FAO 2006). National fish demand standsat 648,694 tonnes, hence a shortfall <strong>of</strong>257,000 tonnes (FAO 2006).Production <strong>of</strong> fish from commercial andartisanal fisheries has continued to declineover the last two decades due to severalfactors including over-exploitation, pollution,destruction <strong>of</strong> fish habitats, destructivefishing practices and loss <strong>of</strong> foreign fishinggrounds (Balarin 1988; Danquah et al. 1999;Ofori-Danson et al. 2001, 2002; Braimah2003), while per capita fish consumptioncontinues to increase from 22 kg/caput/year in 1997 to 28 kg/caput/year in 2002(Owusu et al. 2001; FAO 2006). The role<strong>of</strong> aquaculture to bridge the gap betweencurrent demand and national productionhas long been recognized worldwide, as ithas in Ghana (FAO 2004; Attipoe 2006).Fish farming in Ghana follows two basicsystems: monoculture and polyculture. Thetilapias (mainly Oreochromis niloticus) and thecatfish (Clarias gariepinus, Heterobranchuslongifilis and Heterobranchus isopterus) arethe main species cultured in dugouts, pens,earthen ponds and cages (Owusu-Frimponget al. 1993; Attipoe 2006).The potential <strong>of</strong> catfish in aquaculture toincrease and sustain national fish productionhas long been recognized in Africa and, forthat matter, in Ghana (De Kimpe and Micha1974; Hogendoorn 1979; Hecht 1982;Danquah et al. 2006). However, its culture isstill on a limited scale in Ghana. The ability<strong>of</strong> catfish, especially the clariid catfishClarias and Heterobranchus, to live in waterwith extremely low dissolved oxygen andhigh carbon dioxide content makes them

24 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSexcellent fish for culture. Catfish can easilybe cultured at high density and give veryhigh production per unit area. Clarias andHeterobranchus catfish are highly esteemedas a delicacy. They are commonly culturedas a “police fish” to control unwantedreproduction in tilapia ponds (Owusu-Frimpong 2006).This paper reviews the state <strong>of</strong> catfishproduction in Ghana. It highlights pastand current research efforts and examinesconstraints hampering the development <strong>of</strong>the industry. Priority areas and likely futuredirections are suggested for the development<strong>of</strong> the catfish industry in Ghana.OVERVIEW OF COUNTRYPRODUCTION OF CATFISHHISTORICAL BACKGROUND OFAQUACULTUREFish farming started in Ghana in the early1950s with the construction <strong>of</strong> fishponds,dams and reservoirs by the formerDepartment <strong>of</strong> Fisheries (now called theMinistry <strong>of</strong> Fisheries) in the Northern andUpper regions <strong>of</strong> the country. These wereto serve as hatcheries to provide fish seedto support the culture-based reservoirfishery development program <strong>of</strong> the colonialadministration and as a way <strong>of</strong> supplementingthe national demand for fish and increasinglivelihood opportunities (Balarin 1988).After independence in 1957, the nationalgovernment adopted a policy to developfish ponds within all irrigation schemes inthe country, thus state-owned irrigationfacilities were developed as far as wastechnically possible by converting 5 percent<strong>of</strong> the schemes into fish ponds (Owusu etal. 2001). A campaign by the government <strong>of</strong>Ghana in the early 1970s to raise more fishas a “backyard farming activity” led to theconstruction <strong>of</strong> several earthen fishponds inboth urban and rural areas <strong>of</strong> the country.However, most <strong>of</strong> them were abandoneddue to a number <strong>of</strong> factors including – lack <strong>of</strong>technical know-how, inadequate extensionservices, lack <strong>of</strong> fish seed to stock ponds,inadequate formulated fish feed, and lack<strong>of</strong> capital to expand farms (Owusu et al.2001).Since 1993, interest in fish culture has revivedand aquaculture is now widely practicedthroughout the country with a concentrationin three <strong>of</strong> the ten administrative regions <strong>of</strong>the country (Abban 2005). The majority <strong>of</strong>fish farmers are small-scale operators usingextensive fish farming practices. Fish areproduced mainly in earthen ponds. Overthe last four years, cage culture <strong>of</strong> tilapiahas been established in the Volta Lake by anumber <strong>of</strong> private investors. The cage farmershave adopted intensive farming practices byfeeding their fish with balanced diets thatthey either prepare themselves or buy fromthe two commercial feed companies sellingcompounded diets in the country.CATFISH PRODUCTIONFish production from aquaculture in 2004 wasestimated at 950 tonnes by the Directorate<strong>of</strong> Fisheries. Although production has notbeen separated by species, it is knownthat tilapia (mainly Oreochromis niloticus)is the dominant species and constitutesnearly 88 percent <strong>of</strong> the total aquacultureproduction (FAO 2006). Catfish is thesecond most important cultured species.Its culture constitutes about 10 percent <strong>of</strong>the total national aquaculture productionwith the remaining 2 percent consisting <strong>of</strong>other species such as Heterotis niloticus.Catfish production has generally fluctuatedbetween 95 and 200 tonnes per year withinthe last decade, with highest and lowestproductions in 1996 and 2003, respectively(Figure 1).Production (metric tons)20018016014012010080604020096 97 98 99 00 01 02 03 04YearFigure 1: Estimated production level <strong>of</strong> catfish inGhana from 1996 to 2004 (Source: Ministry <strong>of</strong>Fisheries, Ghana; estimates from FAO 2006)

STATUS OF CATFISH FARMING AND RESEARCH IN GHANA 25Accurate production figures on catfish atregional levels are not available due to poorrecord keeping by the majority <strong>of</strong> farmersand an inadequate number <strong>of</strong> governmentextension <strong>of</strong>ficers who lack the neededresources to collect reliable data in ruralareas where most <strong>of</strong> the production isundertaken. Estimated figures from fishfarmers are, therefore, lower than what isactually produced. Major concentrations<strong>of</strong> fish farms are located in the Ashanti,Western and Brong-Ahafo regions. In theCentral, Eastern and Volta regions farms areless concentrated (Figure 2). Culture basedfisheries involving polyculture <strong>of</strong> severalspecies <strong>of</strong> tilapia (predominantly O. niloticus,Sarotherodon galilaeus and Tilapia zillii),catfish, Hemichromis fasciatus, Heterotisniloticus are predominant in dugouts thatare generally located in the three northernregions, namely Upper East, Upper Westand Northern regions (Figure 2).Production figures <strong>of</strong> catfish by speciesare also not available. They were, however,bulked together from production <strong>of</strong> the twomain species C. gariepinus and H. longifilis.Both species are usually available on mostfarms and are cultured either in the samepond or in separate ponds.INDUSTRY STRUCTUREThe Ministry <strong>of</strong> Fisheries is the lead agencyvested with the administrative control <strong>of</strong>aquaculture. It is also the main institutionresponsible for planning and development inthe aquaculture sub-sector. The CSIR-WaterResearch Institute is the main institutionmandated to carry out aquaculture researchin the country.Currently, there are no breeding centersor nucleus stations dedicated solely to thedevelopment and production <strong>of</strong> improvedcatfish breeds. However, a national breedingcenter for the development and production<strong>of</strong> fast-growing O. niloticus is establishedat the CSIR-Water Research Institute’sAquaculture Research and DevelopmentCenter (ARDEC) at Akosombo. The Center,in collaboration with the WorldFish Center,has developed a fast-growing O. niloticusstrain (the Akosombo strain), which currentlygrows about 20 percent faster than the wildpopulations. More than 40 percent <strong>of</strong> fishfarmers currently use the Akosombo strainin polyculture with clariid catfish.HATCHERY OPERATIONS ANDSEED PRODUCTIONThe number <strong>of</strong> catfish hatcheries in thecountry is very limited and range from smalltomedium-scale. Presently,there are three main publicand a few private ownedhatcheries (Table 1). Priorto 2003, about 90 percent<strong>of</strong> the farmers in the catfishindustry relied heavily onfingerlings collected fromthe wild to stock their ponds.This situation resulted ingross under-stocking <strong>of</strong>the ponds, as the number<strong>of</strong> fingerlings supplied wasinadequate. The range insize <strong>of</strong> the fingerlings tostock the ponds was verywide; this led to skewed fishsizes at harvest, low survivalrates and generally reducedincome earnings.Figure 2: Distribution <strong>of</strong> major fish farms and dugouts in Ghana

26 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSAn attempt was made by the government <strong>of</strong>Ghana to address the shortfall in seed supplyto farmers by sponsoring a number <strong>of</strong> privatefish farmers on a study tour to Uganda andThailand to get first-hand information onmodern catfish production systems currentlyin operation. The outcome <strong>of</strong> the tour hasbeen a tremendous improvement in hatcheryoperation and grow-out management <strong>of</strong> thecatfish industry. Currently about 50 percent<strong>of</strong> the seed requirement is obtained fromhatcheries. The capacity for seed productionfrom existing hatcheries is estimated at 4million fingerlings per annum (Table 1).Generally, breeders for hatcheries arecollected from various streams and rivers.The practice <strong>of</strong> brood stock collection isdone throughout the year, but is optimizedduring rainy seasons when breeders are ina good condition for spawning. The averagenumber <strong>of</strong> breeders used per hatcheryannually ranges from 30 to 40 females andfrom 60 to 80 males.Over the last two years, some <strong>of</strong> thehatcheries have produced their own broodstock by selecting jumpers (shooters) fromgrow-out ponds. Occasionally, some malebreeders are collected from the wild toreplenish the breeding stock. The purpose<strong>of</strong> replenishing the male breeding stock is toreplace depleted numbers because malesare generally sacrificed for milt and theirpituitary gland during the artificial spawningprocess. This practice indirectly contributesto improving the genetic diversity and fryfitness, and reduces inbreeding.Fry production in hatcheries generallyfollows the techniques <strong>of</strong> induced spawning.Pituitary gland suspension is prepared andinjected into berried females from 10 to 15Table 1: Production scale <strong>of</strong> major clariid catfishhatcheries in GhanaScale <strong>of</strong>operation (x ‘000)Category Institution / region fingerling/monthState ARDEC (Eastern) Medium (50 – 100)owned MoFi (Ashanti) Small (< 50)KNUST (Ashanti) Small (< 50)Private Kumah (Ashanti) Medium (> 50 - 100)commercial Boanda (Ashanti) Small (< 50)farmers Kpemli (Western) Medium (> 50 - 100)Note: MoFi = Ministry <strong>of</strong> Fisheries.hours prior to stripping. Milt from malesis mixed with the eggs and activated inclean water, after which they are spreadon mosquito mesh nets and incubated inconcrete tanks with a flow-through watersystem from 18 to 30 hours. The period <strong>of</strong>hatching depends on the water temperature.Larvae are fed exclusively on either Artemianauplii or Moina after yolk re-absorption for4 days. Thereafter, the catfish larvae arefed on a combination <strong>of</strong> Artemia nauplii orMoina, and formulated diet (CP 40%) for4 days. Twelve days after hatching, thefry are exclusively fed on formulated diets(locally prepared by farmers, or producedindustrially, e.g. GAFCO and AGRICARE, orimported from Israel, i.e. Dizeng<strong>of</strong>f). Fry aretransferred into shaded outdoor concretetanks or earthen ponds for nursing. Priorto their transfer, green water is generatedby applying poultry manure. Fry are sortedevery two weeks to reduce the incidence <strong>of</strong>cannibalism. Jumpers are separated fromaverage growers using improvised graders.The survival rate <strong>of</strong> fry during the first twoweeks in a private hatchery ranges between40 percent and 60 percent, while survivalduring the nursing period, which lasts from4 to 8 weeks ranges from 20 percent to 30percent.PRODUCTION SYSTEMA survey carried out in 2003 by theDirectorate <strong>of</strong> Fisheries which covered 77out <strong>of</strong> 110 administrative districts in Ghana,identified a total <strong>of</strong> 709 small-scale fishfarmers who operated 1,380 ponds with atotal area <strong>of</strong> 112.28 hectares. Productionsystems used to rear catfish in Ghana varyfrom extensive to semi-intensive, with thelatter accounting for about 60 percent <strong>of</strong> thetotal production. Some farmers rely whollyon the natural productivity <strong>of</strong> their ponds andoccasionally throw left-over food into them,while others use single agro-industrial byproducts,such as maize bran, wheat bran,rice bran, or groundnut bran to feed thefish. About 20 percent <strong>of</strong> the fish farmers,practicing the semi-intensive system <strong>of</strong>production, feed their fish with high proteindiets purchased from commercial feedmanufacturing companies operating in thecountry. Tanks and smaller earthen ponds

STATUS OF CATFISH FARMING AND RESEARCH IN GHANA 27are used as nursery receptacles to grow thejuveniles to sizes suitable for stocking growoutponds.MARKETING SYSTEMSCatfish fingerlings are sold live at the farmgate as seed to fish farmers for stockinggrow-out ponds. Current demand for catfishseed is very high throughout the year. Thishas resulted in the seed being sold atexorbitant prices. A 10 g catfish fingerlingsells for 20 GHp 1 (US$ 0.21). Table-sizefish is either sold fresh at the farm gateor smoked and sold later. Intermediaries,usually women, may also buy the fish inbulk from the farms, smoke and retail themin major market centers. Data on quantitiesthat are sold as fresh or smoked fish arenot available. However, it is estimated thatabout 70 percent <strong>of</strong> the cultured catfish issmoked. Fresh catfish is put on ice if it hasto be transported from the farm gate to themarket center in order to be sold fresh. Freshcatfish (mean weight 500 g) sells at betweenGHC 2.50 and 3.50 (US$2.70–3.80) at thefarm gate. Some fish farmers’ associationsat Kadjebi and Tarkwa are jointly operatinga deep freezer in which they store fish,including catfish, for sale to the public. Thisprevents intermediaries from buying the fishat a cheap price. In addition, smoked catfishare occasionally exported to Nigeria and theUnited Kingdom.FEED AND NUTRITIONApproximately 90 percent <strong>of</strong> the fish farmerswho feed their fish prepare their own feedfrom agro-industrial by-products, such asmaize bran, wheat bran, rice bran, wheateyelets, groundnut bran, copra cake, soyabean and fish meal. Since 2005, one localprivate commercial feed company calledGAFCO has been selling sinking pelletfish feed to farmers. Another local privatecompany, AGRICARE Ltd., also startedproduction <strong>of</strong> sinking pellet fish feed forfarmers in October 2007. A third company,Dizeng<strong>of</strong>f Ghana Ltd., imports floatingextruded diet from Raanan Fish Feed Ltd.in Israel. The crude protein levels <strong>of</strong> theimported fish feed range from 30 percentto 40 percent and are meant for both tilapiaand catfish. This feed is in 20 kg polythenepacks and is sold at GHC 0.90/kg (US$1.00/kg). The imported diets are very expensiveand prices are beyond the reach <strong>of</strong> mostfarmers.PROBLEMS, ISSUES ORCONSTRAINTSThe problems and constraints associatedwith aquaculture development in Ghanaare principally related to three main issues:inputs, institutions and production (Abbanet al. 2006).INPUT ISSUESABSENCE OF FISH SEEDThere is an acute shortage <strong>of</strong> fish seed inGhana due to the absence <strong>of</strong> an adequatenumber <strong>of</strong> hatcheries in the country. Thismakes it difficult for most farmers to plantheir production. Culture facilities are,therefore, underutilized and programmedproduction is disrupted leading to marketingproblems. Clarias seed from the hatcheriesare not certified. Owing to the scarcity, fishfarmers rush and buy whatever is producedwithout due regard to the quality <strong>of</strong> theseed. Another problem is the location <strong>of</strong> thehatcheries in relation to the grow-out ponds.The grow-out ponds are located severalkilometers from the hatchery centers; thetransport <strong>of</strong> fingerlings to stock the pondsis very stressful and leads to a high mortalityrate. This problem needs to be solved bysetting up more public and private hatcheriesclose to grow-out facilities where modernstate-<strong>of</strong>-the-art technology is applied toensure the availability <strong>of</strong> high quality fishseed. Selective breeding methods that havebeen applied to improve the growth rate <strong>of</strong>O. niloticus through a collaborative researchprogram between the Worldfish Center andthe government <strong>of</strong> Ghana at Akosombocould be applied to catfish. This wouldprotect genetic diversity, reduce inbreedingand improve the quality <strong>of</strong> the fish seed.1The unit <strong>of</strong> currency in Ghana is the cedi (GHC or ¢) which is divided into 100 pesewas GHp).

28 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSLACK OF GOOD QUALITY FISH FEEDAs stated above, only three brands <strong>of</strong> fishfeed are currently sold on the Ghanaianmarket. Two <strong>of</strong> these are sinking dietsthat do not float. The brand imported fromRaanan Ltd. in Israel is extruded and floats.However, it is very expensive and beyond thereach <strong>of</strong> the majority <strong>of</strong> farmers. It would benecessary for the government to support thelocal commercial feed manufacturers withcredit lines to modernize their productionequipment and add pellet extruder linesto their feed manufacturing plants. Furtherresearch should be accelerated on feedformulations using local agro-industrial byproducts.A public-private partnership wouldimprove production, reduce operationalcosts and enhance fish yields.LACK OF FINANCIAL RESOURCESAquaculture is an expensive venture thatrequires the support <strong>of</strong> financial institutions.The Agriculture Development Bank(ADB) was set up by the government tosupport agricultural enterprises (includingaquaculture). However, this did notmaterialize as aquaculture was viewed asa high-risk area due to the fact that somecustomers who accessed loans failed topay back. Most farmers are, therefore,finding it difficult to access funds to improvetheir business. It would be necessary for thegovernment to revise its policy on fundingaquaculture enterprises and set up specialfunds with low interest rates to support theaquaculture sector.INSTITUTIONAL ISSUESEXTENSIONGhana lacks an effective extension system tosupport a vibrant aquaculture developmentprogram. The number <strong>of</strong> trained extensionpersonnel is grossly inadequate. A highproportion <strong>of</strong> the existing extension <strong>of</strong>ficerslack the knowledge and tools requiredto effectively transfer state-<strong>of</strong>-the-arttechnology to fish farmers. The policy <strong>of</strong>establishing a Unified Extension Systemadopted in the mid-1990s has negativelyaffected aquaculture development inthe country. Most extension <strong>of</strong>ficers donot know what to do when faced withpractical problems from fish farmers. Witha substantive Ministry <strong>of</strong> Fisheries set upin 2005, it was expected that full-timeaquaculture extension <strong>of</strong>ficers would betrained to effectively support the growingaquaculture industry.RESEARCH, EDUCATION AND TRAININGThe research institutions and universitiesmandated to carry out research onaquaculture have not been adequatelyresourced to effectively carry out theirduties over the years. Most <strong>of</strong> the fundinghas been provided by international donoragencies that sometimes pursue a programthat may not be <strong>of</strong> a priority for the nationalresearch agenda. Some critical areastherefore lack research support. Thepublic, private and donor agencies shouldwork together to support a nationallydetermined research agenda for sustainableaquaculture development. There is alsothe need to develop an appropriate andstructured educational program to train thehuman resources required to support theaquaculture sector.PARTNERSHIPSPublic sector institutional linkages (i.e.research-private; government-private,private-private) are weak. National, regionaland district fish farmers’ associations areunable to positively influence governmentpolicy on aquaculture. There is, therefore,the need to strengthen fish farmers’associations and to provide training onrelevant areas to enable them to operateeffectively for the sustained growth <strong>of</strong> theindustry in Ghana.PAST AND CURRENTRESEARCH ON CATFISHResearch work on catfish species in Ghanawas initiated during the late 1980s. Themain institutions that pioneered catfishresearch during this period were the CSIR-Water Research Institute’s AquacultureResearch and Development Center(ARDEC) based at Akosombo, and theKwame Nkrumah University <strong>of</strong> Science

STATUS OF CATFISH FARMING AND RESEARCH IN GHANA 29and Technology (KNUST) located inKumasi. Research activities on catfish havegenerally been focused on aspects relatedto biology, reproduction and husbandry(nutrition, culture systems and hatcherymanagement).Unlike the extensive breeding and geneticimprovement research program conductedon the Nile tilapia, O. niloticus, resulting inan improved strain (namely the Akosombostrain) and increased production, virtuallyno such research has been conducted onthe catfish. However, the Department <strong>of</strong>Fisheries conducted trials on the production<strong>of</strong> Heteroclarias through hybridization <strong>of</strong>Clarias gariepinus and Heterobranchuslongifilis. Heteroclarias was observed to growfaster than the pure species, but was unableto reproduce naturally in ponds (Kumah,personal com.). Further trials on productionand culture evaluation <strong>of</strong> Heteroclarias werediscontinued due to ecological concernsrelated to biodiversity conservation.CATFISH RESEARCH AT CSIR-WATER RESEARCH INSTITUTE(CSIR-WRI)Clarias gariepinus and Heterobranchuslongifilis have been the two main species <strong>of</strong>catfish under investigation at the CSIR-WRI(formerly the Institute <strong>of</strong> Aquatic Biology –IAB). Under a protocol <strong>of</strong> agreement signedbetween the International DevelopmentResearch Centre (IDRC) <strong>of</strong> Ottawa, Canadaand the government <strong>of</strong> Ghana, a study on‘Development <strong>of</strong> Improved Culture Systemsfor Increased Pond Production’ wasinitiated in 1989. This work aimed at solvingsome <strong>of</strong> the problems associated with thereproduction and husbandry <strong>of</strong> catfish atthe larval and grow-out stages (Owusu-Frimpong et al. 1990). Under this project, anoutdoor hatchery was set up for the artificialreproduction <strong>of</strong> catfish. Initial spawningtrials focused on: the application <strong>of</strong> differenttypes <strong>of</strong> hormones to induce spawning;factors affecting incubation, hatchabilityand survival <strong>of</strong> fertilized eggs in stagnantand flow-through water systems; and thegrowth and survival <strong>of</strong> fry at the nurseryand juvenile stages in tanks and in earthenponds.These initial research efforts were followedin the 1990s with on-station and on-farmstudies aimed at improving survival atthe juvenile and grow-out stages, anddevelopment <strong>of</strong> a reliable protocol forproducing juvenile catfish at the rurallevel. Between 2003 and 2006, researchwas mainly conducted at the AquacultureResearch and Development Center (ARDEC)<strong>of</strong> the CSIR-WRI. It was sponsored by theWorld Bank through the Agricultural SubsectorCapacity Building Project (AgSSIP).Under this project, activities undertakenaimed at improving the production <strong>of</strong> catfishseed, comparing yields from monocultureand polyculture systems, and controllingover-reproduction in tilapia populationsusing varying sizes and ratios <strong>of</strong> catfish.The results from these research efforts aresummarized in Table 2a.CATFISH RESEARCH AT THEUNIVERSITIESCatfish research work at the KwameNkrumah University <strong>of</strong> Science andTechnology (KNUST) was mainly conductedon Heterobranchus isopterus. The mainareas <strong>of</strong> research were varied and relatedto the biology <strong>of</strong> the species. Most <strong>of</strong> thestudies were conducted between 1991 and2003. The following were some <strong>of</strong> the areas<strong>of</strong> investigation: catfish genetics (induction<strong>of</strong> triploidy in catfish), factors affecting theviability <strong>of</strong> storing sperm (germplasm); andcatfish nutrition, such as investigating dietaryprotein and carbohydrate requirements <strong>of</strong>larvae, fry and juveniles, and examination<strong>of</strong> organoleptic properties and quality <strong>of</strong>the flesh <strong>of</strong> catfish. A summary <strong>of</strong> researchconducted at KNUST in Ghana is shown inTable 2b.PRIORITY AREASAND LIKELY FUTUREDIRECTIONSAquaculture has the potential to contributesignificantly to the economy <strong>of</strong> Ghana byproviding improved livelihood opportunitiesand as a source <strong>of</strong> income to peopleinvolved in various sectors <strong>of</strong> the industry.This potential could be enhanced through

30 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSTable 2a: Major research activities on clariid catfish species (Clarias gariepinus and Heterobranchuslongifilis) at the CSIR-Water Research Institute between 1990 and 2006Project/Year Areas <strong>of</strong> research Major results reference1990– Development <strong>of</strong> capacity to 50% success in hatching experiments resulting in IAB / IDRC1994 reproduce catfish (Clarias) hatchability <strong>of</strong> 2% to 20%. Out <strong>of</strong> the study,fry to 1, 2 and 3artificially – hypophysation,using fingerling stage (mean wt. 0.6 g) achieved 22%various types <strong>of</strong> pituitarysurvival. Low survival attributed to cannibalism,hormoneas well as frog and invertebrate predationEvaluation <strong>of</strong> Clarias and O. niloticus Production in polyculture system higher IAB / IDRC 3production in polyculture and than in monoculture systemmonoculture systemsOn-station and on-farm experiments C. gariepinus found to be less effective than IAB / IDRC 4to determine appropriate stocking P. obscura in controlling overpopulation <strong>of</strong>densities and ratios <strong>of</strong> C. gariepinus O. niloticus. Also the size and yield <strong>of</strong> O. niloticusand Parachanna obscura (Family: better with P. obscura than with C. gariepinusChannidae) both fishes used as“police fish”, in controllingoverpopulation <strong>of</strong> O. niloticus inpolyculture systemDevelopment <strong>of</strong> on-farm incubation C. gariepinus seed successfully produced in farm IAB / IDRC 5systems for production <strong>of</strong> catfish fry ponds using improvised incubators and root hairs<strong>of</strong> natural aquatic macrophytes, e.g. Pistia sp2002– Development <strong>of</strong> Clarias and Survival rates <strong>of</strong> catfish seed in earthen ponds AgSSIP /2006 Heterobranchus fish seed for higher (37.7% to 76.4%) than in concrete tanks CSIR-WRIoptimal growth and survival (0.8% to 10.4%) at stocking densities <strong>of</strong> Annual Report90 fish/m 2 . Mean weights <strong>of</strong> fry 0.182 g to 20041.725 g at 30 to 42 daysDevelopment <strong>of</strong> procedures and Protocol for production <strong>of</strong> catfish Nationaltechniques to optimize hatchery fingerlings by fish farmers for improved Agriculturalproduction <strong>of</strong> C. gariepinus and survival developed ResearchH. longifilis. Systems,Ghana 2006Determination <strong>of</strong> appropriate stocking Higher growth performance obtained for all AgSSIP Projectcombinations for efficient utilization <strong>of</strong> species in polyculture than in monoculture Report; Danquahnatural and supplemented feed in Higher yield obtained in polyculture than in et al. 2006monoculture and polyculture systems monocultureComparison <strong>of</strong> growth <strong>of</strong> Clarias and Growth performance <strong>of</strong> C. gariepinus better AgSSIP ProjectHeterobranchus in monoculture and than H. longifilis in both polyculture and Report; Danquahpolyculture systems in earthen ponds monoculture systems et al. 2006Table 2b: Research activities at KNUST on Heterobranchus isopterus from 1991 to 2003Year Areas <strong>of</strong> Research Reference1991 Induction <strong>of</strong> triploidy in catfish (Heterobranchus isopterus) by temperature Tsike 1991shock treatmentPerformance <strong>of</strong> catfish (H. isopterus) fry fed on three types <strong>of</strong> feed Bint 1991Organoleptic properties <strong>of</strong> traditionally smoked and chorkor smoked catfish Oyih 1991(H. isopterus)1992 Dietary protein requirement <strong>of</strong> the African catfish (H. isopterus) fingerlings Agbobli Jnr. 1992Effects <strong>of</strong> compounded diets containing different carbohydrate protein ratios Frempong 1992on growth and survival <strong>of</strong> the African catfish (H. isopterus)1994 Growth <strong>of</strong> H. isopterus fed on diet containing plant protein at three different Kwesie 1994;levels Owusu-Boateng 19942001 Assessment <strong>of</strong> growth and survival <strong>of</strong> H. isopterus fry Wadie 20012002– Factors affecting the mobility, viability and short-term storage <strong>of</strong> Amoo 20022003 spermatozoa <strong>of</strong> H. isopterus Asubonteng 2003

STATUS OF CATFISH FARMING AND RESEARCH IN GHANA 31increased production <strong>of</strong> the African catfishClarias gariepinus, which is second in order<strong>of</strong> importance <strong>of</strong> fish species cultured inGhana. To achieve this, it is recommendedthat the following measures should betaken:• Genetic characterization anddocumentation <strong>of</strong> the local strains <strong>of</strong>Clarias gariepinus in Ghana;• Evaluation <strong>of</strong> the performance <strong>of</strong> thelocal strains in a number <strong>of</strong> productionsystems;• Establishment <strong>of</strong> a breeding and selectionprogram to improve the growth rate <strong>of</strong>the species;• Establishment <strong>of</strong> nucleus centers andregional hatcheries for distribution <strong>of</strong>high quality catfish brood stock andfingerlings to farmers;• Development <strong>of</strong> high quality feed that willsustain the aquaculture industry andmake it viable;• Training <strong>of</strong> various levels <strong>of</strong> humanresources to sustain the industry. Thisshould include researchers, extension<strong>of</strong>ficers and fish farmers;• Strengthening <strong>of</strong> fish farmers’associations at local, district, regionaland national levels for sustainedeconomic growth; and• Provision <strong>of</strong> sustainable credit facilities t<strong>of</strong>armers to initiate and/or expandaquaculture operations.CONCLUSIONThere is a very high potential for aquacultureproduction in Ghana to rapidly expandthrough the culture <strong>of</strong> the African catfishClarias gariepinus. The climate andgeographical conditions, especially in thesouthern portions <strong>of</strong> the country, favorincreased production. The government <strong>of</strong>Ghana has taken several positive measuresto support and accelerate the growth <strong>of</strong>aquaculture through the implementation <strong>of</strong>various strategies that have been outlinedin the strategic framework for aquaculturedevelopment in the country. With carefulplanning and cooperation from all playerswithin the sector, aquaculture would be ableto contribute its quota to uplift the economythrough the alleviation <strong>of</strong> poverty andprovision <strong>of</strong> assured food security.REFERENCESAbban, E.K. 2005. Aquaculture status, constraintsand priorities for development in Ghana. In J.H.Moehl, M. Halwart and R. Brummett. Report<strong>of</strong> the FAO-Worldfish Center <strong>Workshop</strong> onSmall–scale Aquaculture in Sub-Saharan Africa:Revising the Aquaculture Target Group Paradigm.CIFA Occasional Paper No. 25, 55 p.Abban, E.K., J.H. Moehl, L.K. Awity, M. Kalende,J.K. Ofori and A. Tetebo. 2006. AquacultureStrategic Framework Ghana. Ministry <strong>of</strong>Fisheries, 31 p.Agbobli, Jr., R. 1992. Dietary protein requirements<strong>of</strong> the African catfi sh (Heterobranchus isopterus)fi ngerlings. Department <strong>of</strong> Natural Resources,University <strong>of</strong> Science and Technology, Kumasi.B.Sc. Thesis.Amoo, E. 2002. Some factors affecting the mortality,viability and short-term storage <strong>of</strong> spermatozoa<strong>of</strong> Heterobranchus isopterus. Department <strong>of</strong>Natural Resources, University <strong>of</strong> Science andTechnology, Kumasi. B.Sc. Thesis.Asubonteng, A.W. 2003. Some factors affectingmobility, viability and short-term storage <strong>of</strong>spermatozoa <strong>of</strong> Heterobranchus isopterus.Department <strong>of</strong> Natural Resources, University<strong>of</strong> Science and Technology, Kumasi. B.Sc.Thesis.Attipoe, F.Y.K. 2006. Breeding and selection forfaster growth strains <strong>of</strong> the Nile tilapia,Oreochromis niloticus in Ghana. Department<strong>of</strong> Zoology. University <strong>of</strong> Cape Coast, CapeCoast, Ghana. Ph.D. Dissertation.Balarin, J.D. 1988. National reviews for aquaculturedevelopment in Africa. FAO Fish Circ. (770.18)Food and Agriculture Organization <strong>of</strong> the UnitedNations, Rome, 121 p.Bint, Y.H. 1991. The performance <strong>of</strong> the catfi sh(Heterobranchus isopterus) fry fed on threetypes <strong>of</strong> feeds. Department <strong>of</strong> Natural Resources,University <strong>of</strong> Science and Technology, Kumasi.B.Sc. Thesis.Braimah, L.I. 2003. Fisheries Management Planfor the Volta Lake, Ghana. Report prepared forthe Department <strong>of</strong> Fisheries, Ministry <strong>of</strong> Foodand Agriculture, Ghana. 77 p.CSIR-Water Research Institute. 2004. AnnualReport.Danquah, H.R., E.K. Abban and G.G. Teugles.1999. Freshwater fi shes <strong>of</strong> Ghana: Identifi cation,distribution, ecological and economicimportance. Water Research Institute. Vol. 284,53 p.

32 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSDanquah, H.R., F. Attipoe, K. Agbogah and J.N.Padi. 2006. Polyculture <strong>of</strong> Nile tilapia Oreochromisniloticus, Clarias gariepinus, Heterobranchuslongifi lis, prawns and grey mullets. AgSSIPPolyculture Project Final Report. AgriculturalSub-sector Capacity Building Project, Ghana(AgSSIP), 15 p.De Kimpe, P. and J.C. Micha. 1974. First guidelinesfor the culture <strong>of</strong> Clarias lazera in Central Africa.Aquaculture 4: 227-248.Food and Agriculture Organization <strong>of</strong> the UnitedNations. 2004. The state <strong>of</strong> world fi sheries andaquaculture, 2004. Food and AgricultureOrganization <strong>of</strong> the United Nations (FAO), Rome,153 p.Food and Agriculture Organization <strong>of</strong> the UnitedNations. 2006. Regional Review on AquacultureDevelopment 4. Sub-Saharan Africa-2005. FAOFisheries Circular No. 1017/4. Food andAgriculture Organization <strong>of</strong> the United Nations,Rome, 96 p.Frempong, G. 1992. The effects <strong>of</strong> compoundeddiets containing different carbohydrate proteinratios on the growth and survival <strong>of</strong> Africancatfi sh (Heterobranchus isopterus). Department<strong>of</strong> Natural Resources, University <strong>of</strong> Science andTechnology, Kumasi. B.Sc. Thesis.Hecht, T. 1982. Intensive rearing <strong>of</strong> Clariasgariepinus larvae (Clariidae: Pisces). S. Afr. J.Wildl. Res., 12: 101-105.Hogendoorn, H. 1979. Controlled propagation <strong>of</strong>the African catfi sh, Clarias lazera (C. and V). I.Reproductive biology and fi eld experiments.Aquaculture 17: 323-333.Kwesie, A.K. 1994. The growth <strong>of</strong> the Africancatfi sh (Heterobranchus isopterus) fed on dietcontaining plant protein at three different levels.Department <strong>of</strong> Natural Resources, University<strong>of</strong> Science and Technology, Kumasi. B.Sc.Thesis.National Agricultural Research Systems, Ghana.2006. Agricultural Technologies (2001–2006).44 p.Ofori-Danson, P.K., G.J. de Graaf and C.J.Vanderpuye. 2002. Population parameterestimates for Chrysichthys auratus and C.nigrodigitatus (Pisces: Claroteidae) in Lake Volta,Ghana. Fisheries Research 54: 267-277.Ofori-Danson, P.K., C.J. Vanderpuye and G.J. deGraaf. 2001. Growth and mortality <strong>of</strong> the catfi sh,Hemisynodontis membranaceus (Ge<strong>of</strong>froy St.Hilaire) in the northern arm <strong>of</strong> Lake Volta <strong>of</strong>Ghana. Journal <strong>of</strong> Fisheries Management andEcology 8: 37-45.Owusu-Boateng, G. 1994. The growth <strong>of</strong> theAfrican catfi sh (Heterobranchus isopterus) fedon mixed diet containing three different proteinlevels. Department <strong>of</strong> Natural Resources,University <strong>of</strong> Science and Technology, Kumasi.B.Sc. Thesis.Owusu, B.S., L. Kuwornu and A. Lomo. 2001.Integrated irrigation – aquaculture developmentand research in Ghana, p. 37–41. In J.F. Moehl,I. Beernaerts, A.G. Coche, M. Holwart and V.O.Sagna (eds.) Proposal for an African Networkon Integrated Irrigation and Aquaculture. Accra<strong>Workshop</strong> Proc. Food and AgricultureOrganization <strong>of</strong> the United Nations, Rome,75 p.Owusu-Frimpong, M. 2006. Induced breeding <strong>of</strong>the African Catfi sh Clarias gariepinus (Burchell)in farm ponds. Journal <strong>of</strong> Ghana ScienceAssociation. Vol. 8 No. 2, Dec. 2006.Owusu-Frimpong, M.F., Y.K. Attipoe and J.N. Padi.1990, 1991, 1992, 1993, 1994. Development<strong>of</strong> improved systems for increased pondproduction. IAB/IDRC (1,2,3,4,5) Reports.International Development and Research Centre,Ottawa.Oyih, M.C. 1991. Organoleptic assessment <strong>of</strong>traditionally smoked and chorkor smoked catfi sh(Heterobranchus isopterus). Dept. NaturalResources, University <strong>of</strong> Science and Technology,Kumasi. B.Sc. Thesis.Stephens, K.B. 2001. An assessment <strong>of</strong> soya beanmeal and groundnut husk as alternative proteinsources in catfi sh (Heterobranchus isopterus)diet. Department <strong>of</strong> Natural Resources, University<strong>of</strong> Science and Technology, Kumasi. B.Sc.Thesis.Tsika, S.A.K. 1991. Induction <strong>of</strong> triploidy in catfi sh(Heterobranchus isopterus) by temperatureshock treatment. Department <strong>of</strong> NaturalResources, University <strong>of</strong> Science and Technology,Kumasi. B.Sc. Thesis.Wadie, N.A. 2001. Assessment <strong>of</strong> growth andsurvival <strong>of</strong> H. isopterus fry. Department <strong>of</strong> NaturalResources, University <strong>of</strong> Science and Technology,Kumasi. B.Sc. Thesis.ACKNOWLEDGEMENTThe authors wish to thank the followingcatfish farmers in Ghana for providinginformation on their catfish productionand market practices: Messrs Nana SiawKumah <strong>of</strong> Kumah Farms, Antwere Boanda<strong>of</strong> Boanda Farms and John Kpemli <strong>of</strong> KpemliFarms. Field data provided by the Ministry <strong>of</strong>Fisheries (MoFi) is gratefully acknowledged.We also acknowledge permission, grantedby the Director <strong>of</strong> CSIR-Water ResearchInstitute, for use <strong>of</strong> information on catfishresearch at the Institute. Preparation <strong>of</strong> thisdocument was supported by the WorldFishCenter.

CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYA 33CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYAHarrison Charo-Karisa 1 , George O. Osure 2 and Nancy K. Gitonga 31Kenya Marine and Fisheries Research InstituteSangoro Aquaculture Research StationP.O. Box 136, Pap-Onditi, Kenya2Fisheries Department, Sagana Aquaculture Centre,P.O. Box 26, Sagana, Kenya3Fish Africa, P.O. Box 64358, Nairobi, KenyaABSTRACTThis paper reviews the history <strong>of</strong> aquacultureresearch and development in Kenya withreference to the African catfish (Clariasgariepinus). The authors discuss the status<strong>of</strong> farmed catfish production in Kenya andmarket trends, as well as past and presentresearch efforts. Increased demand for foodand bait for the Nile perch fishery in excess<strong>of</strong> 18 million fingerlings per annum has led toincreased interest and investment in catfishfarming in Kenya. The main constraintsto catfish farming are expensive feedsand lack <strong>of</strong> sufficient quality fish seed. Toaddress these constraints, the government<strong>of</strong> Kenya recently initiated a catfish selectivebreeding program. Funding for at least tengenerations will be required for maximalgain and success <strong>of</strong> the program. Thispaper outlines recommendations forfuture directions for the development andcontinuity <strong>of</strong> the catfish industry in Kenya.INTRODUCTIONCatfish species <strong>of</strong> the genus Clarias originatein Africa and the Middle East (Teugels 1984).The Clarias species reported in East Africa,i.e. Clarias gariepinus, Clarias liocephalus(=carsonii), Clarias werneri and Clariasalluaudi (Greenwood 1966; Teugels 1984;CLOFFA 1986), inhabit wetlands, lakes andtheir affluent rivers. Of the catfish found inKenya, the African catfish (C. gariepinus)is the most popular and relished for food.Apart from food, C. gariepinus fingerlingsare used as baitfish for the Nile perchfishery in Lake Victoria because they areable to endure extreme conditions and canwriggle on a hook for over a week. The highgrowth rate <strong>of</strong> C. gariepinus, its ability t<strong>of</strong>eed on a variety <strong>of</strong> organisms (Greenwood1966), coupled with its ability to tolerate lowoxygen, high concentrations <strong>of</strong> ammonia(NH 3) and nitrite (NO 2) in ponds and cagesrecommend it to aquaculture. C. gariepinuscan be raised in high densities resulting inhigh yields <strong>of</strong> up to 16 tonnes per hectareper year [t/ha/yr] (Okechi 2004).Aquaculture research and developmentefforts in Kenya have long concentratedon Nile tilapia (Oreochromis niloticus).However, local demand for the Africancatfish has led to increased productionfrom fish farms in several African countries.A good example is Nigeria, where clariidsincluding C. gariepinus have overtakentilapia as the major culture species (FAO2006). This indicates considerable potentialfor development <strong>of</strong> the catfish industry inother African countries like Kenya.The aim <strong>of</strong> the present paper is to reviewthe status <strong>of</strong> farmed catfish production(with emphasis on C. gariepinus) in Kenyaand market trends, as well as the presentresearch efforts and to recommend anappropriate research focus for furtherdevelopment <strong>of</strong> the industry in the country.To put the present status <strong>of</strong> catfishproduction in context, we present a shorthistory <strong>of</strong> aquaculture and the status <strong>of</strong>production in Kenya.

34 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSBACKGROUND TOAQUACULTUREGROWTH IN KENYAFish farming in Kenya started in the early1900s when colonialists stocked trout inrivers between 1910 and 1921 for sportfishing (Okemwa and Getabu 1996). Fromthe early 1920s, static water pond culturewas introduced, beginning with tilapiinesand followed by common carp and catfish.In 1948, the colonial government establishedthe Sagana and Kiganjo fish culture farmsfor the production <strong>of</strong> seed <strong>of</strong> warm- andcold-water species, respectively. Theestablishment <strong>of</strong> these stations sparked aninterest in rural fish farming. It is thoughtthat actual nationwide fish farming startedaround this time (Balarin 1985). The “eatmore fish campaign” by the FisheriesDepartment in the 1960s led to the rapidspread <strong>of</strong> rural pond fish farming to otherparts <strong>of</strong> the country. It is estimated that bythe early 1970s, the Nyanza and Westernprovinces alone had over 30,000 fishponds(Zonneveld 1983). Most <strong>of</strong> the fishponds weresmall and many were abandoned soon after(Kagai 1975). Mariculture was introduced inthe late 1970s with the establishment <strong>of</strong> theNgomeni Prawn Farm pilot project. Despitethe long history, aquaculture productionhas oscillated between 500-1,200 tonnesin the last few decades, far below capturefisheries (Figure 1). At present, the number<strong>of</strong> fish farmers is estimated at around 7,500-8,000 with over 10,000 ponds. Althoughaquaculture is yet to become commercial inKenya (Fisheries Department 2003), stronginterest by the private sector is increasingthe prospects for commercialization <strong>of</strong>aquaculture activities.Present indications are that production fromcapture fisheries is stagnating. Nevertheless,aquaculture still has to compete with capturefisheries for its market share.CATFISH PRODUCTIONAquaculture accounts for 0.6 percent<strong>of</strong> total fish production in Kenya, inlandcapture fisheries accounts for 95.4 percentand marine capture fisheries 4 percent.However, in the last few years, trade incatfish fingerlings as Nile perch bait hasbeen on the rise. Polyculture <strong>of</strong> catfish andtilapia represents 15 percent <strong>of</strong> all cultureproduction in Kenya, tilapia monoculturerepresents over 75 percent, trout takesabout 5 percent and the remaining 5 percentconsists <strong>of</strong> catfish monoculture (Ngugi andManyala 2000). Aquaculture productiondata, especially species-specific data, arenot reliable due to poor record keepingoccasioned by partial harvesting and a lack<strong>of</strong> weighing balances. Therefore, the presentdata might be greatly underestimated anddo not reflect actual production.Catfish farming has started to gainmomentum due to the high demand forNile perch long-line fishing bait. In an effortto develop catfish as bait and a food fish,several government hatcheries and farms areinvolved in catfish production in the country.Nevertheless, individual farmers, motivatedby financial benefits, are encouraged andare beginning to take up this role as well.Catfish is popular as a food fish in areasthat are not predominantly fish eating, dueto the high flesh to bone ratio. This indicatespotential for carrying out catfish farming inareas outside the Lake Victoria basin.AQUACULTURE PRODUCTIONSYSTEMSThe majority <strong>of</strong> catfish producers in Kenyaemploy earthen ponds and concrete tanks.Recirculation systems are used to incubatethe eggs to ensure that sufficient water flowsinto the egg incubation trays and aquaria. Inthe early stages prior to stocking in ponds,catfish are usually nursed in tanks. However,a few farmers grow-out their catfish t<strong>of</strong>ingerling size in tanks. At least one farm,the Baobab Farm in Mombasa, engagesin intensive grow-out <strong>of</strong> C. gariepinus andother species, such as tilapia and carps, incages, tanks and raceways, as well as inponds.EXTENSION SERVICESA multiplicity <strong>of</strong> government agenciescarries out extension work to promotefish farming in Kenya. The FisheriesDepartment, Kenya Marine and FisheriesResearch Institute (KMFRI), Moi University,

CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYA 35Lake Basin Development Authority (LBDA),Coast Development Authority, and MasenoUniversity are the key extension serviceproviders. Apart from extension services,some <strong>of</strong> these agencies also conductresearch and train farmers and extensiontechnicians. The government also promotesfish marketing by providing marketinginfrastructure. It also provides sources <strong>of</strong>seed and brood stock and organizes farmerfield days for awareness creation andcapacity building.BREEDING, MULTIPLICATIONCENTERS AND HATCHERIESSeveral government agencies producecatfish seed and brood stock. Sagana FishFarm <strong>of</strong> the Fisheries Department, Sangoroand Kegati Aquaculture Research andDevelopment Center <strong>of</strong> the Kenya Marineand Fisheries Research Institute (KMFRI),Moi University Fish Farm and Kibos FishFarm <strong>of</strong> the Lake Basin DevelopmentAuthority (LBDA) are some <strong>of</strong> the centers thatcan host breeding programs. Since 2006,two <strong>of</strong> these centers, namely the Sangoroand Kegati Aquaculture Stations, havebeen running catfish and tilapia breedingprograms with funding from the government<strong>of</strong> Kenya. These breeding programs targetfast growth and survival <strong>of</strong> C. gariepinusand Nile tilapia.Besides breeding centers, the governmenthas over 20 hatcheries or multiplicationcenters scattered across the country.These include LBDA’s five fry productioncenters in the Lake Basin at Yala, Alupe,Chwele, Borabu and Rongo. The FisheriesDepartment has several fry productioncenters, although only a few <strong>of</strong> these areoperational. The Fisheries Department’soperational multiplication centers includethe Wakhungu Fish Farm and demonstrationponds at Murang’a, Kisii, Kisumu, Lutonyi,Yala and Nyamira. The average capacity forfingerling production at these hatcheries isapproximately 140,000 fingerlings per year(Ngugi and Manyala 2000). This is equalto two million fingerlings annually fromthe government centers. Rehabilitation <strong>of</strong>these hatcheries could lead to much higherproduction <strong>of</strong> fingerlings.MARKETING SYSTEMS ANDCHALLENGESMARKETING SYSTEMSThe catfish industry and marketing structureis shown in Figure 2. Fingerlings are soldlive as baitfish or seed for stocking. Theymay be sold at the farm gate directly bythe farmer or by middlemen to other fishfarmers. Nile perch fishers buy them at fishlanding beaches. Table-size fish are soldlive at the farm gate or at market outlets. At250 1.4Production ('000s t)20015010050CaptureAquaculture1.21.00.80.60.40.201982198319841985198619871988198919801981199019911992199419951996199719981999200020011993YearFigure 1: Fish production trends in Kenya during 1980-200520022003200420050

36 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSthe market, catfish are sold as whole fish,in pieces, or semi-processed (i.e. dried,smoked, fried or filleted). Because <strong>of</strong> thedwindling capture fisheries, demand forcatfish products exceeds supply, <strong>of</strong>feringgreat market potential. Prices <strong>of</strong> table-sizecatfish are still good for catfish farmers. Apiece <strong>of</strong> catfish weighing 500 g retails foraround Kshs. 100-150 ($1.50-2.50).A recent survey in the Lake Victoria Basinindicated an overall demand <strong>of</strong> up to 50,000catfish fingerlings per day as Nile perchbait, which equates to an annual demandexceeding 18 million fingerlings (Macharia etal. 2005). At the prevailing prices <strong>of</strong> Kshs 5 –8 (or $0.07 – 0.10) per bait, this represents anNational BreedingCentersMultiplicationCenters/HatcheriesFarmer/BreederGrow-out farmersTable-size marketBait traderNile perch fishersFigure 2: Catfish industry structure in Kenyaindustry worth Kshs. 97 million ($1.4 million).Over two million hooks are used daily in theKenyan portion <strong>of</strong> Lake Victoria (FisheriesDept. 2006) indicating a much highershortfall in the supply <strong>of</strong> catfish fingerlings.Acquisition <strong>of</strong> fingerlings from the wild maydeplete wild stocks because only a limitedportion <strong>of</strong> the required catfish fingerlingsoriginates from farms. Increased production<strong>of</strong> fingerlings from aquaculture could assistin conserving the wild stocks.MARKETING CHALLENGESWithout clear information on marketdynamics, investors may get into marketingproblems. Upcoming catfish farms inKenya need either to diversify or developproduction strategies that correspond tothe dynamism <strong>of</strong> marketing systems. This isbecause the level <strong>of</strong> demand for fingerlings inKenya varies with each season and farmersshould be aware <strong>of</strong> this seasonality to avoidoverproduction. For example, the volume <strong>of</strong>fingerlings sold at the Kibos Fry ProductionCenter from 1994 to 1998 peaked with therainy seasons, i.e. March–May and August–October (Figure 3). This is the time whenfarmers require seed for stocking.Currently, there are no functioning publicprivateproduction ventures in the country.However, partnerships in which private farms<strong>of</strong>fer their facilities to research institutes anduniversities for joint research ventures arebecoming common. This may be a precursorto the establishment <strong>of</strong> meaningful publicprivatecollaborative research.8,0007,000Number <strong>of</strong> fingerlings6,0005,0004,0003,0002,0001,0000Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonthFigure 3: Volume and seasonality <strong>of</strong> catfish fingerlings sold at LBDA Kibos Fry Production Center

CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYA 37PAST AND CURRENTRESEARCH ON CATFISHDespite the slow growth <strong>of</strong> catfish farming inKenya, various research studies on catfishhave been conducted.RESEARCH ON BIOLOGY ANDECOLOGYVarious authors have described thedistribution, habitat preference, ecologyand biology <strong>of</strong> the African catfish (Clariasgariepinus Burchell). Viveen et al. (1977),Greenwood (1966) and Corbet (1960)reported that in Lake Victoria, C. gariepinusmigrates upstream during the rainy seasonsto breed, but Rinne and Wanjala (1982)indicated the existence <strong>of</strong> lake spawningpopulations. Greenwood (1966), Lung’ayia(1994) and Lowe McConnell (1975) describedthe feeding habits <strong>of</strong> C. gariepinus in Kenyanlakes and rivers.SELECTIVE BREEDING ANDGENETICSIn 2006, the government <strong>of</strong> Kenya approvedfunding for a three-year project calledSelective Fish Breeding for Quality Seed toEnhance Aquaculture Production in Kenya.The aim <strong>of</strong> the project was to provide highyielding and quality seed <strong>of</strong> C. gariepinusand O. niloticus to farmers. The projectstarted in mid-2006 with collection <strong>of</strong> broodstock from four different populations inthe Lake Victoria region. Strain evaluationand growth studies <strong>of</strong> pure strains andcrossbreeds <strong>of</strong> the different populations areongoing at the KMFRI Sangoro AquacultureResearch Station. It was the expressed hope<strong>of</strong> the government <strong>of</strong> Kenya that donors andother partners would augment its effortsin carrying out the breeding programs forcontinuity.MOLECULAR GENETICSA comprehensive study on the phylogeny<strong>of</strong> C. gariepinus populations in Kenya hasbeen done. The genetic structure at the ND5and ND6 loci <strong>of</strong> mitochondrial DNA usingRFLP–PCR indicated three phylogeneticgroups occurring between the Western Rift,Lake Baringo, the Indian Ocean and RufijiRiver (Giddelo et al. 2002). The study byGiddelo et al. (2002) indicated considerablevariation in different populations from theEast African region. Work by Teugels (1984)suggested a significant morphometricseparation between the Nile and the LakeVictoria specimens <strong>of</strong> C. gariepinus.No research has been done in Kenya onchromosome manipulation, polyploidy,gynogenesis, androgenesis, sex reversal,transgenic or genomics <strong>of</strong> C. gariepinus.FEED AND NUTRITIONHigh quality commercial formulated catfishfeeds are not available in the Kenyan market.Nutritional studies have concentrated onthe use <strong>of</strong> inexpensive locally available feedingredients for catfish due to the high cost<strong>of</strong> fishmeal. The freshwater shrimp (Caridinanilotica), blood meal, fish remains, ricebran, maize bran or wheat bran are used,depending on the region. The use <strong>of</strong> Omena,Rastrineobola argentea, is generally avoidedbecause it also serves as human food.Christensen (1981) studied genetic aspects<strong>of</strong> nutrition and concluded that males growfaster than females, implying an advantagein rearing all male C. gariepinus.FISH SURVIVAL, DISEASES ANDPARASITESIn the culture <strong>of</strong> C. gariepinus under localKenyan conditions, survival during incubationand from hatching to fingerling size is critical.Rasowo et al. (2007) evaluated the effects <strong>of</strong>formaldehyde, sodium chloride, potassiumpermanganate and hydrogen peroxidetreatments on the hatching success <strong>of</strong> C.gariepinus eggs. Based on safety concerns,ease <strong>of</strong> availability and cost, Rasowo et al.(2007) recommended a 1,000 ppm sodiumchloride treatment <strong>of</strong> catfish eggs forroutine use by rural fish farmers to improvecatfish egg hatchability. No work has beendone to increase survival at the mostcritical stage: from hatching to fingerling.Survival to fingerling stage in unprotectedponds typically ranges from 0.6 to 21 fry/m 2 (Obuya et al. 1995). A survival rate <strong>of</strong> 25percent or from 1 to 5 grams to fingerlingsize is considered good (ACRSP 2006).

38 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSAlthough not a major problem, parasiteinfestation may become common withintensification <strong>of</strong> catfish farming. Untilrecently, no work had been done on catfishparasites in Kenya. Fioravanti et al. (2007)carried out a parasitological survey tomonitor activities on the sanitary status <strong>of</strong> fishcultured in Kenya. Parasites were detectedin 93.3 percent <strong>of</strong> the C. gariepinus sampledin Kenyan dam impoundments and earthenponds. All farmed catfish tested positive forTrichodinella sp. (6.7% <strong>of</strong> the sampled fish),coccidian (46.7%), dactylogyrid (87.7%) andgyrodactylid monogeneans (6.7%).MAJOR CONSTRAINTSFACING AQUACULTUREDEVELOPMENT IN KENYAVarious constraints impede aquaculturedevelopment in Kenya. These constraintsare related to policy and socioeconomicissues.LACK OF QUALITY SEEDNo system <strong>of</strong> fish seed certification exists inthe country. Thus, the quality <strong>of</strong> fingerlingsproduced in Kenya currently is not certified.Farmers who acquire fingerlings fromrecommended production centers getdiscouraged after obtaining low yields.LACK OF STANDARDIZEDQUALITY FISH FEEDSFormulated fish feeds are not readily availablein Kenya. Although some formulations havebeen tried experimentally, using locallyavailable materials, no investor has takenup feed production due to the low level<strong>of</strong> investment in aquaculture. Affordableand cost-effective feeds are necessaryto enhance the production <strong>of</strong> farmed fish.By collaborating with the private sector,governmental institutes can upscale theproduction <strong>of</strong> fish feeds, starting up as smallscaleproduction units as the aquaculturesector grows and attracts industrial feedmanufacturers.POOR EXTENSION SERVICES ANDTECHNOLOGY TRANSFERThe country has an inadequate number <strong>of</strong>trained personnel for effective promotion<strong>of</strong> aquaculture. The training for both theexisting and potential fish farmers, especiallywomen, has not been effectively carried outdue to financial constraints and lack <strong>of</strong> anaquaculture-training facility or aquaculturecenter <strong>of</strong> excellence. This, notwithstanding,Kenya has greatly benefited from trainingprograms at its universities.LACK OF AQUACULTUREDEVELOPMENT POLICYKenya’s economy is driven mainly byagriculture and, therefore, the governmenttends to put emphasis on crops and livestockproduction. Although aquaculture is a form<strong>of</strong> agriculture, it has <strong>of</strong>ten been seen asa fisheries related activity, far removedfrom the farm. Thus, while strengtheningagricultural activities, aquaculture is usuallyleft out. A comprehensive aquaculture policyand legislation is yet to be developed.WEAK AQUACULTURERESEARCH PROGRAMSDespite its potential, aquaculture in Kenyahas not been taken as seriously as capturefisheries. Therefore, research institutionsand universities have not been adequatelyfunded to undertake any significantaquaculture research. This has restrictedaquaculture growth. Even where researchhas taken place, in most cases new researchfindings in aquaculture may not reach thefarmers in time or not at all, due to the poorlinkage between researchers and farmers.POOR DATA COLLECTIONAquaculture production data collection hasbeen poor and inefficient. The absence<strong>of</strong> record keeping <strong>of</strong> farmed fish inputs,production and sales deprives the subsector<strong>of</strong> essential data. Baseline data areneeded to ensure that interventions thatbring about any improvements in productionlevels can be recognized.

CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYA 39LOW INVESTMENTS INAQUACULTUREMany small-scale fish farmers do notconsider fish farming as an incomegenerating activity. Perhaps this is sobecause they are unaware <strong>of</strong> the economicviability <strong>of</strong> aquaculture, a perception thatstems from the past extension methodologythat emphasized aquaculture for subsistenceactivities meeting nutritional needs ratherthan for entrepreneurship. For the samereason, the private sector has not shownmuch interest in aquaculture investment,despite the favorable geographical andclimatic conditions the country enjoys. It is,therefore, necessary to carry out researchon market dynamics and potentials andrequired investment levels.PRIORITY AREAS ANDFUTURE DIRECTIONSThe catfish industry, if well nurtured, canprovide Kenya with a source <strong>of</strong> high qualityprotein, a source <strong>of</strong> income and employment.In the face <strong>of</strong> declining and unreliablewild stocks that are highly threatened byoverfishing and environmental degradation,improved aquaculture production wouldprovide an alternative source <strong>of</strong> fish to meetthe increased demands <strong>of</strong> the local andexport fisheries markets. To develop catfishculture into a viable industry, it is necessaryto improve its productivity and increase itspr<strong>of</strong>itability.One <strong>of</strong> the most important constraints isthe provision <strong>of</strong> quality fish seed. Althoughthe government <strong>of</strong> Kenya has shown itswillingness to fund selective breeding forcatfish improvement, funding is only allocatedfor the first two years. The selective breedingprogram is limited in scope because <strong>of</strong> weaklinkages among the different governmentinstitutions. Furthermore, the capacity tohandle a selective breeding program requiresstrengthening to ensure that competentpersonnel handle the improved strains at thenucleus center, multiplication centers andhatcheries. It is, therefore, necessary thatthe initial efforts by the government shouldbe augmented and the capacity <strong>of</strong> researchinstitutions strengthened. There is a needto set up and rehabilitate public hatcheries,and encourage private hatcheries withappropriate and modern technologies toensure good quality seed all the time.Kenya is currently an active member <strong>of</strong> theEast African Community (EAC), others beingUganda, Rwanda, Burundi and Tanzania.These countries share a lot in commonincluding a common EAC parliament. Byincluding an international dimension intothe management and execution <strong>of</strong> thebreeding program, the EAC countries couldbenefit as well, both in terms <strong>of</strong> expertiseand in the acquisition <strong>of</strong> improved seed. It issuggested that regional centers where theselected lines could be tested be chosen ineach <strong>of</strong> the EAC countries and that a team<strong>of</strong> scientists, extension <strong>of</strong>ficers and farmersbe trained on aspects <strong>of</strong> selective breedingand catfish husbandry.With increasing aquaculture activities, feedproduction is fast becoming an importantcommercial undertaking in its own rightand it is expected that many privateentrepreneurs will venture into the feedindustry. It is necessary that governmentagencies play a significant role as a qualitycontrol and monitoring watchdog. This willprotect the rights and interests <strong>of</strong> smallscalefarmers by ensuring that only certifiedfeeds are in the market. Provision <strong>of</strong> qualityfeeds is a sure way <strong>of</strong> ensuring that theimproved strains are able to fully realize theirpotential. Through public-private sectorpartnerships, feed mills should be set up toproduce en mass and test formulated feedsfrom research institutes.An elaborate aquaculture policy in thecountry will ensure an efficient legalframework for the dissemination <strong>of</strong> theimproved strain. Rules governing theaquaculture sector should recognize theneed to inspire private investment andincrease the rate <strong>of</strong> commercialization,while ensuring wise use <strong>of</strong> resources. Thus,incentives for aquaculture and elaboraterules and regulations on movement <strong>of</strong> strainsand prevention <strong>of</strong> escapes are required.Increasing the exchange <strong>of</strong> informationand facilitating linkages between researchand extension services in Kenya and

40 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSthroughout the East African Community(EAC), and with countries with successfulcatfish production in Africa and SoutheastAsia would be beneficial. Kenya has aninadequate number <strong>of</strong> trained personnel forthe effective promotion <strong>of</strong> aquaculture. Anaquaculture training center or aquaculturecenter <strong>of</strong> excellence should be establishedat the national or regional level to strengthenthis pool <strong>of</strong> human resources.CONCLUSIONThere is considerable potential for fishfarming in Kenya due to the country’s naturalendowment; both climatic and geographicalfeatures are conducive to aquaculture. Theslow growth <strong>of</strong> aquaculture, therefore, canbe attributed but not limited to lack <strong>of</strong> aguiding policy, perception <strong>of</strong> its benefitsas a subsistence activity as opposed to aviable commercial enterprise, ineffectiveextension strategies and technologytransfer, low government funding, andinadequate investment. In the recent past,however, fish farming, especially catfishfarming, has shown remarkable signs <strong>of</strong>growth and development, all attributed tothe realization <strong>of</strong> its pr<strong>of</strong>itability and the keeninterest <strong>of</strong> research institutions to developappropriate technologies. In particular, thecatfish selective breeding program shouldbe supported to fully realize the breedingobjectives <strong>of</strong> the country.REFERENCESAquaculture Collaborative Research SupportProgram (ACRSP). 2006. Twenty-Fourth AnnualAdministrative Report. 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CATFISH RESEARCH, PRODUCTION AND MARKETING IN KENYA 41Obuya, S., J. Ochieng and D. Campbell. 1995.Integration <strong>of</strong> chicken raising and rearing larvalClarias gariepinus in large ponds. KEN/86/027Field Document No. 3. Food and AgricultureOrganization, Rome.Okechi, J.K. 2004. Pr<strong>of</strong>i tability assessment: a casestudy <strong>of</strong> African catfi sh (Clarias gariepinus)farming in the Lake Victoria Basin, Kenya.Project Report, University <strong>of</strong> Iceland, Reykjavik,Iceland. 70 p.Okemwa, E. and A. Getabu. 1996. Fish Farmingin Kenya with Particular Reference to LakeVictoria Fisheries’. Paper Presented at theSeminar on the Management <strong>of</strong> IntegratedFreshwater Ecosystems in Tropical Areas,16-19 May 1996, Brussels.Rasowo, J., E.O. Okoth and C.C. Ngugi. 2007.Effects <strong>of</strong> formaldehyde, sodium chloride,potassium permanganate and hydrogenperoxide on hatch rate <strong>of</strong> African catfi sh Clariasgariepinus eggs. Aquaculture 269(1-4): 271-277.Rinne, J.H. and B. Wanjala. 1982. Maturity, feedingand breeding seasons <strong>of</strong> the major catfi shes(suborder: Siluroidea) in Lake Victoria, EastAfrica. Journal <strong>of</strong> Fish Biology 23: 257-363.Teugels, G.G. 1984. The nomenclature <strong>of</strong> AfricanClarias species used in aquaculture. Aquaculture38: 373-374.Teugels, G.G. 1998. Intra- and interspecificmorphometric variation in Clarias gariepinusand C. anguillaris (Siluroidei, Clariidae), p.241-247. In J.F. Agnese (ed.) Genetics andAquaculture in Africa. Offi ce de la RechercheScientifi c et Technique Outre-Mer (ORSTOM),Paris.Viveen, W.J.A.R., C.J.J. Richter, P.G.W.J. van Ood,J.A.L. Janssar and E. Auisman. 1977. Practicalmanual for the culture <strong>of</strong> the African Clariasgariepinus. Joint Publication <strong>of</strong> the DirectorGeneral International Co-operation <strong>of</strong> theMinistry <strong>of</strong> Foreign Affairs; Department <strong>of</strong> FishCulture and Fisheries <strong>of</strong> the Agricultural University<strong>of</strong> Wageningen, and Research Group forComparative Endocrinology Department <strong>of</strong>Zoology University <strong>of</strong> Utrecht, the Netherlands,78 p.Zonneveld, N. 1983. Study <strong>of</strong> the Pre-conditions<strong>of</strong> Commercial Fish Farming on the Lake VictoriaBasin, Kisumu, Kenya. Lake Basin DevelopmentAuthority (LBDA) Report. Lake BasinDevelopment Authority, 130 p.

42 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSSTATUS OF CATFISH PRODUCTION IN MALAWIBrino B. ChirwaNational Aquaculture CenterDepartment <strong>of</strong> Fisheries, P.O. Box 44, Domasi, MalawiABSTRACTMalawi capture fisheries have drasticallydeclined. The focus <strong>of</strong> the nation is now onaquaculture as a viable option to increasefish production. The commonly culturedfish, tilapia species, have been blamed forslow growth largely because <strong>of</strong> precociousbreeding habits. Introduction <strong>of</strong> fastgrowingexotic culture species has beenrestricted due to a fear <strong>of</strong> their potentialnegative impact on the biota and complexecosystems <strong>of</strong> Lake Malawi. The main focusis to screen fast-growing indigenous speciesfor aquaculture. Catfish has been identifiedas a promising fish for aquaculture because<strong>of</strong> its rapid growth rate. There are five catfishspecies found in Malawi including, Clariasgariepinus, Clarias liocephalus, Clariasngamensis, Clarias stappersii and Clariastheodore, <strong>of</strong> which Clarias gariepinus isthe most popular catfish species cultured.Catfish species are cultured in polyculturewith tilapia. The current production <strong>of</strong>cultured catfish is constrained by theinadequate supply <strong>of</strong> fingerlings. Thereare very few hatcheries producing catfishfingerlings and the survival rates in thesehatcheries are very low. Prospects forcatfish culture are encouraging, followingexisting high market demand, development<strong>of</strong> secondary industries such as themanufacturing <strong>of</strong> fish feed, and commitmentfrom the government <strong>of</strong> Malawi to promoteits development. Despite these prospects,there is an urgent need to perfect thetechnologies for nursing the hatchlings andensuring grow-out for marketing. In addition,catfish production should go in tandemwith a breeding program that will improveits performance under various cultureenvironments. Past and current researchactivities are highlighted in the paper. Priorityareas in catfish culture include promotion <strong>of</strong>its production, encouragement <strong>of</strong> privatesector involvement in fingerling productionand grow-out fish production, as well as thedevelopment <strong>of</strong> a brood stock managementand breeding program.INTRODUCTIONFish play a very important role in thesocioeconomic development <strong>of</strong> Malawi,providing much needed protein andgenerating employment for those engagedin fishing and fisheries-related activities.Fish contribute about 60–70 percent to thenation’s annual animal protein supply andprovide livelihoods to over 10 percent <strong>of</strong>the nation’s population. However, fish fromcapture fisheries have declined significantly.In light <strong>of</strong> this, the focus <strong>of</strong> attention is nowon developing aquaculture as a viable optionto increase fish production. However, theaquaculture sector in Malawi contributesabout 2 percent to national fish productionand an average productivity <strong>of</strong> 700 kg/yearis very low (Malawi Government 2005). Thecommonly cultured fish, comprising thetilapia species, have been blamed for slowgrowth largely because <strong>of</strong> their precociousbreeding habits. The introduction <strong>of</strong> exoticculture species has been restricted for fear<strong>of</strong> their accidental entry into Lake Malawiand their potential impact on the biota andcomplex ecosystems <strong>of</strong> the lake. Therefore,emphasis has turned to the development<strong>of</strong> other indigenous species with anaquaculture potential, such as Africancatfish. Clarias gariepinus was identified asthe most promising candidate for Malawianaquaculture with potential yields <strong>of</strong> morethan three times the fastest growing tilapiaspecies such as Oreochromis niloticus(Haylor 1992). Catfish species are now one<strong>of</strong> the four commonly cultured fish speciesin Malawi.

STATUS OF CATFISH PRODUCTION IN MALAWI 43OVERVIEW OF COUNTRYPRODUCTIONAquaculture production in Malawi wasestimated at 800 tonnes in 2002 and catfishcontributed 5 percent to the total production(Malawi Government 2005). Yields rangingfrom 4.47 to 4.75 tonnes per hectare wereobtained in the Northern region <strong>of</strong> Malawifrom polyculture with tilapia cultured in asemi-intensive system and fed maize branat 3 percent <strong>of</strong> body weight (Maluwa et al.1995). The national production <strong>of</strong> catfishhas been increasing, from 5 tonnes in 1996to 17 tonnes in 2003 (Table 1).CATFISH BREEDINGCurrently, there is no catfish breedingprogram in Malawi. However, propermanagement <strong>of</strong> catfish brood stock hasnow been planned to be one <strong>of</strong> the activitiesat the National Aquaculture Center. Otherstations have infrastructure that wouldfacilitate participation in a catfish breedingprogram. Such facilities are found at theBunda College Aquaculture Farm, MzuzuFish Farm and Kasinthula Fish Farm.CATFISH FINGERLINGPRODUCTION SYSTEMSThree governmental hatcheries at theNational Aquaculture Center, Mzuzu FishFarm and Kasinthula Fish Farm have thecapacity to produce catfish fingerlings.However, the number <strong>of</strong> fingerlings producedin these government hatcheries is still verylow. The major challenge at these hatcheriesis the low survival rate from the fry t<strong>of</strong>ingerling stages. A low survival rate <strong>of</strong> lessthan 10 percent has been very common. In2000, the National Aquaculture Center withtechnical support from a JICA AquacultureProject, improved the survival rate to about30 percent and produced over 20,000fingerlings in 2000 (JICA 2001) and 16,905in 2001 (ADiM 2005a). Despite technicalsupport from a number <strong>of</strong> developmentpartners to promote the development <strong>of</strong>catfish in Malawi, no significant take <strong>of</strong>foccurred in the culture <strong>of</strong> the species. Most<strong>of</strong> the efforts were limited to spawning andnot much was done to develop nursingtechnologies that would improve the survivalrate <strong>of</strong> fry. Currently, the government, withtechnical support from FAO, is supportingthe establishment <strong>of</strong> privately owned smallscalehatcheries in all three regions <strong>of</strong> thecountry.CATFISH PRODUCERSCatfish species are the fourth type preferredby fish farmers. Other popular fish includeOreochromis karongae, Oreochromisshiranus, and Tilapia rendalli. Catfishspecies are favored because <strong>of</strong> their largesize and high price (ADiM 2005a). However,information on catfish producers in Malawiis very limited. There are no reports onlarge-scale catfish producing enterprisesin Malawi. Catfish species are cultured bysmall-scale fish farmers instead. The surveyby JICA (2004) indicated that catfish werefarmed by 16 percent <strong>of</strong> the farmers in theSouthern Region <strong>of</strong> Malawi. These farmersobtain their fingerlings from governmentstations and from the wild. Sometimescatfish are unintentionally introduced intothe fish ponds.PRODUCTION SYSTEMSThe culture <strong>of</strong> catfish in Malawi has beenrestricted to extensive pond culture. Catfishspecies are mainly cultured in combinationwith Malawi’s major cultured tilapia species,namely Oreochromis shiranus, OreochromisTable 1: Estimated production levels (tonnes) and value (US$) <strong>of</strong> catfish (Clarias gariepinus) in Malawibetween 1996 and 2003YearEstimated units 1996 1997 1998 1999 2000 2001 2002 2003Production (tonnes) 5 7 10 12 15 18 10 17Value (US$, ‘000) 5.5 7.7 12.0 14. 4 18.0 18.0 11. 2 17.0Source: FAO 2003.

44 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSkarongae, Oreochromis mosambicus andTilapia rendalli. The mean body weight<strong>of</strong> Clarias gariepinus in polyculture withOreochromis karongae at the Mzuzu FishFarm was only up to 100 g after 168 days <strong>of</strong>culture when fed with maize bran (Maluŵaet al. 1995). Unpublished reports at theKasinthula Fish Farm indicate that catfishstocked at a very low density <strong>of</strong> 1,000fish/3.4 hectares attained a body weight<strong>of</strong> 1.5 kg after one year when existing inpolyculture with Oreochromis mossambicus(JICA 2004).MARKETING SYSTEMSThere is a paucity <strong>of</strong> information as far ascatfish marketing is concerned. Demand forcatfish exists in most markets, except in afew isolated communities where religiousbeliefs and attitudes restrict its consumption.Cultured catfish are usually sold fresh atthe farm gate and are purchased by localpeople living within the vicinity <strong>of</strong> the pond.The prices range from MK80 to MK100(Department <strong>of</strong> Fisheries unpublishedMonthly Reports) and vary from one placeto another. However, the price is very highif sold smoked. This implies that if catfishproduction is to be pr<strong>of</strong>itable, considerablework should be done on the marketingaspects, with an emphasis on adding valueto the product.CONSTRAINTS TO CATFISHPRODUCTIONThe limited supply <strong>of</strong> fingerlings has beena major constraint to catfish production. Asurvey conducted by ADiM (2005b) foundout that 98.6 percent <strong>of</strong> the fish farmers haddifficulties obtaining fingerlings.Appropriate feed for the culture <strong>of</strong> catfishposed another challenge to the culture<strong>of</strong> catfish in Malawi. In 2005, the cost <strong>of</strong>imported fish feeds was as high as $450per tonne (ADiM 2005b). The privatecompany, MALDECO, has installed afish feed manufacturing plant to producemainly tilapia feed. It is uncertain whetherthe production capacity <strong>of</strong> the plant wouldsatisfy the sector’s demand. Several othersmall-scale feed manufacturing units arebeing established country-wide. However,these small-scale fish feed producers lackbasic feed formulations. In addition to theavailability <strong>of</strong> appropriate fish feeds on themarket, the existing feeds are expensive.The cost <strong>of</strong> fish feed is around MK100/kgand the feed conversion ratio <strong>of</strong> aroundtwo obtained with tilapia suggests somerefinement in the feeds. In fact, fish feedcomprises about 70 percent <strong>of</strong> the totalcost <strong>of</strong> fish production.PAST AND CURRENTRESEARCH ON CATFISHBIOLOGY: ALL ASPECTSRELATED TO THE BIOLOGY OFCATFISH SPECIESEarly observations made on catfish speciesin Malawi found that the fish can attainlarge sizes with an angling record <strong>of</strong> 16.1 kg(Skelton 2001). The fish tolerate a wide range<strong>of</strong> environmental conditions, such as salinityranging from 0 to 12 ppt and temperaturesfrom 8ºC to 35ºC. Trials in Northern Malawishowed that the growth rate was notaffected even at temperatures below 21ºC(Maluŵa et al. 1995). It has wide tolerance<strong>of</strong> pH, turbidity and densities (Hecht et al.1988). In fact, some catfish species werethe last remaining in dry water bodies whenLake Chilwa dried up in 1996 (EAD 2000).For example, Clarias gariepinus is capable<strong>of</strong> breathing atmospheric air through asubranchial organ and can survive fordays in air as long as it is in a moist place.The fish can move overland under dampconditions by extending its pectoral spinesand crawling (Teugels 1995).CATFISH SPECIES, STRAINS ORPOPULATION FOUND IN MALAWICatfish species found in Malawi mainlybelong to Bagridae and Clariidae with most<strong>of</strong> the cultured catfish belonging to the latter.The external morphology <strong>of</strong> clariid catfish ischaracterized by an elongated body withlong dorsal and anal fins and the presenceor absence <strong>of</strong> an adipose fin supported byelongated neural spines (Teugels 1983).Five catfish species are widely distributed inMalawi and these include Clarias gariepinus,Clarias liocephalus, Clarias ngamensis,

STATUS OF CATFISH PRODUCTION IN MALAWI 45Clarias stappersii and Clarias theodore(Snoeks 2004). Clarias gariepinus is, however,the most popular cultured catfish species inMalawi. Other species are found in pondsin isolated cases in Northern Malawi andLower Shire River in the Southern Region <strong>of</strong>Malawi. Most <strong>of</strong> these were unintentionallyintroduced through pond inlets.BREEDING OF CATFISHBreeding <strong>of</strong> catfish is related to watertemperature. Spawning takes place attemperatures above 18ºC, usually above22ºC (Hecht et al. 1988). The size at sexualmaturity varies from 150 to 800 mm in totallength at an age <strong>of</strong> one to three years (Hechtet al. 1988). Gonadal maturation is associatedwith increasing water levels in temperaturesand the photoperiod. Spawning occursduring summer dark nights, usually after arain. Clarias produce between 50,000 and200,000 eggs (Hecht et al. 1988). In Malawi,the spawning period observed spans fromOctober to March (JICA 2001 and 2004).Since the fish do not reproduce easilyin captivity, several methods have beenapplied to help the fish to breed. Smallscalefish farmers in Malawi were ableto breed catfish using natural methods(personal observation). In addition,artificial propagation with hormones hasbeen successful at the Kasinthula FishFarm (JICA 2004). Its wide application inMalawian aquaculture has been difficultbecause <strong>of</strong> the high cost <strong>of</strong> hormones,mostly fish gonadotropins; acetone-driedcarp pituitaries sold at $279 per gram (JICA2004). The most cost-effective syntheticreleasing hormones (LHRHa and GnRHa)(Harvey and Carolsfeld 1993) might be apractical choice in Southeast Asia, butthey are not popular in Malawi because <strong>of</strong>the high cost <strong>of</strong> importing the hormones.The National Aquaculture Center utilizedpituitary glands from the common carpkept at the center (JICA 2001). Althoughthe use <strong>of</strong> the common carp pituitary incatfish breeding was cost-effective, theefficacy <strong>of</strong> the pituitaries varied for variousreasons, such as the variation in the manualremoval <strong>of</strong> the pituitary gland, improperdrying <strong>of</strong> the gland, and presence <strong>of</strong> harshclimatic conditions during storage. The JICAAquaculture Project successfully appliedand developed the procedure for spawningthe fish by using fresh male catfish pituitaryglands (JICA 2004). However, the wideapplication <strong>of</strong> the method is limited due tothe need for a large number <strong>of</strong> male catfishto be sacrificed for their pituitary glands.FEED AND NUTRITIONClarias gariepinus is omnivorous andscavenges on virtually any available organicfood source including other fish, birds, frogs,small mammals, reptiles, snails, crabs,shrimp, insects and other invertebrates, aswell as plant matter such as seeds and fruit.It is even capable <strong>of</strong> straining fine plankton(Skelton 2001). The growth performance <strong>of</strong>this catfish species is not related to warmwater as is the case with most other fishcultured in Malawi. This suggests thatthe fish is capable <strong>of</strong> growing under lowtemperature conditions as long as food isavailable. However, very little work has beendone on the chemical analysis <strong>of</strong> the locallyavailable animal feeds because <strong>of</strong> the lack<strong>of</strong> adequate and reliable laboratory facilities(Safalaoh 2002).LOCAL FEED RESOURCESFOR CATFISH FEEDPRODUCTIONAGRICULTURAL BY-PRODUCTSFOR CATFISH FEEDAgricultural by-products (from both cropsand livestock) provide potential locallyavailable sources <strong>of</strong> catfish feed. Thenational production <strong>of</strong> selected agricultureproducts whose by-products could beutilized in formulating catfish feed issummarized in Table 2. In addition, livestockand fish products are potential sources <strong>of</strong>animal protein in catfish production. Malawihas a total population <strong>of</strong> 765,000 cattle, 1.7million goats, 500,000 pigs and 120,000chickens (Government <strong>of</strong> Malawi 2004).

46 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSTable 2: Agriculture production during the2001–2002 growing seasonQuantityCommodity Scientific name (‘000 tonnes)Maize Zea mays 1,625,985Rice Oryza sativa 94,215Sorghum Sorghum bicolour 39,155Cotton Gossypium hirsutum 41,463Wheat Triticum aestivum L. 1,520Ground nuts Arachis hypogaea 759Soya beans Glycine max 31,373Pigeon pea Cajanus cajan 105,315Cowpeas Vigna unguiculata 26,119Bambara nuts Vigna sub terranean 7,039Chickpea Cicer arietinum 1,811Sunflower Helianthus annuus 4,107Source: Guide to Agricultural Production and NaturalResources Management in Malawi, 2002.CATFISH FEED INGREDIENTSFishmeal is one <strong>of</strong> the commonly usedanimal protein sources in catfish feeds.Fishmeal production in Malawi is very low.Dwindling fish catches from natural watersdo not satisfy the increasing demand andnot much fish remnants are available for fishfeed. As such, fishmeal is very expensive.Safalaoh (2002) reported a fishmeal unitcost <strong>of</strong> $0.46/kg compared with $0.25 forfull fat soya bean meal. Assuming the crudeprotein content <strong>of</strong> 60 percent for fishmealand 38 percent for full fat soya bean meal,protein from these sources cost $0.77 and$0.66 per kilogram, respectively. Most <strong>of</strong>the fishmeal used is imported from othercountries such as South Africa and Chile.Use <strong>of</strong> animal by-products from processingplants and slaughter-houses, such as blood,meat and bone meal is limited due to thelow supply (Safalaoh 2002).Soya bean meal is the most popularsource <strong>of</strong> protein in fish feeds. Soya beanproduction in Malawi was low in 1990because <strong>of</strong> the low price <strong>of</strong> the commodityon the market. However, in recent years,the production has perked up significantly,following the high demand for it by animalfeed producers. Fish farmers are realizingthe importance <strong>of</strong> feeding fish with soyabean-based feeds. They are advised tocombine one part <strong>of</strong> soya bean meal tonine parts <strong>of</strong> cereals (maize bran). Trials areunderway to develop plant-based fish feedformulations using soya bean as one <strong>of</strong> themain sources <strong>of</strong> protein.Other oilseed meals and grain legumesthat could be utilized in catfish feed includesunflower cakes, cottonseed cakes andgroundnut cakes, pigeon peas, cowpeasand chickpeas. However, their use could belimited by inadequate supply.PRIORITY AREASAND LIKELY FUTUREDIRECTIONSPROMOTION OF CATFISHPRODUCTIONThe special air-breathing characteristics,together with extra hardiness and rapidgrowth to large size, make the fish anextremely suitable species for aquaculturedevelopment in Malawi. Catfish is one <strong>of</strong> thefour fish species promoted for culturing inMalawi. Since most fish farmers are sparselydistributed, the ability <strong>of</strong> catfish to utilizeatmospheric air enables transportation <strong>of</strong>this fish over long distances without a specialoxygen-supplying facility. The catfish’sability to prey on other fish could be usedas a means to control tilapia reproductionto avoid overcrowding in fishponds. Oncethe problem <strong>of</strong> nursing fry to the fingerlingstage is solved, catfish production is likelyto boom significantly.PRODUCTION SYSTEMSMalawi is committed to implement researchprograms on this species. The major focuswill be on developing breeding and rearingtechnologies, conducting research oncatfish feeds, and on growth performance<strong>of</strong> catfish in polyculture systems with tilapiaspecies. Project results by ADiM (2005a)indicate that the polyculture <strong>of</strong> Clariasgariepinus with Oreochromis shiranus leadsto larger Oreochromis shiranus as a result<strong>of</strong> reduced competition for food and anincreased production <strong>of</strong> Clarias gariepinus.The National Aquaculture Strategic Plan(2006–2011) (Government <strong>of</strong> Malawi 2005)recommended aggressive promotion <strong>of</strong>the polyculture <strong>of</strong> Clarias gariepinus andOreochromis shiranus as a future viablealternative aquaculture production systemfor Malawi. It further recommended the

STATUS OF CATFISH PRODUCTION IN MALAWI 47National Aquaculture Center to initiateon-farm participatory trials to producefingerlings.HATCHERY OPERATIONSThe government encourages private sectorparticipation in catfish fingerling production.It needs to develop guidelines that will guidehatchery operations nation-wide in order toaccredit catfish fingerling hatcheries. Thegovernment <strong>of</strong> Malawi, with support fromFAO, implemented a technical cooperationprogram to support small-scale catfishfish farming enterprises as one such effortto develop small-scale catfish hatcheries.Future directions will need to scale up thehatchery and grow-out activities for catfish.BREEDINGThe promotion <strong>of</strong> catfish production will bepursued in parallel with the developmentand implementation <strong>of</strong> a national catfishbreeding program.CONCLUSIONCatfish species <strong>of</strong>fer a promising opportunityto contribute to food security andsocioeconomic development <strong>of</strong> the nation.However, incorporation <strong>of</strong> catfish productioninto aquaculture in Malawi has been relativelyslow. Prospects for its development areencouraging because <strong>of</strong> the existing highmarket demand, development <strong>of</strong> secondaryindustries such as fish feed manufacturing,and commitment from the government topromote its development. Despite theseprospects, however, there is an urgent needto perfect the technologies for on-farmproduction. In addition, catfish productionshould go in tandem with a breedingprogram that will improve its performanceunder various culture environments.REFERENCESAquaculture Development in Malawi (ADiM). 2005a.ADiM Working Paper, No. 2. Situation analysis<strong>of</strong> aquaculture in Malawi, Master Plan Studyon Aquaculture Development in Malawi(ADiM).Aquaculture Development in Malawi (ADiM). 2005b.ADiM Working Paper No 3. NationalSocioeconomic Survey Report, Master PlanStudy on Aquaculture Development in Malawi(ADiM).Environmental Affairs Department (EAD). 2002.Lake Chilwa Wetland, State <strong>of</strong> the Environment,Government <strong>of</strong> Malawi.Food and Agriculture Organization. 2003. FisheriesCircular No. 886 Rev 2 Food and AgricultureOrganization, Rome, 96 p.Harvey, B. and E.M. Carolsfeld. 1993. Inducedbreeding in tropical fi sh culture. InternationalDevelopment Research Centre, Ottawa.Haylor, G.S. 1992. African catfi sh hatchery manual.Central and Northern Regions Fish FarmingProject, Malawi. Stirling Institute <strong>of</strong> Aquaculture,University <strong>of</strong> Sterling, Scotland.Hecht, T.W.U and P.J. Britz. 1988. The culture <strong>of</strong>sharptooth catfi sh, Clarias gariepinus in SouthernAfrica. A Report <strong>of</strong> National Programme forAquaculture Research. Southern Africa NationalScientific Programmes Report No. 153.Foundation for Research Development. CRIR,Pretoria, South Africa.Hecht, T. and W. Lublinkh<strong>of</strong>. 1985. Clarias gariepinusx Heterobranchus longifi lis (Clariidae: Pisces):a new hybrid for aquaculture? South AfricanJournal <strong>of</strong> Science 81: 620–621.Japanese International Cooperation Agency (JICA).2004. Final Technical Report for the Project onAquaculture Research and TechnicalDevelopment <strong>of</strong> Malawian IndigenousSpecies.Japanese International Cooperation Agency (JICA).2001. Technical Report for the Project onScreening for Malawian Indigenous Species forAquaculture Development.Legendre, M., G. Teugels, C. Cauty and B. Jalabert.1992. A comparative study on morphology,growth rate and reproduction <strong>of</strong> Clariasgariepinus (Burchell 1822) and Heterobranchuslongifi lis (Valenciennes 1840) and their reciprocalhybrids (Pisces, Clariidae). Journal <strong>of</strong> FishBiology 40: 59–79.

48 PROCEEDINGS OF A WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSMalawi, Government <strong>of</strong>. 2002. Guide to AgriculturalProduction and Natural Resource Management.Ministry <strong>of</strong> Agriculture and Food Security,Lilongwe, Malawi.Malawi, Government <strong>of</strong>. 2004. Policy Statementon Livestock in Malawi. Department <strong>of</strong> AnimalHealth and Livestock Production, Lilongwe,Malawi.Malawi, Government <strong>of</strong>. 2005. National AquacultureStrategic Plan (2006–2011). Ministry <strong>of</strong> Mines,Natural Resources and Environment, Department<strong>of</strong> Fisheries, Lilongwe, Malawi.Maluwa, A.O., A.C. Brooks and B.B. Rashidi. 1995.Production <strong>of</strong> the Malawi chambo, O. karongae(Trewavas 1941) association and Oreochromisshiranus (Boulenger 1896) in polyculture withthe African catfi sh (Burchell 1822). AquacultureResearch 26: 103-108.Safalaoh, A. 2002. Protein sources for the animalfeed industry. Paper presented at ExpertConsultation and <strong>Workshop</strong>, 29 April – 3 May2002, Bangkok. Food and AgricultureOrganization (FAO), 2004.Skelton, P. 2001. A complete guide to the freshwaterfi shes <strong>of</strong> Southern Africa. Struik Publications,Cape Town, South Africa.Snoeks, J. 2004. The non-cichlid fi shes <strong>of</strong> the LakeMalawi system: a Compilation, pp 20-26. In J.Snoeks (ed.) The cichlid diversity <strong>of</strong> Lake Malawi/Niassa: identification, distribution andtaxonomy.Teugels, G.G. 1983. La structure de la negeioreadipeuse duas les genres Dinotopteroides,Heterobranchus et Clarias (Pisces, Siluriformes,Claridae) Cybium 7(1): 11-14.Teugels, G.G. 1995. Taxonomy, phylogeny andbiogeography <strong>of</strong> catfishes (Ostariophysi,Siluroidei): An Overview. Aquatic LivingResources 9: 9–34.Teugels, G.G., Ozouf-Costaz, M. Legendre andM. Parrent. 1992. A karyological analysis <strong>of</strong>artifi cial hybridization between Clarias gariepinus(Burchell 1822) and Heterobranchus longifi lis(Valenciennes 1840) (Pisces, Clariidae). Journal<strong>of</strong> Fish Biology 40: 81–86.

STATUS OF AFRICAN CATFISH FARMING IN NIGERIA 49STATUS OF AFRICAN CATFISH FARMING IN NIGERIAS.B. Williams 1 , B.D. Olaosebikan 2 , A.O. Adeleke 3 and O.A. Fagbenro 41Department <strong>of</strong> Agricultural Economics, Obafemi Awolowo University, Ile-Ife, Nigeria2Federal College <strong>of</strong> Freshwater Fisheries Technology, New-Bussa, Nigeria3Federal Department <strong>of</strong> Fisheries, Abuja, Nigeria4Department <strong>of</strong> Fisheries and Wildlife, Federal University <strong>of</strong> Technology, Akure, NigeriaABSTRACTThis paper presents the status <strong>of</strong> the catfishfarming industry in Nigeria. The industry isresponsible for 70 percent <strong>of</strong> aquacultureproduction, Clarias gariepinus being themost widely cultured species. Production <strong>of</strong>fingerlings and feed, especially floating feed,are major constraints that pose significantchallenges to the industry. Priority areasand likely future directions are suggested.INTRODUCTIONNigerians consume an estimated 1.3 milliontonnes <strong>of</strong> fish annually with a per capitaconsumption <strong>of</strong> 7.512 kg. Meanwhile,national production from both capturefisheries and aquaculture stands at 450,000tonnes. Over 800,000 tonnes <strong>of</strong> fish areimported to meet the annual demand(AIFP 2004a). Catfish farming and, indeed,aquaculture <strong>of</strong>fer strong potential forgrowth to meet the national fish demand,thereby reducing importation, providingemployment, alleviating poverty, and helpingto meet the Millennium Development Goals.This potential is great because Nigeria isendowed with over 12 million hectares<strong>of</strong> inland water and suitable soil for fishfarming. After the Fish for All Summit <strong>of</strong>2005 in Nigeria, the awareness and interestin fish farming has increased tremendously.Over 5,000 prospective farmers havebeen trained in nation-wide fish farmingworkshops in five geo-political zones <strong>of</strong>the country with as many as 40 percentadopting the practice almost immediately.The federal government recently launchedthe implementation <strong>of</strong> the Catfish IndustryValue Chain Development through a$34-million 5 loan facility through the WorldBank (public-private partnership initiative).This highlights the growing importance <strong>of</strong>the catfish industry in Nigeria.The catfish species that are culturedinclude Clarias gariepinus, C. anguillaris,Heterobranchus bidorsalis, H. longifilis, C.isheriensis, C. submarginatus, Chrysichthysnigrodigitatus, Bagrus sp. and Synodontissp., but C. gariepinus is undoubtedly the fish<strong>of</strong> choice for farmers. C. gariepinus is themost cultured fish in Nigeria and, indeed,Africa, and third in the world (Garibaldi1996). It can then be inferred that Nigeriais the highest global producer <strong>of</strong> this clariidcatfish. Research on the development <strong>of</strong>farming technology <strong>of</strong> C. gariepinus hasbeen carried out in Europe (i.e. Belgium andthe Netherlands) as well as in Africa, namelythe Central African Republic, Ivory Coastand South Africa (Hetch et al. 1996). Nigeriahas benefited the most by far from theseresearch activities due to several factors: thehigh demand for fish from almost 140 millionNigerians; the fish being found in every part<strong>of</strong> country and relished compared to carpand tilapia that were first introduced foraquaculture in Nigeria; and the maintenance<strong>of</strong> its quality when smoked dried. Its hardinessis due to the presence <strong>of</strong> an air-breathingorgan, its omnivorous feeding habit, andability to withstand adverse environmentalconditions. In addition, its high fecundityand the availability <strong>of</strong> mass artificial seedtechniques (Haylor 1992; and Hecht et al.1996) facilitate its culture without fear <strong>of</strong>overpopulation by uncontrolled breeding,such as in tilapia. The diversification <strong>of</strong>culture environments including concrete5All fi gures given as dollars ($) refer to US dollars.

50 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUStanks, fiber glass tanks and, more recently,water re-circulation systems (WRS) haveresulted in catfish production overtakingtilapia culture in Nigeria.OVERVIEW OF COUNTRYPRODUCTIONThe quantity <strong>of</strong> catfish producedfrom aquaculture in Nigeria is grosslyunderestimated as a result <strong>of</strong> many factorsincluding lack <strong>of</strong> capacity for data collection,reluctance and lack <strong>of</strong> transparency <strong>of</strong> somefarm owners, and the fact that many catfishare consumed by the households thatproduce them. The percentage <strong>of</strong> catfishproduction in the total fish production overmore than a decade is shown in Figure 1.There has been a steady increase in theproduction <strong>of</strong> catfish since the mid-nineties.Catfish accounts for 70 percent <strong>of</strong> fishproduction from aquaculture in Nigeria.PRODUCTION SYSTEMSCatfish farming can be divided into two broadcategories depending on the organization,input and level <strong>of</strong> intensification. The firstcategory is the small-scale farmer thatpractices catfish farming as a sole businessor on a part-time basis, employing relativelyunsophisticated techniques. The parttimefarmers are the most common. Feedconsists mainly <strong>of</strong> household or farm waste,compounded or in an earthen fishpond,depending on fertilization and naturalproduction. The levels <strong>of</strong> intensification arelow and, consequently, so are the yields.The second group is the large commercialfarmers that produce catfish using tankswith varying degrees <strong>of</strong> aeration and recirculation.Among this group are highlysophisticated intensive re-circulationsystems developed with foreign technicalassistance. These commercial farms aremainly concentrated in and around urbancenters and use imported brood stock(Dutch Clarias) and feed. The InternationalFinance Corporation (IFC), a World Bankgroup, has predicted that catfish productionin Nigeria will increase by 40,000 tonnesbefore 2010 with $160 million in income (IFC2007). There is a need and much scope forresearch on the possibilities <strong>of</strong> establishingefficiently run large-scale sole catfishenterprises because the present ones areintegrated with other agro-allied industries.According to a 2003 survey (Aquacultureand Inland Fisheries Project 2004a), thereare 2,658 fish farms in Nigeria, 2,152 <strong>of</strong>which culture catfish alone or in polyculturewith Oreochromis niloticus and Heterotisniloticus. Generally, 77 percent <strong>of</strong> thesefarms are found in the south <strong>of</strong> the country.The regional distribution <strong>of</strong> catfish farms inNigeria is shown in Figure 2. The southwestgeopolitical region has the highest number<strong>of</strong> farms followed by south-south (mainlyin the Delta State). It is important to notethat the high number <strong>of</strong> farms in the southsouthis mainly due to the terrain (i.e. riverine60,00050,000All fishCatfishMetric tonnes40,00030,00020,00010,00001990 1992 1994 1996 1998 2000 2002 2004Figure 1: Annual fish production from aquaculture in Nigeria (FAO 2007)

STATUS OF AFRICAN CATFISH FARMING IN NIGERIA 51floodplain) with many natural ponds that areput to use by the people. The northeasthas the lowest number <strong>of</strong> catfish farms dueto the supply <strong>of</strong> cheaper fish from capturefisheries in Lake Chad. In the southwest,catfish farming is so developed that mostfarmers practice monoculture and haveformed themselves into associations andcooperatives. Some <strong>of</strong> these associationsdate back to the late 1980s. A study <strong>of</strong> somefish farmers in Oyo state (southwest) showedthat the majority (46.7%) <strong>of</strong> the respondentsmake use <strong>of</strong> earthen ponds, while 20 percentand 33 percent use flow-through and recirculationponds, respectively (Olagunju etal. 2007).Various receptacles including earthen ponds,tanks made <strong>of</strong> concrete, fiber glass, plasticand aluminum are used in farming catfishin Nigeria with culture environments rangingfrom extensive with little or no supplementalfeeding to intensive with a complete waterre-circulatory system. Two main systemsare presently popular in Nigeria, the pondand concrete tanks, but there is a growingtrend towards the use <strong>of</strong> concrete tankswith or without aeration as they ensurewater conservation, reduce feed wastageand facilitate better management. Theadvantages <strong>of</strong> the recently applied waterre-circulation system over the simple wellaeratedconcrete tank are yet to be proven.The gradual change in Nigeria from theearthen pond system to the concrete tanksystem is one <strong>of</strong> the factors for the rapiddevelopment observed in the industry overthe last few years.SEED PRODUCTIONHigh quality catfish seed in large quantitiesis important to the development andsustainability <strong>of</strong> the growing catfish industryin Nigeria. Although there is no breedingcenter in Nigeria, there are several federalandstate-owned hatcheries. Most catfishseed production is from small-scaleoperators and a few large commercialfarms. Since the government hatcheries areeither in a state <strong>of</strong> disrepair or are producingbelow capacity, this creates an opportunityfor private investment in seed production.The distribution <strong>of</strong> these hatcheries isshown in Figure 3. The number from thesouthwest is underestimated, because nodata are available for the states <strong>of</strong> Oyo andOsun which have a substantial number <strong>of</strong>catfish farms.Fingerling production in Nigeria hasincreased ten-fold from 3-million/year in2000 to an estimated 30 million in 2005,making fingerling sales valued at anestimated $2.32 million (AIFP 2005). Much<strong>of</strong> the seed are produced by small-scalehatcheries that produce between 60,000 to200,000 fingerlings annually, using mainlythe Ovaprime hormone during the three t<strong>of</strong>ive months <strong>of</strong> the normal catfish breedingseason (i.e. May-September). These smallhatcheries have been shown to have apr<strong>of</strong>itability index in the range <strong>of</strong> 0.49-2.52 (Olagunju et al. 2007). The five largehatcheries, on the other hand, producearound 3-4 million fingerlings all year-round,using a controlled induced spawning method900800700600680771ClariasHeterobranchus5004594003002001000227989695334918 110Southeast South-South Southwest Northwest Northcentral NortheastFigure 2: Regional distribution <strong>of</strong> catfish farms in Nigeria (Based on AIFP 2003 survey)

52 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSin an intensive re-circulating system. Theprice <strong>of</strong> a 2-3 cm fingerling sells for $0.11each on average, while those <strong>of</strong> 4-6 cm cost$0.23 each.The small-scale producers are driven mainlyby pr<strong>of</strong>it and care little about the quality <strong>of</strong>their seed. Many hatcheries either collectbrood stock from the wild or use siblings<strong>of</strong> the previous year’s production withattendant inbreeding and introgression. Asthere is no way a grow-out farmer can detectpoor quality seed at the point <strong>of</strong> collection,many procure fry or fingerlings with poorgrowth and survival rates. This problemhas discouraged many grow-out farmersor made them go into seed production withlittle or no knowledge <strong>of</strong> genetics and fishbreeding.MARKETING SYSTEMSThe marketing structure <strong>of</strong> catfish cultureis mainly informal and, therefore, economicdata are not available. Catfish fromaquaculture in Nigeria are sold fresh. Forthe large commercial farms, sales are madethroughout the year, <strong>of</strong>ten on a weeklybasis. But most farms harvest the catfishon an irregular basis in an “all-in-all-out”manner. This sometimes results in a glutas most farmers breed catfish during therainy season and harvest some six monthsafter. Meanwhile, some private individualshave started fish processing and storagespecifically targeting the industry. Theirstrategy is to work through a catfish farmers’association to get farmers to utilize theirprocessing facilities. Presently, the countryis the largest market for farmed catfish asthere is still a huge demand, even thoughthe annual production pattern is skewed toa few months in the year. The market pricefor a kilogram <strong>of</strong> fresh catfish currentlyranges from $2.70 to $3.10 while smokeddried ones are higher.FEED AND NUTRITIONNigeria produces around 3.4 million tonnes<strong>of</strong> animal feed annually, although themajority <strong>of</strong> this is for the poultry industry.Less than 1 percent (25,000 tonnes) <strong>of</strong> thisfeed is for fish (AIFP 2004b). Catfish feedis the second most important input in theindustry after the seed, accounting for up to40 percent and 60 percent <strong>of</strong> the productioncost, respectively (Fagbenro 1987; Satia1990). C. gariepinus has a relatively highdietary protein requirement. Feeding witha formulated feed is a prerequisite forintensive monoculture <strong>of</strong> the African catfish.The best growth rates and food conversionsare achieved with diets containing 35-42percent <strong>of</strong> crude protein and a calculateddigestible energy level <strong>of</strong> 12 kJ g -1 (ADCP1983). A review <strong>of</strong> the animal and aquafeedindustries in Nigeria made by Fagbenroand Adebayo (2005) revealed that mostcatfish feeds are farm-made, using locallyavailable ingredients such as maize, soyabean, fishmeal, blood meal, rice bran, fishoil and wheat <strong>of</strong>fal. Other unusual feedstuffsinclude maggots, termites, earthworms andcrickets. There is presently no exclusiveaquafeed mill, and commercial catfishfeeds are produced by livestock millers insmall quantities and mostly on demand. In70606250404430201002217114Southeast South-South Southwest Northwest Northcentral NortheastFigure 3: Regional distribution <strong>of</strong> catfish hatcheries in Nigeria (Based on AIFP 2003 survey)

STATUS OF AFRICAN CATFISH FARMING IN NIGERIA 53recent years, an estimated 4,000 tonnes <strong>of</strong>commercial fish feed were imported annuallyfrom Europe, mainly from Denmark and theNetherlands.RESEARCH AND TRAININGIN AQUACULTUREFisheries research and training are theresponsibilities <strong>of</strong> Fisheries ResearchInstitutes and their affiliated colleges,although federal and state Department <strong>of</strong>Fisheries also contribute to human resourcesdevelopment through short-term trainingprograms and sponsorship <strong>of</strong> trainees. TheNigerian Institute for Oceanography andMarine Research (NIOMR) is the agency<strong>of</strong> the federal government established toconduct research on the resources andphysical characteristics <strong>of</strong> Nigerian territorialwaters and the EEZ. Its activities amongothers include brackishwater aquacultureresearch. African Regional AquacultureCenter (ARAC), at Aluu, Port Harcourt, is asubstation <strong>of</strong> NIOMR where its brackishwateraquaculture research and training activitiesare based. The Federal College <strong>of</strong> Fisheriesand Marine Technology (FCFMT), Lagos,started as a division <strong>of</strong> NIOMR, but is nowautonomous and has a mandate to trainmiddle-level experts for the fisheries sector.The National Institute for FreshwaterFisheries Research (NIFFR), New-Bussa,has the mandate for inland water resourcesand freshwater aquaculture. Research oncatfish farming technology at this institutedates back to the early 1980s with workon Clarias anguillaris and in the 1990s onC. gariepinus, Heterobranchus and theirhybrids. The Federal College <strong>of</strong> FreshwaterFisheries Technology (FCFFT), New-Bussaand Baga, is based on the shores <strong>of</strong> LakeChad. Both <strong>of</strong> these colleges train middlelevelexperts on inland capture fisheriestechnology and aquaculture management.Many universities in Nigeria are involvedin training and research on fisheries andaquaculture, but currently none is dedicatedsolely to catfish research.PAST AND CURRENTRESEARCH ON CATFISHBREEDING AND GENETICSThe culture <strong>of</strong> catfish, like every species,depends, among other things, on soundbrood stock management and the continuousselection <strong>of</strong> desirable traits. Clariasgariepinus, the desired culture species, isclosely related to Clarias anguillaris, bothbelong to the same genus (Teugels 1982,1986). The two species are sympatric inNigeria with very little external differencebetween them (Benech et al. 1993; Rognonet al. 1998; and Teugels 1998) and areonly distinguished morphologically by thenumber <strong>of</strong> gill rakers on the first branchialarch. In C. gariepinus, the number is high(up to 110) while in C. anguillaris it is lower(less than 50). In both species, the gill rakernumber increases with the standard length(Teugels 1986 and 1998). At the genetic100919080706050403235 363020181030Southeast South-South Southwest Northwest Northcentral NortheastFigure 4: Regional distribution <strong>of</strong> feedmills in Nigeria (Based on AIFP 2003 survey)

54 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSlevel, the two species are also very closewith a Nei’s genetic distance <strong>of</strong> 0.16 (Rognonet al. 1998) and P distance 0.04 (Nwafiliand Gao 2007). One consequence <strong>of</strong> thesimilarity between these two species is thatmany farmers are inadvertently culturing C.anguillaris and contaminating the gene pool<strong>of</strong> C. anguillaris and C. gariepinus throughinter-specific hybridization. This suspicionwas confirmed by a recent study on thegenetic characteristics <strong>of</strong> the Dutch strain <strong>of</strong>C. gariepinus from five hatcheries in Nigeriathat showed contamination <strong>of</strong> the exoticgene pool with local strains <strong>of</strong> C. anguillarisassociated with unwholesome hatcherypractices (Nwafili and Gao 2007). Apart frommisidentification, Nwafili and Gao (2007)gave economic reasons for this practice,citing obtaining Clarias from the wild, andthen maintaining brood stock coupled withthe cost <strong>of</strong> exotic C. gariepinus fingerlingsthat are about 40 percent higher than thosesold as C. gariepinus.HYBRIDIZATIONIntra- and inter-specific hybridizationstudies have been conducted in Nigeria onthe same catfish species (Aluko and Shaba2000; Madu and Aluko 2000; and Dadaand Wonah 2003). Madu and Aluko (2000)reported significant growth performanceand survival <strong>of</strong> C. gariepinus x C. anguillarishybrids over their parents. The F1 and F2backcross hybrid <strong>of</strong> H. longifilis and C.anguillaris has been shown to be infertile.The comparative advantage <strong>of</strong> these hybridsand their importance to aquaculture is yet tobe demonstrated.OTHER TECHNIQUESSome work has been done in the area <strong>of</strong>genetic manipulation <strong>of</strong> catfish, but all havebeen at an experimental level and have notbeen translated into real production. Forinstance, Aluko (2000) induced triploidyusing the H. longifilis and C. anguillarishybrid. According to Olufeagba et al. (2000a),using temperature to induce triploidy in H.longifilis, the best results from cold shocking<strong>of</strong> fertilized eggs were obtained at 5ºC for40 minutes while 39ºC for 3 minutes wasthe optimum for warm shock. The survivalpercentage <strong>of</strong> triploid fingerlings was 88.8percent, compared to 51.3 percent fordiploid fingerlings. The result from induceddiploid meiogynogenesis <strong>of</strong> H. longifilisshowed 25 percent hatchability, comparedto 53 percent for normal fish (Olufeagba etal. 2000b).PRIORITY AREASAND LIKELY FUTUREDIRECTIONSPOLICY AND LEGISLATIONPresently, there is no aquaculture policywhile the sole piece <strong>of</strong> legislation on it dealsonly with the importation <strong>of</strong> exotic species.The development <strong>of</strong> the correct policy andlegislation is an essential aspect that mustbe in place for effective and sustaineddevelopment <strong>of</strong> the industry. Even whenthese policies and laws are in place there willbe a need for a body to ensure enforcement,as experience has shown from existingfisheries laws. In order to stem the tide <strong>of</strong>indiscriminate contamination <strong>of</strong> the genepool <strong>of</strong> cultured catfish in Nigeria, there isneed for a national center that will have thecapacity to document genetic characteristics<strong>of</strong> all cultured catfish species.Such a center would also serve as anucleus breeding center where records <strong>of</strong>ancestry and crossbreeding <strong>of</strong> catfish and,indeed, <strong>of</strong> all cultured aquatic organismswould serve as a national aquaculturedatabase. The center would have thecapacity for cryopreservation <strong>of</strong> gametesfor the maintenance <strong>of</strong> breeds and strains,thus saving a lot <strong>of</strong> funds keeping live fish.Regional hatcheries would obtain broodstock from this center to produce seed tomeet the farmers’ needs. The center andassociated hatcheries should be managedon a public-private basis (better still, by aninternational organization with capacity infish breeding) in order to stem inefficiencyon the part <strong>of</strong> the government and prevent amonopoly on the part <strong>of</strong> a private company.The government can provide thesefacilities and pay staff remuneration, whilethe international agencies would providefunding for research activities so that theyare managed effectively.

STATUS OF AFRICAN CATFISH FARMING IN NIGERIA 55There should be legislation to stopindividuals from collecting seed fromthe wild or any other source, except theregional hatcheries, and to prevent arbitrarycross-breeding <strong>of</strong> farmed catfish. The lawshould also cover prevention <strong>of</strong> escapeto the wild <strong>of</strong> farmed fish. Legislation byitself may not be effective unless there isa conscious effort to promote responsiblepractices by strengthening catfish fishers’associations that will have the capacity forself regulation, policy advocacy, educatingits members and defending the interests<strong>of</strong> the industry. These associations canalso generate demand-driven research asopposed to what is presently undertaken atthe research centers.It is necessary to limit research to a few provencatfish species and research efforts shouldfirst be directed towards characterizingthe genetic variability <strong>of</strong> both the wildstocks and domesticated populations. Thetraditional method <strong>of</strong> selective breeding hasbeen recognized as an effective means <strong>of</strong>improving the performance <strong>of</strong> the fish and,hence, there is a need to employ advancedgenetic techniques to develop high yieldingstrains for the industry. This, however, willrequire considerable development <strong>of</strong> humanresources with the requisite capability inmodern genetics and genome research.CONCLUSIONThe future <strong>of</strong> catfish farming in Nigeria isbright and, compared to capture fisheries,is in a better position to improve livelihoods,provide food security, alleviate povertyand even become a foreign exchangeearner. However, the government <strong>of</strong> Nigeriamust put policies in place to ensure thatthe catfish industry is conducted in aresponsible manner. This requires carefulplanning, implementation and managementat federal, state and local government levels,with the guidance <strong>of</strong> international agenciessuch as the FAO and The WorldFish Center.The government should move further withthe enactment <strong>of</strong> laws providing guidelinesand regulations for the establishment<strong>of</strong> hatcheries, acceptable genetictechnologies, reliable sources <strong>of</strong> broodstock, record keeping and environmentalimpact assessment <strong>of</strong> aquaculture facilities.Such measures would safeguard againstunwholesome practices in the catfishindustry.REFERENCESAfrican Development Center for Aquaculture(ADCP). 1983. Fish feeds and feeding indeveloping countries — An Interim Report onthe ADCP Feed Development Programme.ADCP/REP/83/18 FAO, Rome 97 p.Akinwole, A.O. and E.O. Faturoti. 2007. Biologicalperformance <strong>of</strong> African catfi sh (Clarias gariepinus)cultured in re-circulating system in Ibadan.Aquacultural Engineering 36(1): 18-23.Aluko, P.O. 2000. Induction <strong>of</strong> triploidy inHeterobranchus and Clarias hybrids, p. 73-75.In A.A. Eyo, P.O. Aluko, S.A. Garba, U.D. Ali,S.L. Lamai and S.O. Olufeagba (eds.)<strong>Proceedings</strong> <strong>of</strong> the 12 th Annual Conference <strong>of</strong>the Biotechnology Society <strong>of</strong> Nigeria, New-Bussa.Aluko, P.O. 2001. Chromosomal and histologicalevidences <strong>of</strong> infertility in F2 and F2 backcrosshybrid generations <strong>of</strong> Clarias anguillaris andHeterobranchus longifi lis, p. 54-58. In A.A. Eyoand E.A. Ajao (eds.) <strong>Proceedings</strong> <strong>of</strong> the AnnualConference <strong>of</strong> the Fisheries Society <strong>of</strong> Nigeria,Ibadan.Aluko, P.O. and M. Shaba. 2000. Intra andinterspecific hybridization studies betweenexotic Clarias gariepinus and two indigenousclariid species. Nigerian Journal <strong>of</strong> Genetics14: 59-63.Aquaculture and Inland Fisheries Project (AIFP).2004a. Inventory <strong>of</strong> fish farms in Nigeria.Technical report (Annex II) <strong>of</strong> the Nigerian SpecialProgramme for Food Security (NSPFS),148 p.Aquaculture and Inland Fisheries Project (AIFP).2004b. Inventory <strong>of</strong> feed producers in Nigeria.Technical report (Annex II) <strong>of</strong> the Nigerian SpecialProgramme for Food Security (NSPFS), 65 p.Aquaculture and Inland Fisheries Project (AIFP).2005. Farming Nigeria’s waters. Technical noteNo. 16 <strong>of</strong> the Nigerian Special Programme forFood Security (NSPFS), 65 p.Benech, Abenech, V., G.G. Teugels and G.A.Gourene. 1993. Useful character to distinguishtwo African catfi shes, Clarias anguillaris and C.gariepinus (Siluriformes; Clariidae). Cybium(Paris) 17 (1): 83-85.Central Institute <strong>of</strong> Freshwater Aquaculture (CIFA).2004. Current economic opportunities inaquaculture in sub-Saharan Africa. CIFA/XIII/2004/8. Food and Agriculture Organization(FAO), Rome.

56 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSDada, A.A. and C. Wonah. 2003. Production <strong>of</strong>exotic Clarias gariepinus fi ngerlings at varyingstocking densities in outdoor concrete ponds.Journal <strong>of</strong> Aquatic Sciences 18: 21-24.Ewa-Oboho, I.O. and U.K. Enyenihi. 1999.Aquaculture implications <strong>of</strong> growth variation inthe African catfi sh: Heterobranchus longifi lis(Val.) reared under controlled conditions. Journal<strong>of</strong> Applied Ichthyology 15: 111-115.Fagbenro, O.A. 1987. A review <strong>of</strong> biological andeconomical principles underlying commercialfi sh culture production in Nigeria. Journal <strong>of</strong>West African Fisheries 3: 171-177.Fagbenro, O.A. and O.T. Adebayo. 2006. A review<strong>of</strong> the animal and aquafeed industries in Nigeria.In J. Moehl and M. Halwart (eds.) A synthesis<strong>of</strong> the formulated animal and aquafeeds industryin sub-Saharan Africa. CIFA Occasional PaperNo. 26. Food and Agriculture Organization(FAO), Rome, 61 p.Food and Agriculture Organization (FAO). 1997.Aquaculture development. 1. Good aquaculturefeed manufacturing practice. FAO TechnicalGuidelines for Responsible Fisheries, No. 5,Suppl. 1. Food and Agriculture Organization,Rome, 47 p.Food and Agriculture Organization (FAO). 2007.Aquaculture production statistics 2007. http://www.fao.orgGaribaldi, L. 1996. List <strong>of</strong> animal species used inaquaculture. FAO Fisheries Circular No. 914.Food and Agriculture Organization, Rome.Haylor, G.S. 1992. Some aspects <strong>of</strong> the biologyand culture <strong>of</strong> the African catfish, Clariasgariepinus with particular reference to developingAfrica countries. In R.J. Roberts and J.F. Muir(eds.) Recent advances in aquaculture Vol. IV.Blackwell Publications, Oxford.Hecht, T.I., L. Oeilerman and L. Verheust. 1996.Perspectives on clariid catfi sh culture in Africa.Aquatic Living Resources 9: 197-206.International Finance Cooperation (IFC). 2007. IDA/IFC African Small Business Initiative BeginsWith US$32 Million Nigerian Credit http://www.ifc.orgMadu, C.T. and P.O. Aluko. 2000. Hybrid mudfi shproduction: comparative growth and survival<strong>of</strong> hybrids and putative parents, p. 89-94. InA.A. Eyo, P.O. Aluko, S.A. Garba, U.D. Ali, S.L.Lamai and S.O. Olufeagba (eds.) <strong>Proceedings</strong><strong>of</strong> the 12 th Annual Conference <strong>of</strong> theBiotechnology Society <strong>of</strong> Nigeria, New-Bussa.Moehl, J., M. Halwart and R. Brummett. 2004.Report <strong>of</strong> the FAO-WorldFish Center workshopon small-scale aquaculture in sub-SaharanAfrica: revisiting the aquaculture target groupparadigm. CIFA Occasional Paper No. 25. Foodand Agriculture Organization (FAO), Rome.Nwafili, S.A. and T. Gao. 2007. Is the Dutchdomesticated strain <strong>of</strong> Clarias gariepinus(Burchell 1822) a hybrid? African Journal <strong>of</strong>Biotechnology 6: 1072-1076.Olagunju, F.I., I.O. Adesiyan and A.A. Ezekiel. 2007.Economic viability <strong>of</strong> catfi sh production in OyoState. Nigeria Journal <strong>of</strong> Human Ecology 21:121-124.Olufeagba, S.O., P.O. Aluko, J.S. Omotosho, A.Raji and B. Hassan. 2000a. Optimum conditionsfor inducing triploidy in Heterobranchus longifi lis(Val. 1840), p. 52-55. In A.A. Eyo, P.O. Aluko,S.A. Garba, U.D. Ali, S.L. Lamai and S.O.Olufeagba (eds.) <strong>Proceedings</strong> <strong>of</strong> the 12 th AnnualConference <strong>of</strong> the Biotechnology Society <strong>of</strong>Nigeria, New-Bussa.Olufeagba, S.O., P.O. Aluko and J.S. Omotosho.2000b. Effect <strong>of</strong> triploidy on fertility <strong>of</strong> Africancatfish Heterobranchus longifilis (Family:Clariidae). Journal <strong>of</strong> Fisheries Technology 2:43-50.Olufeagba, S.O., P.O. Aluko, J.S. Omotosho, S.O.Oyewole and A. Raji. 2001. Induced diploidmeiogynogenesis in the African Clariid catfi sh,Heterobranchus longifi lis (Valenciennes 1840)Pisces: Clariidae, p. 62-65. In A.A. Eyo andE.A. Ajao (eds.) <strong>Proceedings</strong> <strong>of</strong> the AnnualConference <strong>of</strong> the Fisheries Society <strong>of</strong> NigeriaIbadan.Rognon, X., G.G. Teugels, R. Guyomard, P.Galbusera, M. Andriamanga, F. Volckaert andJ.F. Agnese. 1998. Morphometric and allozymevariation in the African catfishes Clariasgariepinus and C. anguillaris. Journal <strong>of</strong> FishBiology 53:192-207.Satia, B.P. 1990. National reviews for aquaculturedevelopment in Africa, No. 29, Nigeria. FAOFisheries Circular, No.770.29. Food andAgriculture Organization (FAO), Rome, 193 p.Teugels, G.G. 1982. Preliminary results <strong>of</strong> amorphological study <strong>of</strong> fi ve African species <strong>of</strong>the subgenus Clarias (Clarias) (Pisces; Clariidae).Journal <strong>of</strong> Natural History: 434-64.Teugels, G.G. 1986. A systematic revision <strong>of</strong> theAfrican species <strong>of</strong> the genus Clarias (Pisces;Clariidae). Annales du Musee Royal de l’AfriqueCentrale 247:1-199.Tuegels, G.G. 1998. Intra- and inter-specificmorphometric variation in Clarias gariepinusand C. anguillaris (Siluroidei, Clariidae), p. 241-247. In J.F. Agnese (ed.) Genetics andaquaculture in Africa. Offi ce de la RechercheScientifi c et Technique Outre-Mer (ORSTOM),Paris.UNDP/The Equator Initiative. 2004. Lungfi sh toLagos – Nigeria. http://www.tve.org

THE CURRENT STATUS OF CATFISH CULTURE AND RESEARCH IN UGANDA 57THE CURRENT STATUS OF CATFISH CULTUREAND RESEARCH IN UGANDASemu David Matsiko (1) and Matthew Tenywa Mwanja (2)(1)Aquaculture Research and Development Center, Kajjansi, P.O. Box 530 Kampala,Uganda(2)Kyambogo University, P.O. Box 1, Kyambogo, Kampala UgandaABSTRACTThe paper discusses the status <strong>of</strong>catfish farming and research in Ugandaand highlights a strategy for a catfishimprovement program. It was compiledfrom the views and practices <strong>of</strong> aquaculturepolicymakers, research scientists, themain catfish hatchery proprietors and theirmanagers, and also from literature sources.Findings show that fish farming in general isstill at a subsistence level in output for growout,but is purely commercial for catfishhatchery operators. Catfish constitute 40percent <strong>of</strong> the total production. There areindications that most <strong>of</strong> the farmed catfishin Uganda are the subsequent generations<strong>of</strong> a small catfish founder population thatwas introduced into the country from Kenya.Also, findings show that no attempts havebeen made to assess the quality <strong>of</strong> catfish,neither has there been any improvementprogram in the country. This paper givesa review <strong>of</strong> the state <strong>of</strong> catfish production,highlights the past and current research oncatfish, and suggests priority areas and likelyfuture directions for catfish improvement inUganda.INTRODUCTIONAquaculture in Uganda started in 1953with the farming <strong>of</strong> indigenous fish species(Oreochromis niloticus and O. leucostictus).It was the frustration from their precociousreproduction and, therefore, stunting inponds that led to the introduction <strong>of</strong> thecommon carp (Owori 1 unpublished data).The primary objective <strong>of</strong> aquaculturedevelopment in the country at the timewas to address malnutrition among therural population. As such, fish farming hasremained at a subsistence level in operationand output to date.African catfish (Clarias gariepinus) hasrecently emerged as the most favoredspecies for aquaculture in Uganda. Itis particularly popular among fingerlingproducers for the bait industry. To the growoutfarmers, the main reasons given for ashift from tilapia to catfish farming are thatcatfish grow fast, enjoy a good market, bothdomestically and regionally. They are alsocredited with greater adaptability in poorwater quality conditions than tilapia and notreproducing naturally in ponds, resulting inhigh yields. Catfish currently contributes upto an estimated 40 percent <strong>of</strong> the aquacultureproduction in grow-out ponds in Uganda.Several constraints have been facing catfishculture in Uganda including: limited accessto brood stock; lack <strong>of</strong> technology for itscaptive breeding, and lack <strong>of</strong> formulatedfeeds. Some <strong>of</strong> these problems are nowbeing addressed. However, a number <strong>of</strong>factors such as brood stock quality andtheir management still remain and may beaffecting the performance <strong>of</strong> catfish in thecountry. Research in Eastern 2 and mid-Western Uganda has revealed deformedcatfish and in some cases, up to 2 percent<strong>of</strong> the fish in grow-out farms are deformed.In an attempt to understand the possiblecauses <strong>of</strong> these deformities, an investigationwas made into the history <strong>of</strong> catfish farmingin the country. It has now been found that1Owori Wadunde is a senior researcher at the Aquaculture Research and Development Center, Kajjansi.2Uganda is divided into four administrative regions: Northern, Eastern, Central and Western.

58 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSfew founder brood stocks <strong>of</strong> catfish (53)were introduced into the country from Kenya(Rutaisire 3 2007 personal communication),from which most <strong>of</strong> the farmed catfish inthe country were produced. Some catfishfarmers have introduced a few males fromthe wild to avert the likely inbreeding effects(Digo 4 2007 personal communication).These were, however, not geneticallycharacterized, although the commonly heldnotion is that cultured catfish in Uganda isC. gariepinus. Therefore, catfish species orstrains are not clearly classified.Most <strong>of</strong> the fingerlings go into the baitindustry, hence the biggest challenge forscientists and farmers in the country is to tryand tailor catfish production for grow-outrather than increasing the fishing effort onthe already dwindling stocks <strong>of</strong> Nile perch.Only then will the attention be focused onaddressing the quality <strong>of</strong> catfish fingerlingsproduced. This paper therefore, gives areview <strong>of</strong> the state <strong>of</strong> catfish production,highlights the past and current research onTable 1: Catfish production by region in the countryRegionProduction (tonnes)Western 1,964.7Eastern 1,333.6Central 2,074.4Northern 1,153.0Source: DFR 5 (2007).catfish, and suggests priority areas and likelyfuture directions for catfish improvement inUganda.OVERVIEW OF COUNTRYPRODUCTIONAccurate estimates <strong>of</strong> actual productionare difficult due to the fragmented nature<strong>of</strong> fish farming in the country, lack <strong>of</strong>proper record keeping by farmers andthe inefficiency <strong>of</strong> government agriculturalextension services. A spectacular trendis that in the last ten years aquacultureproduction and particularly catfish cultureand production has been steadily increasing(Figure 1). Information from the Department<strong>of</strong> Fisheries Resources indicates that catfishproduction has risen to 40 percent <strong>of</strong> thetotal aquaculture production. Productioncapacity by region is given in Table 1.INDUSTRY STRUCTUREThere is only one national-level public center,the Aquaculture Research and DevelopmentCenter (ARDC) at Kajjansi with the mandateto conduct aquaculture research <strong>of</strong> nationalstrategic importance. There are also fivezonal public fish fry production centersbased in different agro-ecological regions(in the northern, West Nile, eastern, westernTonnes (x1000)60504030201001950 1960 1970 1980 1990 2000YearsFigure 1: Total aquaculture production for the last ten years (Megapesca 2006)3Dr. Justus Rutaisire is the Head, Aquaculture Research and Development Center, Kajjansi, and also acatfi sh hatchery operator.4T. Digo is a fi sh farmer and the proprietor <strong>of</strong> the Sun Fish Farm, the biggest catfi sh hatchery in thecountry.5Department <strong>of</strong> Fisheries Resources (DFR) in the Ministry <strong>of</strong> Agriculture Animal Industry and Fisheries.

THE CURRENT STATUS OF CATFISH CULTURE AND RESEARCH IN UGANDA 59and southwestern parts <strong>of</strong> the country) witha mandate to replicate and tailor aquacultureresearch to address local requirements. Thezonal centers, however, lack facilities andhuman resources for aquaculture research,but ARDC is adequately equipped to meetresearch needs. Catfish breeding has notbeen a focus <strong>of</strong> attention until 2007. This isbecause the center had a limited number <strong>of</strong>staff members, and there was a perceptionthat selective breeding in catfish was noturgently needed because the growth ratewas higher compared with tilapia speciesin the same culture period in Uganda. BothARDC and the zonal centers are involved invery limited fry production to supply farmerswithin the country and the respectiveregions. The regional centers have broodstocks <strong>of</strong> catfish, tilapia and a few C. carpio,while ARDC, in addition, has stocks <strong>of</strong>Bagrus docmac, Nile perch, Barbus speciesand Labeo species.HATCHERIES AND PRODUCTIONCAPACITYThere are a number <strong>of</strong> small part-timehatcheries, but only ten are full-time andkeep records <strong>of</strong> production. The averagenumber <strong>of</strong> brood stock is about 100. Somehatcheries do not even keep brood stock;they only buy brood stock from otherhatcheries at the time they want to producefry. Data from five regularly reportinghatcheries indicate increasing numbers <strong>of</strong>fingerlings. The total number <strong>of</strong> fingerlingsproduced in 2006 was estimated at onemillion. The total production per month in2007 is estimated at 200,000 (FISH project 62007). The range <strong>of</strong> production capabilityis estimated at 2,000-7,000 fingerlings perkilogram <strong>of</strong> the female’s body weight. Thesehatcheries are all involved in induced catfishbreeding. Most <strong>of</strong> them employ certificate ordiploma holders with training in general fishfarming from the Fisheries Training Institute,Entebbe.Fingerlings for both grow-out and baitpurposes are mostly from the five mainhatcheries and, to a lesser extent, fromthe wild. Both small- and medium-scalehatcheries supply fingerlings withoutrestrictions because there is no clear policythat regulates the quality <strong>of</strong> fry or fingerlingsin Uganda. Unfortunately, the parentalbreeders used to produce fingerlings forsale and restocking their ponds are limitedin order to cut down production costs.Most <strong>of</strong> the hatcheries have employedinduced-breeding techniques, and someuse chemicals continuously to preventor treat diseases. For “fear <strong>of</strong> disease”outbreaks and the resulting losses thatthey may incur, some hatcheries keep fry informalin throughout their hatchery life. Thisis beginning to raise health concerns forconsumers.PRODUCTION SYSTEMSUp to 18 percent (43,942 sq. km) <strong>of</strong> Uganda’sland mass is freshwater (i.e. major and minorlakes, rivers, swamps and reservoirs). Themost commonly used production system ispond culture for grow-out, and the number<strong>of</strong> ponds has been increasing since 1999(as shown in Figure 2 below).Tanks are used mainly for the production<strong>of</strong> fingerlings as bait for Nile perch as wellas for grow-out. Cage farming is still atan experimental level on Lake Victoria bythe FISH project. An EU-funded projectcalled BOMOSA is also experimenting withcage culture in small reservoirs in EasternUganda. Despite cage culture trials, thereis no legislation providing for cage culturein the country and there is no factoryproducing high quality floating feeds for use.Trials by the FISH project are dependent on35,00030,00025,00020,00015,00010,0005,000Ponds01999 2001 2003 2005Figure 2: Increase <strong>of</strong> pond culture from 1999 to 20056Fisheries Investment for Sustainable Harvest (FISH) project is a USAID-funded project in Ugandaimplemented by Aurban University.

60 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSimported floating feeds from the USA. It isimportant to note that Lake Victoria has hadan incident <strong>of</strong> water hyacinth proliferation,a sign that it has a high level <strong>of</strong> nutrients.Development <strong>of</strong> commercial cage cultureon the same lake with low quality feeds maylead to further eutrophication for the biggestfreshwater body in Africa. BOMOSA usessinking feeds produced in the country withhigh fiber content (Figure 3) that is likely tohave serious water quality implications onthe receiving waters.SCALE OF PRODUCTION BYSECTORS: STATE, PRIVATE,JOINT VENTURE AND OTHERSThe majority <strong>of</strong> grow-out farmers arepracticing subsistence farming. Differentcategories <strong>of</strong> farmers in Uganda are indicatedin Table 2. Small-scale commercial farmerspractice both semi-intensive and intensivelevels <strong>of</strong> production.Both subsistence and small-scalecommercial farmers are private producersand use formulated feeds from Ugachick.Government institutions are involved mainlyin the provision <strong>of</strong> extension services,research and, to a limited extent, fish seedproduction.Table 2: Scales <strong>of</strong> aquaculture production in UgandaScaleProduction levelSubsistenceExtensiveSmall-scale commercial Semi-intensiveIntensiveOn-farm trials in Eastern and CentralUganda show catfish yields <strong>of</strong> 18-20 t/ha with Ugachick poultry breeder feedsproduced in the country. Cage productiondata available show yields <strong>of</strong> between 135and 173 kg/m 3 for 1 m 3 and 2 m 3 volumecages, respectively.MARKETING SYSTEMSMarketing <strong>of</strong> farmed fish in the countryincludes pond sites, local and urban centers.Regional markets are now being targeted,especially for the fingerlings destined as baitfor Nile perch on Lake Victoria among thethree countries <strong>of</strong> East Africa. It is importantto note that the marketing <strong>of</strong> farmed fish inUganda is not well organized. Farmed andcapture fisheries fish are all sold in the samemarket, at the same stalls, except for thosesold at the pond site. This makes it difficult tosell farmed fish at a reasonable price whencompared with fish from capture fisheries,considering the high production costsinvolved in fish farming. However, effortsat the research center to teach farmers tosmoke their fish, which increases both theshelf-life and their earnings, have startedto pay <strong>of</strong>f. Also, farmers are encouragedto sell farmed fish live. This strategy isyielding results because fish from capturefisheries is normally <strong>of</strong> rather poor qualitydue to the methods used in its capture andtransportation to markets. Catfish is beingexported to the DR Congo after gettingpermits from the Ministry <strong>of</strong> Agriculture,Animal Industry and Fisheries (MAAIF 7 ).Figure 3: Ugachick Poultry Breeder’s feeds before and after dissolving in water7Department <strong>of</strong> Fisheries <strong>of</strong> MAAIF

THE CURRENT STATUS OF CATFISH CULTURE AND RESEARCH IN UGANDA 61Farmed fish have not yet penetrated theEuropean Union (EU) market because <strong>of</strong>the stringent EU standards set, but theGovernment <strong>of</strong> Uganda is hopeful, since thesame market accepts fish from Uganda’scapture fisheries.PROBLEMS, ISSUESOR CONSTRAINTSThe challenges <strong>of</strong> catfish farming in thecountry still remain, but plans and effortsare underway to address them. Thesechallenges include:• Very low survival both in the hatcheryand grow-out farms• Lack <strong>of</strong> capacity to identify and treatemerging hatchery diseases by usingincorrect or inappropriate drugs• Deformities observed in grow-out pondsin the eastern and western parts <strong>of</strong> thecountry• Little or no knowledge in geneticprinciples <strong>of</strong> managing brood stockamong fingerling producers and extension<strong>of</strong>ficers• The quality <strong>of</strong> brood stock is not knownor uncertain (genetic studies on farmedor wild catfish have not been done at all)• Lack <strong>of</strong> quality feeds and inadequatequantity <strong>of</strong> feeds• Poor and inadequate extension services• Poor management <strong>of</strong> the productionsystems leading to low yields thatdiscourage the catfish industryPAST AND CURRENTRESEARCH ON CATFISHThere has been limited advancement incatfish research in the country. This isbecause the research center has beenstruggling with problems <strong>of</strong> understaffing,limited experience and expertise inaquaculture research, as well as inadequatefunding. The following have either beenaccomplished or are on-going:• Determining the economic feasibility <strong>of</strong>catfish production in Eastern and mid-Western Uganda (on-going)• The use <strong>of</strong> “shooters” as brood stock incatfish farming: study on cannibalisticbehavior and fast growth (on-going)• Determination <strong>of</strong> the carrying capacity <strong>of</strong>catfish ponds with static water (on-goingby FISH project)• Comparative growth rate trials <strong>of</strong> O.niloticus, C. gariepinus and C. carpio fedon formulated diet (Kajjansi Aquafeed)and two commercial feeds in unfertilizedponds (past)• Use <strong>of</strong> poultry waste (<strong>of</strong>fal) for C.gariepinus culture in earthen ponds(past)FEED AND NUTRITIONTwo private companies manufacture fishfeeds in the country: Ugachick PoultryBreeders Limited and NUVITA. NUVITAproduces for one fish farm (Source <strong>of</strong> theNile), while Ugachick produces and sellsto all fish farmers. All the feeds producedso far are the sinking pellet type with ahigh fiber content. Feeds for fish larvae areimported into the country by Balton Ugandamaking them expensive and untenable forupcoming hatchery operators.LOCAL RESOURCES:AGRICULTURALPRODUCTS, LOCALFEEDSTUFFAgricultural products in Uganda include:sunflower, soya, maize and rice bran,millet and sorghum. The animal proteinsource for the feeds is mainlyRasteneobola agentae (mukene) that islikely to become an environmental andfood security issue in the near future.

62 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSNUTRITIONAL STUDIESON CATFISHNutritional studies referred to here have beenconducted by Fisheries Training Institutestudents supervised by ARDC Kajjansi staffat the station.• Comparative growth rate trials <strong>of</strong> O.niloticus, C. gariepinus and C. carpio fedon Kajjansi Aquafeed and two commercialfeeds in unfertilized ponds. O. niloticusand C. gariepinus performed better onKajjansi aquafeed followed by Ugachickand lastly Bulemezi (slow and weaker).Growth <strong>of</strong> C. capio was highest onUgachick feed followed by Bulemezi.With the help <strong>of</strong> scientists from AuburnUniversity on the FISH project, the quality<strong>of</strong> Ugachick feed has been improved.• Use <strong>of</strong> poultry waste (<strong>of</strong>fal) for C.gariepinus culture in earthen ponds.Results: It was feasible and economicalto raise fish on <strong>of</strong>fal (22.7 t/ha), but anunexpected problem was that the catfishbecame too fatty.MANAGEMENT:PRODUCTION CYCLEFROM BREEDING,NURSING, REARINGTO GROWING OUTBrood stock management does not takeinto account genetic principles, even thoughattempts are made during breeding to usemore than one male for egg fertilization. Thetendency has been to try to match the broodstock weight <strong>of</strong> females with those <strong>of</strong> malesduring the operation. The male pituitarygland is used to induce the females. Somehatcheries are employing formalin (1,000ppm) on fertilized eggs for prophylaxisagainst hatchery diseases. Rudimentaryrecirculation systems (i.e. bottle tops andaggregate stones as bi<strong>of</strong>ilter material) arebeing used in hatcheries, although othersare still using the flow-through system.Feeding <strong>of</strong> fry was originally done with livefeeds produced locally in the hatcheries.Later, artemia was adopted by a few well-tod<strong>of</strong>armers and now artemia are replacingother feeds (from Balton Uganda).Farmers use starter feeds for one month onstocked fingerlings and later switch to growerfeeds for the grow-out stage. Fingerlingsare mostly transported in large open plastictanks with aeration from the hatcheries tothe farms. Plastic bags in which pure oxygenhas been pumped are still being used forfingerling transportation to grow-out farms.Most farmers have adopted manufacturedfeeds, although some are still using on-farmproduced feeds due to the high cost <strong>of</strong> theformer.PRIORITY AREASAND LIKELY FUTUREDIRECTIONSFor increased and sustainable catfishproduction through culture in Uganda, it isrecommended that the following issues beaddressed in the very near future:• Immediate introduction <strong>of</strong> brood stockfrom the wild for interbreeding with thoseavailable in culture units to improve thequality <strong>of</strong> catfish fingerlings as a mitigationmeasure. However, a long-term plan fora selective breeding program beginningwith genetic characterization <strong>of</strong> thestrains in the wild and those in cultureunits (public sector) should be initiated.• Collaboration with reputable researchscientists and institutions worldwide tobuild up capacity to develop and sustainsound breeding programs• Raising awareness <strong>of</strong> the need for goodbrood stock management practicesamongst hatchery managers and growoutfarmers• Working with private feed industries toaddress the lack <strong>of</strong> starter feeds forcatfish fry and to improve the quality <strong>of</strong>grower feeds (partnership with Ugachickto avail them with an extruder areunderway)• Encouraging young scientists to train infish health and disease management

THE CURRENT STATUS OF CATFISH CULTURE AND RESEARCH IN UGANDA 63CONCLUSIONFurther development <strong>of</strong> the catfish industryin Uganda will require genetic improvement<strong>of</strong> the brood stock for key traits <strong>of</strong>commercial importance. A commitment toa long-term program <strong>of</strong> selective breedingis, therefore, needed to transfer improvedgenes from the nucleus to the commercialpopulations. Attempts should be made inareas <strong>of</strong> molecular genetics and genomicssuch as population characterization, linkagemapping, genome sequencing <strong>of</strong> catfishspecies or strains in the country. Developingcapacity to use molecular markers willcontribute to enhance efficiency <strong>of</strong>conventional selection methods.REFERENCESMegapesca Lda – Portugal. 2006. Aquaculture inUganda: A review <strong>of</strong> the sub-sector and strategyfor its development. A consultancy reportsubmitted to the Ministry <strong>of</strong> Agriculture, AnimalIndustries and Fisheries (MAAIF).Ministry <strong>of</strong> Agriculture, Animal Industries andFisheries (MAAIF). 2007. Ministry <strong>of</strong> Agriculture,Animal Industries and Fisheries PolicyStatement.

64 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSCLARIAS CATFISH: BIOLOGY, ECOLOGY,DISTRIBUTION AND BIODIVERSITYRandall E. BrummettSenior ScientistThe WorldFish Center-CameroonHumid Forest Center, B.P. 2008 (Messa), YaoundéCAMEROONINTRODUCTIONCatfishes <strong>of</strong> the genus Clarias (Siluroidei,Claridae) are widespread in tropical Africaand Asia. Having evolved in the Plioceneepoch (upper Tertiary period) some 7–10million years BP (Sudarto 2007), there arenow 58 species recognized in FishBase(as <strong>of</strong> October 2007), all living in freshwater(Annex A), but able to tolerate salinities up to2.2 ppt (Clay 1977). They are characterizedby a rather eel-shaped body, long dorsaland anal fins, lack <strong>of</strong> a dorsal fin spine, noadipose fin (except a vestigial remnant in C.ngamensis) and four pairs <strong>of</strong> barbels (Figure1).The synapomorphic characteristic <strong>of</strong>the family Clariidae, which also includesthe genera Bathyclarias, Channallabes,Clariallabes, Dinotopterus, Dolichallabes,Encheloclarias,Gymnallabes,Heterobranchus, Horaglanis, Platyallabes,Platyclarias, Uegitglanis and Xenoclarias isthe suprabranchial organ (Teugels 2003),formed by folds <strong>of</strong> the second and fourthbranchial arches. With this organ, whichfunctions like a lung, Clarias species areable to practice aerial respiration and canthus tolerate very low dissolved oxygenand even survive long periods out <strong>of</strong>water, provided their suprabranchial organremains moist. Even under conditions<strong>of</strong> dissolved oxygen saturation, Clariidsrely on atmospheric oxygen for about50% <strong>of</strong> their needs, increasing to 80-90%under low dissolved oxygen conditions(Moreau 1988). Juveniles, apparently dueto underdeveloped suprabranchial organs,depend on dissolved oxygen for 90% <strong>of</strong>their needs (Lévêque and Quensière 1988).ECOLOGYClarias species probably evolved in tropicalswamp forest ecosystems (Sudarto 2007)but now occupy a wide range <strong>of</strong> habitatsfrom cascading mountain streams anddeep lakes to swampy holes. However, theyare especially fond <strong>of</strong> slow-flowing lowlandstreams, shallow lakes, swamps, ponds,ditches, rice paddies and pools left in lowspots after rivers have been in flood. Manyspecies seem to prefer stagnant, muddywater, where their suprabranchial organgives them a competitive advantage overspecies requiring higher concentrations<strong>of</strong> dissolved oxygen (Jackson et al. 1988).In larger waterbodies, Clarias seem toFigure 1: A typical Clarias species, C. gariepinus (FishBase 2007)

CLARIAS CATFISH: BIOLOGY, ECOLOGY, DISTRIBUTION AND BIODIVERSITY 65prefer marginal weedy areas (Daget 1988;Welcomme and de Merona 1988).The ability to breathe atmospheric oxygen,the elongated body form and strong pectoralspines are used by Clarias species to wriggleover land and, coupled with the ability toleap considerable vertical distances, invadenew waterbodies or escape from stressfulconditions. Most such movement occurs atnight.Members <strong>of</strong> the genus Clarias are omnivoresand are highly opportunistic feeders, takingalmost anything they can fit into theirmouths (Lauzanne 1988). Stomach contents<strong>of</strong> Clarias species typically include insects(adults and larvae), worms, gastropods,crustaceans, small fish, aquatic plants anddebris, but terrestrial seeds and berries,and even birds and small mammals, havealso been observed. C. cavernicola reliesheavily on bat droppings for its nutrition.Larvae are almost exclusively dependent onzooplankton for the first week <strong>of</strong> exogenousfeeding (Hecht 1996). Large C. gariepinus,courtesy <strong>of</strong> their high number gill rakers, havebeen reported to also target zooplankton asa primary food source (de Graaf and Janssen1996). Although generally omnivorous,Clarias spp. are relatively better at digestinghigh-protein diets than carbohydrates(Wilson and Moreau 1996).Most species <strong>of</strong> Clarias are slow foragingpredators, with very small eyes, using theirfour pairs <strong>of</strong> barbels to feel their way aroundin the dark (Boujard and Luquet 1996) andfind food detected by the array <strong>of</strong> sensitivetaste buds covering the barbels and head(Garg et al. 1995). Approximately 70% <strong>of</strong>feeding activity takes place at night (Hossainet al. 1999). Research done in South Africareported by de Graaf and Janssen (1996)showed that removal <strong>of</strong> the barbels reducedfeeding efficiency in C. gariepinus by 23%. Ingeneral, Clarias catfishes capture their preyby gulping them with a rapid opening <strong>of</strong> themouth and then retaining them either on thegill rakers or fine recurved teeth arrangedon dentary, premaxillary, vomerine andpharyngeal bands (Bruton 1979).C. gariepinus, one <strong>of</strong> the more successfulClarias species based on extent <strong>of</strong> its nativerange, exhibits a variety <strong>of</strong> feeding strategiesincluding sucking the surface for terrestrialinsects and plant fragments washed intothe water by heavy rains and pack-hunting<strong>of</strong> small cichlids (Bruton 1979).Growth in Clarias species is relativelyrapid, with most species approaching theirmaximum size within a couple <strong>of</strong> years.Most Clarias species are relatively r-selected(altricial) with medium to high resilience(population doubling time <strong>of</strong> 15–30 months)and rapid growth to relatively early sexualmaturity, high fecundity and a (anticipated)short lifespan (Hecht 1996). First year growthin the larger, k-selected species (e.g., C.gariepinus) is nearly linear resulting in thelarge initial jump in size shown in Figure 2(de Merona et al. 1988). See also Table 1.REPRODUCTIONMany Clarias species undertake lateralmigrations from the larger waterbodies inwhich they feed and mature, according toLegendre and Jalabert (1988) at about theage <strong>of</strong> 2 years under natural conditions(but sometimes 7–8 months in captivity),to temporarily flooded marginal areas toTable 1: von Bertalanffy growth estimation parameters for two Clarias species (de Merona et al. 1988)Species Location Sex L ∞(mm) k aT o(years)C. gariepinus Limpopo M 1,564.8 0.084 -2.35C. gariepinus Boskop Dam M 1,366 0.171 -0.782C. gariepinus Boskop Dam F 1,950.5 0.090 -1.090C. gariepinus Shire River M 1,320 0.093 -0.737C. gariepinus Shire River F 577.6 0.310 -0.383C. gariepinus Lake Sibaya M 759.5 0.349 0.036C. gariepinus Lake Sibaya F 672.5 0.517 1.234C. gariepinus Lake Are (Egypt) M/F 1,154.9 0.110 -0.614C. ngamensis Shire River M 1,147.8 0.085 1.589C. ngamensis Shire River F 628.6 0.215 -0.659C. ngamensis Lake Liambezi M 523.6 0.408 -2.631C. ngamensis Lake Liambezi F 511.4 0.328 -3.525

CLARIAS CATFISH: BIOLOGY, ECOLOGY, DISTRIBUTION AND BIODIVERSITY 67worthingtoni) ) species flock in Lake Malawi,range in size from 60 to 135 cm, and havebeen tried in ponds (Msiska et al. 1991).Gymnallabes typus, native to the lowercourse and delta <strong>of</strong> the Niger River andCross River basin in Nigeria and Cameroon,has been tested as an alternative to eelsin trials in the Netherlands (Teugels andGourène 1998).Reaching over 1 m in length and 55 kg inweight (Skelton 1993), the non-ClariasClariid that has received the most attentionby fishfarmers and is actually producedin a number <strong>of</strong> African countries, isHeterobranchus longifilis. Otémé et al. (1996)report that, under optimum conditions, H.longifilis grows twice as fast as C. gariepinus.This species, known as vundu in southernAfrica, is found throughout Africa in the Nile,Niger, Senegal, Congo, Gambia, Benué,Volta and Zambezi River systems as well asall the coastal basins from Guinea to Nigeria,and in Lakes Tanganyika, Edward and Chad.Of particular interest has been the hybridbetween H. longifilis and C. gariepinus first produced in South Africa and commonlyknown as the “heteroclarias”.GENETIC DIVERSITY INCULTURED STOCKSAs with other cultured species, domesticationor captive holding on fishfarms has resultedin a certain amount <strong>of</strong> genetic change,usually deterioration. Da Costa (1998) founda 20% difference between cultured and wildstocks <strong>of</strong> C. anguillaris, with the culturedstock performing significantly worse. Otémé(1998) and Agnèse et al. (1995) found thata population <strong>of</strong> H. longifilis held for fourgenerations on a government researchstation had reduced genetic variability,lower fry growth rate and survival, higherlevels <strong>of</strong> fry deformity, and greater variabilityin larval growth rate. Van der Bank (1998)found that mean heterozygosity in a captivepopulation (0.3%) <strong>of</strong> C. gariepinus wasan order <strong>of</strong> magnitude less than in a wildpopulation (5%). H<strong>of</strong>fman et al. (1995) foundthat wild C. gariepinus grew 15–43% betterunder culture conditions than populationsthat had been held on-farm. Van der Waltet al. (1993a) reviewed genetic variability inC. gariepinus and found strong evidence <strong>of</strong>inbreeding, founder effects and genetic driftin most captive populations.Good genetic management can reversemany <strong>of</strong> these negative consequences<strong>of</strong> domestication and even improveperformance. Van der Bank et al. (1992)and Grobler et al. (1997) showed thatoutcrossing to other captive stocks andwith wild fish raised mean heterozygosity<strong>of</strong> a farmed population to 7.6% comparedto 5% in a wild stock. Similarly, Teugelset al. (1992) found that populations <strong>of</strong>C. gariepinus that were purposefullyoutcrossed among research stations weresignificantly more heterozygous than fishheld in isolation on a single station. AmongC. gariepinus stocks, significant variationin growth indicates that selection for betterperformance in aquaculture is possible (Vander Bank 1998). Van der Walt et al. (1993b)showed that a well-maintained experimentalline <strong>of</strong> C. gariepinus outperformed wildstrains and a population held on a localhatchery. De Matos Martins et al. (2005)documented significant variation in growthamong juvenile C. gariepinus, implying thatselection is possible.Although two wild populations <strong>of</strong> C.macrocephalus and one <strong>of</strong> C. batrachus inMalaysia showed very low genetic variability(Daoud et al. 1989), and response to massselection for resistance to Aeromonashydrophila in C. macrocephalus in early trialsin Thailand showed little gain (Uraiwan 1993;na-Nakorn et al. 1994), Thai researchershave a selected line <strong>of</strong> C. macrocephalusthat grows 12% better than control lines.In Southeast Asia, hybrids betweenC. gariepinus and C. batrachus or C.macrocephalus have been widely produced,reportedly combining the faster growth <strong>of</strong>the African catfish with the more appealingculinary attributes <strong>of</strong> those from Asia(Uraiwan 1993).CONSERVATION STATUSMost members <strong>of</strong> the genus Clarias areunder no particular danger <strong>of</strong> extinction atpresent. Four species, all African, appearon the IUCN Red List <strong>of</strong> Threatened

68 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSSpecies (2007): C. alluadi, C. cavernicola,C. maclerni and C. werneri. The closelyrelated, and easily confused, C. alluadi andC. werneri (Seegers 1996) are consideredas <strong>of</strong> Least Concern, with widespreaddistributions and no particular threats. C.cavernicola and C. maclerni are consideredas Critically Endangered. C. cavernicola isendangered due to the fact that its entirerange is one pool <strong>of</strong> 45 m 2 in the Aigamascave, Namibia, and the water level is goingdown due to groundwater extraction in thearea. C. maclareni, while under no specificthreat, occupies one lake, Barombi-M’bo,on the slopes <strong>of</strong> Mt. Cameroon, an activevolcano.Although Clarias species are generally quitehardy, Mohamed et al. (1999) found thatsections <strong>of</strong> the Nile River which receivedheavy levels <strong>of</strong> industrial pollution containedsignificantly fewer C. gariepinus than othersections and attributed this to poor waterquality. As they are originally best adaptedto swamp forest habitats, Clarias speciesworldwide have come under increasingpressure as forests become increasinglyfragmented (Sudarto 2007).Interactions between farmed lines <strong>of</strong> Clariasand wild populations may represent asignificant threat to the genetic integrity <strong>of</strong>the latter. There appears to be a significantamount <strong>of</strong> genetic differentiation acrossthe distribution <strong>of</strong> C. gariepinus, withpopulations in West/Central Africa differingmorphometrically (width <strong>of</strong> premaxillarytoothplate, length <strong>of</strong> occipital process anddorsal fin length) from those in easternand southern Africa (Teugels 1998),possibly reflected in earlier taxonomicrecognition <strong>of</strong> three species, two <strong>of</strong> whichC. mossambicus and C. lazera, have sincebeen incorporated into C. gariepinus.Transcontinental movement <strong>of</strong> populationsused for aquaculture may pose a threat tothis differentiation.In Africa, the H. longifilis x C. gariepinushybrid, once thought to be sterile, hasbeen recently shown to have the capacityto interbreed with wild C. gariepinus,creating what is effectively a transgenicClariid, with unpredictable consequencesfor the wild populations, but quite possiblyincluding a reduction in overall fecundityand therefore fitness leading to reductionsin the wild stock (T. Hecht, pers. comm.,2005). Euzet and Pariselle (1996) found that“heteroclarias” juveniles were susceptible toHenneguya infections to which both pureHeterobranchus and Clarias were immune,raising further questions about the wisdom<strong>of</strong> creating this hybrid.In Asia, the widely produced C.macrocephalus and C. gariepinus hybrid has been escaping from fishfarmsand interbreeding with wild Clarias spp. formany years, causing widespread concernabout the effects <strong>of</strong> the introgression <strong>of</strong>C. gariepinus genes into the local species,lowering what is widely perceived to betheir better qualities as tablefish, andconsequently the economic value <strong>of</strong> thewild catch and the future value <strong>of</strong> wildgenetic material in aquaculture applications.In Thailand, the introduction and escapefrom aquaculture <strong>of</strong> the C. macrocephalusx C. gariepinus hybrid has been related tothe declines in wild stocks <strong>of</strong> C. batrachus.Conversely, escape <strong>of</strong> C. batrachus fromculture facilities has been linked to the virtualdisappearance <strong>of</strong> wild C. macrocephalus inthe Philippines (Main and Reynolds 1993;Lever 1996); likewise in Taiwan, where C.batrachus has interbred with the indigenousC. fuscus, which is now in serious declineas a pure species (Lever 1996).In addition to the dangers posed toindigenous biodiversity by these interspecificand intergeneric hybrids, concerns havebeen expressed about the possiblenegative consequences <strong>of</strong> escapeesfrom monogenetic but domesticatedculture populations reducing the fitness<strong>of</strong> conspecific wild populations. Themagnitude <strong>of</strong> this threat is proportional to thegenetic distance between wild and captivepopulations. If the difference is extreme,introgression <strong>of</strong> domesticated genomes intowhat is theoretically defined as a perfectlyfit wild population, unavoidably reduces thepurity <strong>of</strong> the wild genome. Whether sucha change in gene frequencies representsa real threat to survival is unknown. Bothin the wild and in captivity, shifting genefrequencies are a natural consequence <strong>of</strong>any significant change in the environment.

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Biodiversité et aquacultureen Afrique. Centre de RecherchesOcéanographiques, Abidjan, Côte d’Ivoire.Welcomme, R.L. and B. de Merona. 1988. Fishcommunities <strong>of</strong> rivers. p. 251-276. In C.Lévêque, M.N. Bruton and G.W. Ssentongo(eds.) Biology and ecology <strong>of</strong> African freshwaterfi shes. Editions de L’ORSTOM, Paris, France.Wilson, R.P. and Y. Moreau. 1996. Nutrientrequirements <strong>of</strong> catfi shes. Aquat. Living Resour.9 (Hors Série): 103-111.Young, M.J.A. and A.W. Fast. 1990. Temperatureand photoperiod effects on ovarian maturationin the Chinese catfish (Clarias fuscus). J.Aquacult. Trop. 5: 19-30.

CLARIAS CATFISH: BIOLOGY, ECOLOGY, DISTRIBUTION AND BIODIVERSITY 71ANNEX AClarias species, natural distribution, maximum reported size and status as an aquaculture species(FishBase 2007).MaximumSpecies Natural distribution reported Culture?Clarias abbreviatus Asia: Macau NoClarias agboyiensis Africa: Ofin and Volta systems, Ghana; coastal rivers, Togo; 29 cm/178 g NoOuémé River, Benin; Ogun and Oshun rivers, Niger delta;coastal rivers (especially Cross River), Nigeria.Clarias albopunctatus Africa: Lake Chad, upper Benué system, central Congo system. 19.5 cm NoClarias alluaudi Africa: Lakes Victoria, Kyoga, Edward, Rukwa and Tanganyika. 35 cm NoClarias anfractus Asia: Borneo, Malaysia. 17.6 cm NoClarias angolensis Africa: Lower and Central Congo system. 35 cm AquariaClarias anguillaris Africa: Nile; Lake Chad system including Logone and Shari rivers; 1 m/7 kg Experi-Niger and Benoué systems; coastal rivers in Benin, Togo, Ghanamentaland Côte d’Ivoire; Gambia and Senegal and Volta systems;relict populations in Mauritania and Algeria.Clarias batrachu Asia: Mekong and Chao Phraya basins, Malay Peninsula, 47 cm/1.2 kg YesSumatra, Java, Borneo, Sri Lanka (?)Clarias batu Asia: endemic to Pulau Tioman, Malaysia. 30.5 cm NoClarias brachysoma Asia: endemic to Sri Lanka. 50 cm/3.6 kg AquariaClarias buettik<strong>of</strong>eri Africa: Upper Gambia to the Agnebi River in Côte d’Ivoire. 19.2 cm NoGhana (?)Clarias buthupogon Africa: Congo system, Ogowe, Sanaga, Wouri, Cross and 90 cm Nocoastal rivers <strong>of</strong> Nigeria and Benin. Luongo River, Zambia (?)Clarias camerunensis Africa: coastal rivers Togo to the lower and central 46.6 cm NoCongo system. Ghana (?)Clarias cataractus Asia: Malay Peninsula.Clarias cavernicola Africa: Aigumas Cave, North Otavi, Namibia. 16.1 cm AquariaClarias dayi Asia: Wynaad Hills, Western Ghats <strong>of</strong> Kerala, India. Ombatta, 17.5 cm NoMudumalai, Tamil Nadu (?)Clarias dhonti Africa: Niemba and Koki rivers, west <strong>of</strong> Lake 18.5 cm NoTanganyika (DR Congo).Clarias dumerilii Africa: Central and Upper Congo and Luapula systems. 30.5 cm NoClarias dussumieri Asia: Goa, Karnataka, Kerala and Pondicherry in India. 25 cm NoClarias ebriensis Africa: Côte d’Ivoire to southeast Nigeria. 31.5 cm/240 g NoClarias engelseni Africa: Yei River, Sudan. 18.5 cm NoClarias fuscus Asia: China, Taiwan, Philippines, Viet Nam and Oceania: Hawaii 24.5 cm YesClarias gabonensis Africa: Lower and Middle Congo system, including Lake TumbaClarias gariepinus*and Pool Malebo; Chiloango and Ogowe River systems. 36 cm NoAfrica: almost Pan-Africa; absent from Maghreb, upper andlower Guinea, Cape and probably Nogal provinces.Asia: Jordan, Israel, Lebanon, Syria and Turkey. Widelyintroduced to other parts <strong>of</strong> Africa, Europe and Asia. 1.7 m/60 kg YesClarias hilli Africa: Middle Congo and Lake Albert. 19.6 cm NoClarias insolitus Asia: upper Barito River drainage in southern Borneo, Indonesia. 14 cm NoClarias intermedius Asia: Indonesia. NoClarias jaensis Africa: Ogowé River, Gabon; Sanaga, Nyong, Kribi, Ntem, Dja, 48.3 cm NoSangha rivers, Cameroon and southeast Nigeria.Clarias kapuasensis Asia: West Borneo, Indonesia. 26 cm NoClarias laeviceps Africa: Fouta Dialon (Guinea) and coastal rivers, Sierra Leone. 25.7 cm NodialonensisClarias laeviceps Africa: Saint Paul River, Liberia eastward to the Volta system. 31.7 cm NolaevicepsClarias lamottei Africa: Nzi River, Bandama system, Côte d’Ivoire. 16.4 cm NoClarias leiacanthus Asia: Indonesia. 33 cm NoClarias liocephalus Africa: Lakes Victoria, Edward, George, Kivu, Tanganyika, 32 cm NoMalawi, small lakes <strong>of</strong> Uganda, smaller lakes <strong>of</strong> Rwanda,Bangweulu-Moero, Kagera, Malagarazi, Ruzizi, Tana, Cunene,Okavango, upper Zambezi and Kafue River systems +Zambian Congo.Clarias longior Africa: Kribi, Lobi and Ntem rivers in south Cameroon. 22.5 cm NoClarias maclareni Africa: endemic to Lake Barombi-Mbo, NW Cameroon. 36 cm No

72 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSClarias species, natural distribution, ... cont’d.MaximumSpecies Natural distribution reported Culture?Clarias macrocephalus Asia: Thailand to Viet Nam. Introduced to China, Malaysia, 1.2 m YesGuam and Philippines.Clarias macromystax Africa: Oueme River, Benin; Ogun and Oshun systems, Nigeria; 31.6 cm NoNiger delta + Niger up to Lake Kainji and Benue River (Nigeria).Clarias meladerma Asia: Mekong to Indonesia and Philippines. 35 cm NoClarias microstomus Asia: Mahakam and Kayan river drainages in east Borneo. 14.1 cm NoClarias nebulosus Asia: Sri Lanka. NoClarias ngamensis Africa: Quanza, Cunene, Okavango, Chobe, Pungwe, Buzi, 73 cm/4 kg Experi-Save, Limpopo, Incomati, lower Pongolo, lower Sabi, Lundi,mentalKafue, upper Lualaba, Luapula, Zambian Congo, lower Shireand upper Zambezi (above Victoria Falls) river systems.Lakes Ngami, Malawi, Moero and Bangweulu.Clarias nieuh<strong>of</strong>ii Asia: Southeast Asia. 50 cm NoClarias nigricans Asia: Mahakam drainage, Borneo, Indonesia. 30.8 cm NoClarias Africa: central Congo system in Angola. 17.6 cm NonigromarmoratusClarias olivaceus Asia: Padang, Sumatra, Indonesia. 24.2 cm NoClarias pachynema Africa: coastal rivers <strong>of</strong> south Cameroon (up to Sanaga River); 35.6 cm NoOgowe system, Gabon and Middle Congo system.Clarias planiceps Asia: Belakin area, Ulu Sungai Anap, Sarawak, Malaysia 29.7 cm NoClarias platycephalus Africa: lower and central Congo basin, Lower Ntem River Basin (?) 37.6 cm NoClarias Asia: Borneo, Indonesia. 24.5 cm NopseudoleiacanthusClarias pseudonieuh<strong>of</strong>ii Asia: Borneo 31.6 cm NoClarias salae Africa: Konkoure system (Guinea) to the Cavally River 50.8 cm No(Côte d’Ivoire).Clarias stappersii Africa: Luapula-Moero, Kafue, upper Zambezi, Cunene, 41 cm NoOkavango; Zambian and Kasaï Congo river systems.Clarias submarginatus Africa: Kribi and Lobi rivers (south Cameroon) + Luongo and 16 cm NoCongo systems, Zambia.Clarias sulcatus Asia: Malaysia. 20.7 cm NoClarias teijsmanni Asia: Sundaland. 22 cm NoClarias theodorae Africa: Zambezi, Kafue, Shire rivers; Upper Congo, Chobe, 35 cm AquariaOkavango, Cunene, Pungwe, Sabi, Lundi, Zimbabweantributaries <strong>of</strong> the Limpopo, Incomati, Pongolo and Umgeni rivers;Lakes Tanganyika, Bangweulu, Kobo, Niumbe, Mweru,Malawi, Sibaya.Clarias werneri Africa: Lakes Victoria, Kyoga, Edward and Tanganyika. 23 cm NoBahr el Jebel, Sudan (?)* C. gariepinus populations from western and southern Africa exhibit a certain amount <strong>of</strong> genetic differentiation from eachother, probably indicating that this nearly pan-African species has begun to differentiate since the climatological andgeological events <strong>of</strong> the Miocene (~20 million years BP) isolated the once-contiguous populations (Rognon et al. 1998).

REPRODUCTIVE AND GROWOUT MANAGEMENT OF AFRICAN CATFISH IN THE NETHERLANDS 73REPRODUCTIVE AND GROWOUT MANAGEMENT OFAFRICAN CATFISH IN THE NETHERLANDSWilly Fleuren, M.Sc.DirectorFleuren and Nooijen Fishfarms Ltd.Jodenpeeldreef 25764RL De RipsTHE NETHERLANDSINTRODUCTIONThis paper describes two main areas <strong>of</strong>African catfish production: reproductiveand growout management. The technicalaspects <strong>of</strong> the paper are viewed from theperspective <strong>of</strong> a producer with many years <strong>of</strong>practical experience in fingerling productionin a European environment. The companyis named Fleuren and Nooijen FishfarmsLtd., based in the Netherlands. Its activitiesalso include design and construction <strong>of</strong>recirculation aquaculture systems (RAS)for a range <strong>of</strong> fish species (catfish, tilapia,ornamental fish), trading for aquaculturenecessities and consultancy.SELECTION,HYBRIDIZATION ANDMAINTENANCE OFBROODSTOCKFor many farmers broodstock managementis rarely paid due attention. Fish farmersor producers mainly focus on availabilityand price <strong>of</strong> fingerlings. A formal breedingprogram to improve broodstock does notexist in many countries. Scientific researchon genetics <strong>of</strong> African catfish is limited andis not well applied in practice. By far, massselection within families is <strong>of</strong>ten practised.Growth is the main criterion in selectionalthough other traits, such as efficiency <strong>of</strong>food use or survival, are also considered. Inthe particular context <strong>of</strong> Europe, dressingpercentage and meat quality emerge aseconomically important traits.At Fleuren and Nooijen Fishfarms Ltd., themass selection program in African catfishhas been carried out for several generations.The pure Clarias gariepinus has been widelycultured in the Netherlands. In addition, theelite parents from this program are usedto cross with Heterobranchus longifilis toproduce fry or fingerling hybrid as a finalproduct for commercial purposes. Thehybrid is named Heteroclarias. They cannotbe used for reproduction by customers.They also have other growing advantages,such as higher dressing yield and nichemarket product for better price. However,the hybrid exhibited aggressive behaviorand large variation in body weight. Althoughthis scheme has been working quite well,there are also problems with the selection<strong>of</strong> broodstock. It is impossible to know theexact identity <strong>of</strong> the fish. There is no way tocontrol or restrict inbreeding accumulation.The level <strong>of</strong> genetic variation in the populationis also not monitored or estimated.Besides selection, the maintenance<strong>of</strong> broodstock is another importantcomponent for catfish production. Efficientuse <strong>of</strong> breeders saves expenses andlabor. Necessities for good broodstockmaintenance include development <strong>of</strong>traceability methods (e.g., electronictagging), optimization <strong>of</strong> husbandrysystems, and appropriate feeding regimeand nutrition.

74 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSREPRODUCTIONThe productivity <strong>of</strong> females generally dependson weight, age, spawning frequency andmanagement (water quality, feed, feeding,stress) <strong>of</strong> individuals. The relative fecundity<strong>of</strong> females is approximately 5–12% <strong>of</strong> theirbody weight. On average, there are about500 eggs per gram <strong>of</strong> body weight in the fishpopulation <strong>of</strong> Fleuren and Nooijen Fishfarms.The egg size increases with weight and age<strong>of</strong> the females. Experience shows that use <strong>of</strong>females should start when they exceed 1.5years <strong>of</strong> age. Induction <strong>of</strong> hormones usinghuman chorionic gonadotropin (HCG) orcatfish pituitaries should be applied to ripenand mature fish. Maturation time dependson temperature. Around 25 °C is optimal.Determining the optimal time for strippingis critical—too early or too late may havenegative effect on hatching rate.Sperm production in males is alwayspresent without hormone induction.Stripping the males still remains impossibledue to the physiology <strong>of</strong> the testis. Malesare <strong>of</strong>ten sacrificed as they undergo anoperation to remove sperm. Fresh spermcan be preserved in 0.9% saline solution in arefrigerator (4 °C) for a maximum <strong>of</strong> 24 hours.For cryopreservation and conservationpurposes, sperm (not embryo) can be storedin a cryoprotectant agent in liquid nitrogen(-173 °C). Important genetic materialsshould be cryoconserved for future need.Until now, methods <strong>of</strong> cryopreservation forpractical use in catfish hatcheries have notbeen available.The procedure <strong>of</strong> artificial fertilization inAfrican catfish is quite simple. Eggs andsperm are first collected in dry porcelain orglass bowls. Often, 0.25 ml sperm is addedto 100 g <strong>of</strong> eggs. Then 100–200 ml water ismixed and gently stirred for 1 minute. Also,note that no sperm-life extenders are used.HATCHERY MANAGEMENTBASED ON RECIRCULATIONAQUACULTURE SYSTEMSSuccessful hatcheries are very pr<strong>of</strong>itable.The success rates <strong>of</strong> hatcheries varyenormously, ranging from 5 to 200 eggsto grow one juvenile. Indoor recirculationsystems (RAS) are widely used in Europe(especially the Netherlands) to cultureAfrican catfish, although other systems alsoexist such as ponds or flow-through.The basic principles <strong>of</strong> RAS include removal<strong>of</strong> solid particles, spilled feed, dissolvedorganic matter and CO 2, conversion <strong>of</strong>ammonium into the less harmful nitrate(nitrification) or conversion <strong>of</strong> nitrate intoN 2gas (denitrification). The general designfeatures and a schematic overview <strong>of</strong>RAS are illustrated in Figures 1 and 2,respectively.The use <strong>of</strong> RAS in hatcheries, however,has both advantages and disadvantages.The advantages <strong>of</strong> RAS include bettercontrol <strong>of</strong> environment and diseases.Feeding efficiency <strong>of</strong> RAS is high. Thereis no predation. It is also easy to grade,take care and harvest the fish. RAS needs1 Fish tank2 Sedimentation tank3 Pumptank4 Biotower5 Reception tankH HeaterPump45Sedimentation tankWaste waterDentrificationNO 2N 2(g)Fish tankFeedAirNitrificationNH 4NO 2NO 3Pump tankBi<strong>of</strong>ilterO 2CO 212 3 HFigure 1: General design features <strong>of</strong> RASWaterEnergyFigure 2: Schematic overview <strong>of</strong> RAS

REPRODUCTIVE AND GROWOUT MANAGEMENT OF AFRICAN CATFISH IN THE NETHERLANDS 75limited space for installation. A bore hole isused as the only water source. On the otherhand, RAS also requires intensive capitalinvestment, high-quality infrastructure, andhigh running costs and feed quality.Overall, the sections in a hatchery, basedon RAS, are designed specifically forbroodstock, incubation, and advancedfry and juvenile. The specific life stages <strong>of</strong>African catfish in RAS are shown in Table 1.Technical specifications (e.g., system,tank material and size) and managementparameters (e.g., stocking density, feeding,light regime, production cycle and watersource) required for broodstock, incubation,and advanced fry and juvenile arerespectively given in Tables 2, 3, 4 and 5.Feeds and feeding are critical factors forpr<strong>of</strong>itable farming <strong>of</strong> African catfish basedon RAS. Different types <strong>of</strong> feeds arerequired for larvae, advanced fry, juvenileTable 1: Feed and water quality parameters required for different rearing stages <strong>of</strong> African catfishGrowth Age Optimal water quality parametersphase (weeks) Weight System Feed NH 4NO 2pH Temp. ( o C)Fry – larvae 0–2 0.05–0.1 g Incubation Dry dietsystem 0.2–0.3 mm

76 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSand brooders. With high-quality extrudedfeed, the fish can perform fast growth, lowfood conversion ratio (FCR), high survivalrate and low deformities. The economics<strong>of</strong> fry, advanced fry and juvenile feeding isgiven in Table 6, which indicates that buyinggood quality feed is not expensive.Grading during early stages <strong>of</strong> rearing isessential for African catfish because this is acarnivorous species displaying cannibalismfrom the fry stage. Cannibalism is themain cause <strong>of</strong> high mortality in hatcheries.Suboptimal (or poor) rearing conditions alsoinduce development <strong>of</strong> shooters. Gradingshould be carried out once or twice duringadvanced fry stage and once during juvenilestage.Another issue with RAS is maintenance andmanagement. Without proper maintenance,problems can arise gradually in initial stagesand can become serious later. For technicalaspects, it is necessary to monitor waterparameters regularly by periodic flushing,cleaning and disinfection. There should bea pest control program, maintenance <strong>of</strong>infrastructure, repair <strong>of</strong> farm equipment,presence <strong>of</strong> spare parts, cleaning <strong>of</strong>environment and proper record keeping <strong>of</strong>the whole production process.DISEASESDiseases are related to rearing environmentsand management practices. Curing withmedicine is a symptomatic solution only. Thecause <strong>of</strong> any disease should be identifiedat the farm level. Threats for African catfishinclude toxins (CO 2, NO 2, NH 4, chemicals),element deficiencies, overfeeding,parasites, bacteria and viruses. When thefish suffer from toxins, they show signs <strong>of</strong>hanging, brown blood, quick mass mortality,increase or decrease <strong>of</strong> slime and nervousbehavior. Treatment in these cases includesflushing, salt application and ventilation.Generally, farmers don’t pay good attentionto deficiencies in vitamin, minerals, fattyor amino acids. In severe cases, the fishcan stop feeding and growing or can showsluggish behavior and deformities (e.g.,broken heads). Immediate reaction includesfeed improvement and better feed storage.Table 6: Economics <strong>of</strong> fry, advanced fry and juvenile feedingFryProduction 100,000 fry <strong>of</strong> 0.1 gFCR 0.6 Survival 40%Feed Quantity *Price/kg TotalArtemia 2 kg € 55 € 1100.2–0.3 mm dry feed 7.2 kg € 20 € 144Total € 254Price per fry € 0.003Advanced Production 100,000 advanced fry <strong>of</strong> 1 gfry FCR 0.6 Survival 58%Feed Quantity Price/kg Total0.3–0.5 mm and 65 kg € 4 € 2600.5–0.8 mm dry feedTotal € 260`Price peradvanced fry € 0.003Juvenile Production 100,000 juveniles <strong>of</strong> 8.0 gFCR 0.7 Survival 75%Feed Quantity Price/kg Total0.8–1.2 mm and 550 kg € 3 € 1.6501.2–1.5 mm dry feedTotal € 1.650Price perjuvenile € 0.02* Prices are indicative only and based on 2007 data; €1.0 equivalent to US$1.33 January 2007;€1.0 equivalent to US$1.46 December 2007.

REPRODUCTIVE AND GROWOUT MANAGEMENT OF AFRICAN CATFISH IN THE NETHERLANDS 77Overfeeding is not recommended becausethe digestive system <strong>of</strong> the fish cannotcope with the feeding level or method.Typical symptoms <strong>of</strong> overfed fish includeopen bellies, sluggish behavior, hanging ormortality. For parasites, there are gill andskin worms or flagellates. The fish showabnormal signs such as cotton-like spotson body, inactive or sluggish behavior,increase <strong>of</strong> slime and nervous behavior.Under these situations, salt treatment andincrease <strong>of</strong> water temperature are needed.There are two main bacterial diseases:aeromonas and citrobacter-related origins.The fish show symptoms such as ulcers onskin, necrosis <strong>of</strong> barbles, inactive feeding,sluggish behavior, hanging, and limited tosevere mortality. They should be treatedusing antibiotics along with sterilization<strong>of</strong> the environment and improvement <strong>of</strong>management practices. By far, virus-relateddiseases are not reported in African catfish.It is wise to observe the fish closely andimmediately identify abnormal behavior.Problems always have multiple causes.To distinguish the primary cause and itssolution is not easy. A good farmer shouldidentify problems before they occur.HARVEST AND TRANSPORTOF FRY AND JUVENILEDepending on the size <strong>of</strong> the catfish,advanced fry and juveniles should notbe fed 12–18 hours prior to harvesting. Athorough inspection is needed to see if thefish is healthy for selling. The fish shouldnot be disseminated if recent treatmentshave taken place. Shooters should be takenout with grader. Counting the number <strong>of</strong>fish can be based on the average weightmethod. Harvesting should be done withoutdisturbance. Customers and their transporttanks are never allowed in the farm whenharvesting. Customers are always given 2%overweight and are advised about the lastfeeding level. Responsibility stops at thefarm gate. Advanced fry should be packedin a polyethylene bag with one-third waterand two-third oxygen. Juveniles can be inopen containers. Stocking density dependson duration <strong>of</strong> transport, water temperature,oxygen or air supply, and condition <strong>of</strong> fish.THOUGHTS ABOUTCATFISH DEVELOPMENTAND PRODUCTIONIN AFRICAHATCHERYThere is great potential to establishcatfish hatcheries with various scales <strong>of</strong>production in African countries. Mediumto large hatcheries are able to pay for theinfrastructure and technological innovation.They would become centers <strong>of</strong> knowledgeand experience for other farmers. A network<strong>of</strong> hatcheries should be spread over theregions to limit transport. The development<strong>of</strong> a commercially driven catfish industryis important to ensure that hatcheries cancontinuously produce adequate and highqualityseed to supply local farmers andproducers.GROWOUT SYSTEMSThe choice <strong>of</strong> growout systems generallydepends on climate, location, level <strong>of</strong>development <strong>of</strong> regions or countries, andTable 7: Characteristics <strong>of</strong> different farming systems for African catfishPond Flow-through RASDependence on land, geology, Semidependence on land Nondependence on landsoil compositionHigh water consumption Water source, surface water Water source, bore hole(1 m 3 /kg fish), surface water or bore hole (0.4 m 3 /kg) (0.15 m 3 /kg), purificationExtensive farming: 10–15 kg/m 3 Semi-intensive farming Intensive farming(75–100 kg/m 3 ) (700–1,000 kg/m 3 )Cropping <strong>of</strong> large volume <strong>of</strong> fish Small crops Small and regular cropsStagnant waterbody with Concrete tanks or small ponds Indoor system, concrete orirregular flushing with regular flushing glass fiber tanks

78 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSscale <strong>of</strong> production. For catfish, there arethree main production systems: (1) pond,(2) flow-through and (3) indoor recirculation.Each system has its own characteristicsand management needs (Table 7). A relativecomparison among these systems (pond,flow-through and recirculation) is presentedin Table 8.FEEDSThe African catfish is a carnivorous fishwhich grows best on animal-based diets.The availability <strong>of</strong> animal proteins and fatsfor use in fishfeed in developing countriesis poor. Farmers can use locally producedcompounded feeds, imported feeds, onfarmmoist pellets or trash products (e.g.,chicken waste, maggots). The choice <strong>of</strong> feeddepends on the production system used.Feed <strong>of</strong>ten make up 70–85% <strong>of</strong> productioncost. Thus feed management (feeding, feedstorage and feed selection) is crucial forsuccess.For other technical issues in regard tograding, harvesting, hatchery maintenanceand management, the same proceduresor principles can be applied as describedabove.To recapitulate, for the conditions <strong>of</strong> Africancountries, backyard farming is accessibleto many small farmers and is an excellenttool for poverty eradication. For medium tolarge-scale investors in aquaculture, pondfarms can be very pr<strong>of</strong>itable. The RAS is onlypromising in industrial areas with perfectinfrastructure and utilities. Feed and seedproduction, quality and availability shouldbe improved to make catfish farming moresuccessful in future.Table 8: Advantages and disadvantages <strong>of</strong> pond, flow-through and RASCriteria Pond Flow-through RecirculationInfrastructure Low Moderate PerfectInvestments Low Moderate HighRunning costs Low Moderate HighLabor Less demanding Average High and skilledFeed Flexible Good quality High quality (extruded feed)Location Rural areas Rural or urban UrbanWater use High High EfficientEnvironment Uncontrolled Polluted Controlled

CATFISH NUTRITION — ASPECTS TO CONSIDER 79CATFISH NUTRITION — ASPECTS TO CONSIDERDr. S. HarpazHead, Department <strong>of</strong> AquacultureInstitute <strong>of</strong> Animal SciencesAgricultural Research OrganizationP.O. Box 6, Bet Dagan 50250ISRAELThe cost <strong>of</strong> feed usually constitutes the majorexpense in the culture <strong>of</strong> fish, comprisingabout 50% <strong>of</strong> the running costs. Therefore,any saving in the cost <strong>of</strong> feed would havea considerable impact on the pr<strong>of</strong>itability <strong>of</strong>production.There is no doubt that using high-quality feedwill lead to better growth and productionresults. Table 1 illustrates the advantages<strong>of</strong> high-quality feeds over and above thedirect growth response <strong>of</strong> the fish. Lowdigestibility <strong>of</strong> the feed will also cause watercontamination and be detrimental to fishgrowth.Unlike other farmed animals, fish requirea high level <strong>of</strong> protein in their diet andprotein is one <strong>of</strong> the most expensive dietarycomponents. Fish need a high supply <strong>of</strong>protein because they use it as a source<strong>of</strong> energy. Among the fish, carnivorestypically require higher levels <strong>of</strong> protein thanherbivores. The African catfish, althoughdefined as an omnivore is more carnivorousin nature and thus requires relatively highlevels <strong>of</strong> protein, and fat.The gross dietary protein requirement<strong>of</strong> African catfish is in the region <strong>of</strong> 40%.Table 2 shows the proximate minimumdietary requirements for catfish during thegrowout phase. The best growth rates andfeed conversion ratio (FCR) are achievedwith a diet containing between 38% and42% crude protein and an energy level <strong>of</strong>12 kJ/g. To date, the specific requirements<strong>of</strong> the African catfish for essential aminoacids, essential fatty acids, vitamins andminerals have not yet been determined.Most formulations use the levels determinedfor the channel catfish (Ictalurus punctatus).Table 2 shows the approximate minimumrequirements for this fish.There are a number <strong>of</strong> methods that canbe employed to increase food use andthus reduce production costs. Amongthese are the use <strong>of</strong> chemo-attractants andincreasing the digestibility <strong>of</strong> food throughenhancement <strong>of</strong> digestive enzyme activity.Fish (including catfish) use chemoreceptionto locate and consume their food.Replacement <strong>of</strong> fishmeal with plantmeal inthe diets <strong>of</strong> fish might lead to problems inlocating and consuming the feed. The use <strong>of</strong>various chemoattractants such as specificamino acids (see Figure 1) or betaine canalleviate this problem as well as enhancefood consumption. For the same reason,it is also important to know that when thefish are under stress they secrete mucusthat can cover their chemoreceptors andhinder their ability to locate and consumethe food.Table 1: Comparison <strong>of</strong> high- versus low-qualityfeed for catfishType <strong>of</strong> feed High quality Low quality% Protein 35-40% 7-20%Price (approx. US$) 1 per kg 0.5 per kgFeed conversion 1 : 1.0-1.2 1 : 2.0-2.5ratio (FCR)Growth rate to 5-6 months 12-14 monthsmarket sizeWater contamination Low HighPr<strong>of</strong>itability High LowTable 2: Approximate minimum dietaryrequirements for catfishFeed ingredient% inclusionDigestible energy12 kJ/gCrude protein level 40Total lipid 11Calcium 1.5Phosphorus 0.7

80 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSIncreasing the activity <strong>of</strong> the intestinalenzymes can be achieved by the addition<strong>of</strong> low levels <strong>of</strong> alcohol or salt to the diet(as has been demonstrated by Harpaz et al.1994, 2005). The salt (NaCl) is also helpfulin the absorption <strong>of</strong> the digested food sincethis activity is dependent on the Na/KATPase pump that operates better whenNa + ions are present in the intestine. Thismethod can be used for both juvenile andgrowout stages <strong>of</strong> production in which feedexpenses are highest.From the age <strong>of</strong> 1.5 months, the dietaryrequirements <strong>of</strong> African catfish do notseem to change although the feeding leveldoes need to be adjusted. At the optimaltemperature for growth (28ºC) the rationsize decreases with increasing body size(Table 3). As the fish grow larger, theirrelative consumption rates decrease fromapproximately 10% <strong>of</strong> body weight (BW)/day (at the age <strong>of</strong> 1 month) to around3-4% <strong>of</strong> BW/day (at the age <strong>of</strong> 3 monthsand above). During the growout phase, thefish should be fed at least twice a day andif possible three times a day, the quantityadministered during the first feeding largerthan the rest. The feeding level should beadjusted according to the recommendeddaily ration table (Table 3) which takes intoaccount both rearing temperature and fishsize. Providing a number <strong>of</strong> meals per dayand spreading the food (as opposed to onefeeding point) will lead to a decrease in thesize variability <strong>of</strong> the fish.APW4 L-Arg (NO 2)7 L-Alanine6 L-Alanine6 L-Arginine4 L-Alanine4 L-Arginine4 L-Arginine (NO 2) (start adapt.)7 L-Alanine6 L-Alanine6 L-Arginine4 L-Alanine4 L-Arginine6 L-Alanine6 L-ArginineFigure 1: Integrated neural responses recorded from catfish barbels following exposureto two chemo-attractants (alanine and arginine) at concentrations <strong>of</strong> 10 -4 –10 -7 MTable 3: Recommended daily rations for the African catfish, at different temperaturesand fish sizes. Feeding values (in % BW/day) based on body weight and temperature.Temp.Fish size (g)( o C) 1-10 11-25 26-50 51-100 101-300 301-80016 1.0 0.6 0.4 0.3 0.2 0.218 3.0 1.6 1.0 0.8 0.6 0.520 5.0 3.0 2.0 1.5 1.2 1.022 6.8 4.5 3.0 2.4 2.0 1.724 8.1 6.0 4.0 3.0 2.5 2.226 9.5 6.6 5.1 3.6 3.2 2.828 10.0 7.0 5.5 4.0 3.5 3.130 9.8 6.8 5.3 3.7 3.2 2.932 9.5 6.5 5.0 3.5 3.0 2.8

CATFISH NUTRITION — ASPECTS TO CONSIDER 81Least-cost diets for C. gariepinus are basedon computer-assisted formulations whichtake into account the price <strong>of</strong> differentfeed ingredients with a known nutritionalcomposition, the nutritional requirements<strong>of</strong> the fish and the cheapest combination toachieve maximal growth. In order to succeedin this task, we need to know the nutritionalvalue <strong>of</strong> the different ingredients and theirdigestibility by the fish. Research hasrevealed digestible energy values <strong>of</strong> variousfeed ingredients for Clarias gariepinus.This enables the creation <strong>of</strong> suitable feedformulations based on locally availableingredients. The results show that in catfish,the digestibility <strong>of</strong> plant-derived ingredientsis usually much lower than that from animalsources. Thus it is important to use theabove-mentioned methods to increase theactivity <strong>of</strong> the digestive enzymes leading tobetter digestibility <strong>of</strong> the feeds.BIBLIOGRAPHYBruton, M.N. 1979. The food and feeding behaviour<strong>of</strong> Clarias gariepinus (Pisces: Clariidae) in LakeSibaya, South Africa, with emphasis on its roleas a predator <strong>of</strong> cichlids. Transactions <strong>of</strong> theZoological Society <strong>of</strong> London 35(1): 47- 114.Degani, G., Y. Ben- Zvi and D. Levanon. 1989.The effect <strong>of</strong> different protein levels andtemperatures on feed utilization, growth andbody composition <strong>of</strong> Clarias gariepinus (Burchell1822). Aquaculture 76(3): 293-301.Fagbenro, D., B. Balogun, N. Ibironke and F. Fasina.1993. Nutritional value <strong>of</strong> some amphibian mealsin diets for Clarias gariepinus (Burchell 1822)(Siluriformes: Clariidae). Journal <strong>of</strong> Aquaculturein the Tropics 8(1): 95-101.Fagbenro, O. and K. Jauncey. 1994. Growth andprotein utilization by juvenile catfi sh (Clariasgariepinus) fed moist diets containing autolysedprotein from stored lactic-acid- fermentedfish-silage. Bioresource Technology 48(1):43-48.Harpaz, S. and Y. Katz. 1992. Stress related cortisollevels in channel catfi sh (Ictalurus punctatus)plasma do not affect peripheral amino acidschemoreception. Comparative Biochemistryand Physiology 102A: 459-463.Harpaz, S., A. Eshel and P. Lindner. 1994. Effect<strong>of</strong> n-propanol on the activity <strong>of</strong> intestinalproteolytic enzymes <strong>of</strong> the European sea bassDicentrarachus labrax. J. Agricult. Food Chem.42: 49-52.Harpaz, S., Y. Hakim, T. Slosman and O.T.Eroldogan. 2005. Effect <strong>of</strong> adding salt to thediet <strong>of</strong> Asian sea bass Lates calcarifer rearedin fresh or salt water re-circulating tanks, ongrowth and brush-border enzyme activity.Aquaculture 248: 315-324.Hecht, T. and S. Appelbaum. 1987. Notes on thegrowth <strong>of</strong> Israeli sharptooth catfi sh (Clariasgariepinus) during the primary nursing phase.Aquaculture 63(1): 195- 204.Hecht, T., W. Uys and P.J. Britz, Eds.1988. Theculture <strong>of</strong> sharptooth catfi sh, Clarias gariepinusin southern Africa. South African National Scientifi cProgrammes Report No. 153, 133 p.H<strong>of</strong>fman, L.C. and J.F. Prinsloo. 1995. The infl uence<strong>of</strong> different dietary lipids on the growth andbody composition <strong>of</strong> the African sharptoothcatfi sh, Clarias gariepinus (Burchell). SouthAfrican Journal <strong>of</strong> Science 91(6): 315- 320.Hogendoorn, H., J.A.J. Jansen, W.J. Koops,M.A.M. Machiels, P.H. van Ewijk and J.P. vanHees. 1983. Growth and production <strong>of</strong> theAfrican catfi sh, Clarias lazera (C. & V.). II. Effects<strong>of</strong> body weight, temperature and feeding levelin intensive tank culture. Aquaculture 34 (3/4):265-285.http://cdserver2.ru.ac.za/cd/catfi sh/catfi sh/index.htm The Biology and Culture <strong>of</strong> the AfricanCatfi sh (Clarias gariepinus). A website providingstudents at the BSc Honours and Masters levelwith a comprehensive overview <strong>of</strong> the biologyand ecology <strong>of</strong> Clarias gariepinus. Conceptualisedby T. Hecht, P. Sorgeloos, J. Verreth and F.Ollevier. Computer implementation by G. deSoete and D. Wilson.Lovell, R.T. 1984. Energy requirements. In E.H.Robinson and R.T. Lovell (eds.) Nutrition andfeeding <strong>of</strong> channel catfi sh. S. Coop. Ser. Bull.296: 12-14.Machiels, M.A.M. and A.M. Henken. 1985. Growthrate, feed utilization and energy metabolism <strong>of</strong>the African catfi sh, Clarias gariepinus (Burchell,1822), as affected by dietary protein and energycontent. Aquaculture 44(4): 271-284.Machiels, M.A.M. and A.M. Henken. 1986. Adynamic simulation model for growth <strong>of</strong> theAfrican catfish, Clarias gariepinus (Burchell1822). 1. Effect <strong>of</strong> feeding level on growth andenergy metabolism. Aquaculture 56(1): 29-52.Mgbenka, B.O. and U.L. Agua. 1990. Digestibility<strong>of</strong> some agricultural by-products by Africancatfi sh (Clarias gariepinus) Teugels 1984. Journal<strong>of</strong> Aquatic Sciences (Nigeria) 5: 15-18.

82 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSCLARIAS IN AQUACULTURE: PROS AND CONSRandall E. BrummettSenior ScientistThe WorldFish Center-CameroonHumid Forest Center, B.P. 2008 (Messa), YaoundéCAMEROONIn the past, there has been a lot <strong>of</strong> confusionabout the motivations and justifications foraquaculture. Politicians have been in thedriver’s seat, taking it upon themselves todevelop aquaculture as a means <strong>of</strong> meetingnational food security targets. Low externalinput aquaculture (LEIA) technologies havebeen promoted to diversify and stabilizesmall-scale, artisanal farming systems withsupport from governments and internationaldonors seeking to help the rural poor. Inthis approach, integrating new enterprises(e.g., aquaculture) into the farming systemincreases the efficiency <strong>of</strong> nutrient use andso improves the ecological performance <strong>of</strong>the entire farm. As a result <strong>of</strong> this approach,African aquaculture has remained within thedomain <strong>of</strong> the subsistence farm and whatexpansion there has been over the last30 years is mostly in terms <strong>of</strong> increasingnumbers <strong>of</strong> small, low productivity pondsassociated with a modest increase in fishproduction for household consumption. Ingeneral, fishfarming in Africa has done littleor nothing in terms <strong>of</strong> major and lastingcontributions to national food security andrural poverty alleviation.Letting policy drive the development <strong>of</strong> thesector, has, if you will pardon the expression,muddied the water. Politicians do not, ingeneral, grow fish and when they do, theyseldom make any genuine pr<strong>of</strong>it. In fact,fishfarmers grow fish and if you ask themwhy they grow fish, they will not mentionnational food security or poverty alleviation.They will tell you that it is to make money.So, this presentation is about how Clariascatfish can contribute to the pr<strong>of</strong>itability <strong>of</strong>aquaculture and the tools that I shall useto compare different models are based onprinciples <strong>of</strong> business planning, rather thansocial and/or ecological theory.HASSLES = LOST MONEYAn important corollary <strong>of</strong> the LEIA modelthat has caused problems for fishfarmersis the importance that has been placedon ecological complexity as the primarymeans <strong>of</strong> increasing fishpond productivity.Complicated, knowledge-intensiveintegrated systems may look good onpaper, but are <strong>of</strong>ten difficult to implement,particularly in Africa where nearly everythingis a hassle. Because much <strong>of</strong> the costassociated with land, water, labor anddepreciation are fixed, any time that afishpond is dry, understocked, underfed orotherwise not being fully utilized due to thelack <strong>of</strong> some essential input, money is beinglost. The more complicated a fishfarmingsystem and the more elements that go intothe basic production model, the more likelyare farmers to encounter costly delays.CASHFLOW VS. RETURNON INVESTMENTAnother place where development plannershave actually impeded progress is in thecalculation <strong>of</strong> what is worth doing. Becausedevelopment planners do not actuallygrow fish they tend to underestimate thedifficulties associated with managing afishfarm. In aquaculture, unlike all othertypes <strong>of</strong> animal husbandry and agriculture,the farmer cannot see what is being grownon the farm. Feed rates, size <strong>of</strong> the cropand harvest date are all approximate. Thismeans that estimation from past experience,careful planning and close monitoring areessential for success. Pr<strong>of</strong>itable commercialfishfarming is generally a fulltime affairrequiring patience, perseverance and goodbusiness sense. It is not for the disorganizedor distracted.

CLARIAS IN AQUACULTURE: PROS AND CONS 83Also, aquaculture is hard, <strong>of</strong>tenuncomfortable, work. Shoveling manure,mixing bloodmeal, pushing wheelbarrowsfull <strong>of</strong> dead fish over slippery pondbanks,getting up early in the morning, everymorning, being wet and muddy, and late fordinner are just part <strong>of</strong> the game. To justifythe amount <strong>of</strong> trouble that one unavoidablyexperiences in becoming a successfulfishfarmer, at least in the early years, pr<strong>of</strong>itshave to be significant and this implies acertain minimum scale <strong>of</strong> investment.In Cameroon, detailed farming systemanalysis has shown that properly conductedLEIA can produce about 2,500 kg/ha <strong>of</strong> fishon inputs <strong>of</strong> locally available compost. Thissystem costs the farmer very little, with cashoutlays only for fingerlings. Labor is generallycompensated with a portion <strong>of</strong> the harvest.These systems generate cash pr<strong>of</strong>its <strong>of</strong>between $50 and $300 per year (Table 1)on a total investment <strong>of</strong> $360 and $200 inrecurrent costs (either cash or in-kind). Withan attractive return on investment (ROI) <strong>of</strong>40%, many development planners wouldview this as a successful intervention onfarms that typically gross less than $500 peryear. However, considering that the farmer,instead <strong>of</strong> sitting under a tree drinking palmwine, had to dig and/or maintain a pondcarved out <strong>of</strong> muddy, snake-infested forestand chop and haul about 4 t <strong>of</strong> compostmaterials over uneven terrain, these levels<strong>of</strong> return to management are generallyconsidered inadequate even by poor farmers.The lack <strong>of</strong> enthusiasm among farmers isreflected by the inability <strong>of</strong> these small-scaleenterprises to achieve sustainability, despitea number <strong>of</strong> development projects andstartup subsidies provided by government.Now consider a production system that hasachieved sustainability (Table 2). Purchasedinputs and paid labor are used to increaseproductivity up to 3,500 kg/ha. Improvedmanagement produces three crops peryear instead <strong>of</strong> the one that can be grownon compost. Fish are grown to minimummarket size and sold. Pond surface areais increased and total investment is nowover $5,000 with recurrent costs <strong>of</strong> about$1,500. The ROI is reduced to 35%, butthe return to management is now about$2,000 on sales <strong>of</strong> 2 t <strong>of</strong> low-cost fish forlow-income consumers. In addition, thisfarmer has created at least one new job byemploying a worker, has paid other workersTable 1: Enterprise budget (in Communaute Financiere Africaine franc [XAF]) for mixed-sex Nile tilapiaLEIA production system stocked at 2 fish/m² and grown from 10 to 250 g in 360 days (US$1 = XAF500)Number Unit Total Amount Percentageper cycle price cost (XAF) <strong>of</strong> totalInvestmentAmortizationcapital(years)Pond construction (m²) 500 0 0 10 0 0.00Equipment 100,000 5 20,000 19.32StockingFingerlings (number) 1,500 25 37,500 37,500 36.23Operations (44.44)Feed (kg) 183.75 0 0 0 0.00Labor (person8-hour days) 4 1,500 6,000 6,000 5.80Transport (returntrips to market) 2 20,000 40,000 40,000 38.65Total productioncosts (per cycle) 103,500 100.00Revenues 183,750 GrossFish sales (kg) 123 1,500Productivity (kg/ha) 2,450 80,250Total Financinginvestment (% per month)183,500 0 0 Interest80,250 Net per cycleCycles per year 1 80,250 Net per yearTotal fish production 0.123 43.73 ROIper year (t)

84 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSto help dig the ponds and has generatedsignificant revenues for the hatchery, feedmanufacturer and retailers to whom thefish were sold. This scale <strong>of</strong> investment iswhat is known as a small and medium-scaleenterprise (SME) and for the purposes <strong>of</strong> thispaper will be the level at which comparisonsare made.THE SPECIFIC CASE OFCLARIASHaving reviewed some basic concepts, letus now look at how Clarias catfish, mostlygariepinus, culture fits into the definition <strong>of</strong>a successful fishfarm. Catfish, particularlyin West and Central Africa, command highmarket prices and demand among thegrowing and increasingly affluent populationwhich is generally regarded as insatiable. InCameroon for example, catfish <strong>of</strong> 300 g sellwholesale for over $4.00 per kilogram liveon the pondbank, almost twice the price<strong>of</strong> tilapia. They also grow fast and are easyto feed, reaching a minimum market size <strong>of</strong>350 g in 3 months or so, reaching nearly1 kg in 1 year.On the downside, catfish are relativelydifficult to reproduce. Despite years <strong>of</strong>research that has established relativelysimple and effective methods for inducedspawning (and even controlled naturalspawning in, for example, Egypt), larvalrearing is still a major obstacle (Yong-Sulemand Brummett 2006a, 2006b; Yong-Sulemet al. 2006a, 2006b; Yong-Sulem et al.2007). Being small, the larvae are vulnerableto a wide range <strong>of</strong> predators. Survival t<strong>of</strong>ingerling stage averages less than 30% inmost cases (Figure 1).A fundamental problem with Clarias is theirtendency towards cannibalism. Hundreds <strong>of</strong>person-hours invested in continual sorting<strong>of</strong> juveniles are required to avoid high levels<strong>of</strong> cannibalism. Stocking must be carefullycontrolled to avoid mixing fishes with toogreat a size variation.As a component <strong>of</strong> the widely promotedlow external input/small-scale artisanalfarming systems approach to aquaculture,catfish have been included as a predator intilapia-based polyculture systems aimed atincreasing the market value <strong>of</strong> the tilapias byTable 2: Enterprise budget (XAF) for mixed-sex Nile tilapia SME production system stocked at 3 fish/m²and grown from 5 to 150 g in 120 days (US$1 = XAF500)Number Unit Total Amount Percentageper cycle price cost (XAF) <strong>of</strong> totalInvestment Amortization (10.33)capital(years)Pond construction (m²) 2,000 1,000 2,000,000 10 66,667 9.39Equipment 100,000 5 6,667 0.94Stocking (21.12)Fingerlings (number) 6,000 25 150,000 150,000 21.12Operations (68.55)Feed (kg) 1,027.5 250 256,875 256,875 36.17Labor (person8-hour days) 100 1,500 150,000 150,000 21.12Transport (returntrips to market) 4 20,000 80,000 80,000 11.26Total productioncosts (per cycle) 710,208 100.00Revenues 1,027,500 GrossFish sales (kg) 685 1,500Productivity (kg/ha) 3,425 317,292Total Financinginvestment (% per month)2,736,875 0 0 Interest317,292 Net per cycleCycles per year 3 951,875 Net per yearTotal fish production 2.05 34.78 ROIper year (t)

CLARIAS IN AQUACULTURE: PROS AND CONS 85reducing their reproduction and increasingaverage size at harvest. In fishfarming theory,polyculture, the simultaneous production inthe same culture unit <strong>of</strong> multiple species withcomplementary feeding niches, has beenwidely promoted as a means <strong>of</strong> improving theefficiency <strong>of</strong> feed use, a major cost elementin fishfarming. However, as a component<strong>of</strong> a production system, polyculture clearlyfalls into the category <strong>of</strong> “hassle-prone”technology. Getting the number and quality<strong>of</strong> fingerlings <strong>of</strong> one species exactly at thetime and in the condition required is one<strong>of</strong> the major problems confronting Africanfishfarmers at all scales. Because mostfishfarms only have limited transport vehicles,holding facilities and trained staff, gettingtwo species is more than twice as difficultas getting one. In Cameroon, the basic fishproduction model being promulgated by theextension service includes three species.Little wonder then, that at any given time, anestimated 40–50% <strong>of</strong> fishponds are eithernot stocked, understocked or incorrectlystocked.The most successful catfish productionsystems that we know <strong>of</strong> are in Nigeria,mostly in the periurban zones <strong>of</strong> Lagosand Ibadan where they have easy accessto large markets. Because <strong>of</strong> high rentson land and water, systems have becomeintensive using recirculation and aerationto produce high densities <strong>of</strong> fish in tanks(Figure 2, courtesy <strong>of</strong> John Moehl, FAO).While we do not have reliable productioncost and revenue data on these farms, wecan estimate how catfish monoculture mightcompare to tilapia monoculture and tilapiacatfishpolyculture using basic principles <strong>of</strong>aquaculture business planning based onprices and on-farm growout trials conductedin Cameroon (Tables 2–5). This will give ussome idea as to how and why the Nigeriansystem has evolved in the way it has.For purposes <strong>of</strong> initial comparison, theproductive water surface area is fixed at2,000 m 2 . Water is considered as free,although initial filling and make-up water(for evaporation and other losses) are notfree in Nigeria and will not be free in most <strong>of</strong>Africa in the near future. Feed cost includeslabor used in pelleting a dried, groundand blended premix purchased from localfeedmills.Table 3 shows the results for a catfish-tilapiapolyculture <strong>of</strong> the type promoted by theCameroonian National Agricultural ResearchSystem (NARS). Tilapia are stocked at 2 fish/m 2 while catfish are stocked at 1 fish/m 2 tocontrol tilapia reproduction. Results indicatethat a fishfarm <strong>of</strong> 2,000 m 2 pond surface areacannot turn a pr<strong>of</strong>it. As the carrying capacity<strong>of</strong> tilapia is to a large extent regulated bythe ability <strong>of</strong> the pond to produce enoughoxygen to keep the fish alive and growing,the overall pond productivity is constrainedby the pond surface area. Table 4 shows howan increase in pond surface area from 2,000to 3,000 m 2 makes the farm pr<strong>of</strong>itable.Birds35.8Natural Mortality+ Cannibalism8.3Amphibians46.4Aquatic Insects9.5Figure 1: Sources <strong>of</strong> mortality for catfishfingerlings (Sulem and Brummett 2006b)Figure 2: Intensive catfish production in tanks,Nigeria

86 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSTable 3: Tilapia-catfish polyculture system (2,000 m 2 ) producing 200 g tilapia and 400 g catfish in 120 daysQuantity Unit Total Amount Percentageper cycle price cost (XAF) <strong>of</strong> totalInvestment capital Amortization (6)(years)Pond construction (m²) 2,000 1,000 2,000,000 10 66,667 5Equipment 100,000 5 6,667 1Stocking Fish/m 2 (27)Tilapia 4,000 25 100,000 2.00 100,000 8Catfish 2,000 125 250,000 1.00 250,000 19(6,000) (3.00)Operations Feed (kg/year) (68)Feed (kg) 2,300 250 575,000 1,360 575,000 44Labor (person-days) 80 3,000 240,000 960 240,000 18Transport (round trip) 4 20,000 80,000 0 80,000 6Total productioncosts (per cycle) 2,320 1,318,333 100Revenues*Productivity (kg/ha)Tilapia (kg) 402 1,500 3,371 602,328Catfish (kg) 283 2,500 2,379 708,621Productivity (kg/ha) 5,750 1,310,948 GrossCapacity anticipated 3,425 -7,385*assuming 85%survival rate tilapia;60% catfish Natural = 300 Total Financinginvestment (% per month)Compost = 2,450 3,345,000 0 0 InterestFeed = 3,425 -7,385 Net per cycleCycles per year 3 -22,155 Net per yearProduction total (t) 2.06 -1 ROITable 4: Tilapia-catfish polyculture system (3 000 m 2 ) producing 200 g tilapia and 400 g catfish in 120 daysQuantity Unit Total Amortization Amount Percentageper cycle price cost (years) (XAF) <strong>of</strong> totalInvestment capital (7)Pond construction (m²) 3,000 1,000 3,000,000 10 100,000 7Equipment 100,000 5 6,667 0Stocking Fish/m 2 (34)Tilapia 6,000 25 150,000 2.00 150,000 10Catfish 3,000 125 375,000 1.00 375,000 259,000 3.00Operations Feed (kg/year) (59)Feed (kg) 2,300 250 575,000 2,040 575,000 38Labor (person-days) 80 3,000 240,000 1,440 240,000 16Transport (round trip) 4 20,000 80,000 0 80,000 5Total productioncosts (per cycle) 3,480 1,526,667 100Revenues*Productivity (kg/ha)Tilapia (kg) 602 1,500 2,247 903,491Catfish (kg) 425 2,500 1,586 1,062,9310Productivity (kg/ha) 3,833 1,966,422 GrossCapacity anticipated 3,425 439,756*assuming 85%survival rate tilapia;60% catfish Natural = 300 Total Financinginvestment (% per month)Compost = 2,450 4,520,000 0 0 InterestFeed = 3,425 439,756 Net per cycleCycle/year 3 1,319,267 Net per yearProduction total (t) 3.08 29 ROI

CLARIAS IN AQUACULTURE: PROS AND CONS 87Table 5 illustrates the case for a catfishmonoculture. Catfish, by being able tobreathe atmospheric oxygen can be stockedat a higher rate; the final size at harvestbeing mostly dependent upon stocking andfeeding rates, that is the “intensity” <strong>of</strong> thesystem. Even though catfish fingerlings arefive times as expensive as tilapia and the foodconversion efficiency in catfish monocultureis lower (2.0 vs. 1.5 in polyculture system),the higher market value <strong>of</strong> catfish more thancompensates.CONCLUSIONDespite the hassles associated with catfishfingerling production, a comparison <strong>of</strong> tilapiamonoculture, tilapia-catfish polyculture andcatfish monoculture budgets clearly showsthe incentives that are driving fishfarmstoward more catfish-based systems. Thisis not only dependent upon the (currently)important market price differences betweentilapia and catfish, but also the physiologicalability <strong>of</strong> catfish to withstand intensification.In addition to the analysis above, theincreasingly high costs <strong>of</strong> land and water inAfrica and elsewhere mean that increasingproduction by increasing surface area underculture will become ever more expensive andimpractical. In situations where roads andcommunications are poor, close proximityto markets is essential, and land/waterprices are generally higher the closer onegets to the city and the greater the incentiveto intensify.Considering just the differences inpr<strong>of</strong>itability, fish production and reducedhassles involved in monoculture vs.polyculture, farmers in many places can beexpected to continue the shift from tilapiato catfish and from low-intensity to highintensitysystems. Taking into account thetaxable revenues generated, the number <strong>of</strong>jobs created and the amount <strong>of</strong> fish locallymarketed by the higher intensity systems,governments and development agenciesshould likewise review their emphasis on lowexternal input/artisanal aquaculture in favor<strong>of</strong> SME investments. Areas where NARScould productively invest include improvedtechnology for catfish larval rearing andselective breeding to produce catfish linesthat perform well in high-intensity culture.Table 5: Enterprise budget for Clarias production in earthen ponds and raised from 5 to 400 g in 120 daysQuantity Unit Total Amount Percentageper cycle price cost <strong>of</strong> totalInvestment capital Amortization (4.21)(years)Pond construction (m²) 2,000 1,000 2,000,000 10 66,667 3.82Equipment 100,000 5 6,667 0.38Stocking Fish/m 2 (43.02)Fingerlings (number) 6,000 125 750,000 3 750,000 43.02Operations (52.77)Feed (kg) 2,880 250 720,000 720,000 41.30Labor (person 80 1,500 120,000 120,000 6.888-hour days)Transport (round trip) 4 20,000 80,000 80,000 4.59Total productioncosts (per cycle) 1,743,333 100.00Revenues 3,240,000Fish sales (kg) 1,440 2,250Average weight (kg) 0.400 1,496,667 GrossTotal Financinginvestment (% per month)Survival rate 0.6 3,770,000 0 0 Interest1,496,667 Net per cycleCycles per year 3 4,490,000 Net per yearTotal fishproduction 4.32 119.10 ROIper annum (t)

88 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSREFERENCESYong-Sulem, S. and R.E. Brummett. 2006a.Intensity and pr<strong>of</strong>i tability <strong>of</strong> Clarias gariepinusnursing systems in Yaoundé, Cameroon.Aquacult. Res. 37: 601-605.Yong-Sulem, S. and R.E. Brummett. 2006b.Relative importance <strong>of</strong> predators in Clariasgariepinus fry mortality in Cameroon. Naga29(3,4): 74-77.Yong-Sulem, S., E.T. Tomedi, S. Mounchili, S.Tekeng, and R.E. Brummett. 2006a. Survival<strong>of</strong> Clarias gariepinus fry in earthen ponds:Effects <strong>of</strong> composts and leaks. Aquaculture260: 139-144.Yong-Sulem, S., L. Tchantchou, F. Nguefack, F.and Brummett, R.E. 2006b. Advanced nursing<strong>of</strong> Clarias gariepinus (Burchell, 1822) fi ngerlingsin earthen ponds, through recycling <strong>of</strong> tilapiarecruits. Aquaculture 256: 212-215.Yong-Sulem, S., R.E. Brummett, T.E. Tabi and J.Tchoumboué. 2007. Towards the maximumpr<strong>of</strong>i tability <strong>of</strong> smallholder catfi sh nurseries:predator defense and feeding-adapted stocking<strong>of</strong> Clarias gariepinus. Aquaculture 271: 371-376.

GENETIC IMPROVEMENT AND EFFECTIVE DISSEMINATION: KEYS TO PROSPEROUS AND SUSTAINABLE AQUACULTURE INDUSTRIES 89GENETIC IMPROVEMENT AND EFFECTIVE DISSEMINATION: KEYSTO PROSPEROUS AND SUSTAINABLE AQUACULTURE INDUSTRIESDr. Raul W. PonzoniGeneticist and Aquaculture ScientistThe WorldFish Center, P.O. Box 500 GPO,10670 Penang, MALAYSIASUMMARYThere is an increasing demand for fish inthe world due to increasing population,better economic situation in some sectors,and greater awareness about health issuesin relation to food. Since capture fisherieshave stagnated, fish farming has become avery fast growing food production system.In this presentation I give an overview <strong>of</strong> thetechnologies that are available for geneticimprovement <strong>of</strong> fish, and briefly discusstheir merits in the context <strong>of</strong> sustainabledevelopment. I also discuss the essentialpre-requisites for effective dissemination <strong>of</strong>improved stock to farmers. It is concludedthat genetic improvement programs basedon selective breeding can substantiallycontribute to sustainable fish productionsystems. Furthermore, if such geneticimprovement programs are followed up witheffective dissemination strategies they canresult in a positive impact on farmer income.INTRODUCTIONProduction systems in developing countriesare largely based on the use <strong>of</strong> unimprovedspecies and strains. As knowledgeand experience are accumulated in themanagement, feeding and animal healthissues <strong>of</strong> such production systems, theavailability <strong>of</strong> genetically more productivestock becomes imperative in order to moreeffectively use the resources. For instance,there is little point in providing ideal waterconditions and optimum feed quality to fishthat do not have the potential to grow fasterand to be harvested in time providing aproduct <strong>of</strong> the desired quality. Refinementsin the production system and improvement<strong>of</strong> the stock used must progress hand inhand.In terrestrial animal species (e.g. dairy cattle,pigs, poultry) genetic improvement programshave made a substantial contribution toindustry productivity and viability. The gainsachieved among plants species have beeneven more spectacular. There appears to begreat potential for improvement in aquaticanimal species, given that comparativelylittle application <strong>of</strong> genetic improvementtechnology has taken place to date. Hence,there is ample justification for the planning,design and implementation <strong>of</strong> research,development and technology transfer <strong>of</strong>genetic improvement programs for aquaticspecies.Such programs are particularly well-suitedto contribute towards the fulfillment <strong>of</strong> nobleaims, such as increasing the amount <strong>of</strong>animal protein available to greater numbers<strong>of</strong> people in developing countries, thusassisting in achieving greater food security.Furthermore, they can do so in a sustainablemanner, and without having undesirableenvironmental repercussions. In this paper Igive an overview <strong>of</strong> the technologies that areavailable for genetic improvement <strong>of</strong> fish, andI also discuss the essential pre-requisites foreffective dissemination <strong>of</strong> improved stock t<strong>of</strong>armers.BACKGROUND AGAINST WHICHGENETIC IMPROVEMENTPROGRAMS OPERATEAn ever-increasing human population, bettereconomic situation in some sectors, andgreater awareness about the health issuesin relation to food, have resulted in a greaterdemand for fish in the world. Since capturefisheries have stagnated, fish farming hasbecome a very fast growing food productionsystem.

90 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSFISH GENETIC IMPROVEMENTCAN HELP ACHIEVESUSTAINABLE GAINSGenetic improvement programs have thefollowing highly desirable attributes:1.2.3.4.5.6.Power to modify the animal to suit apurpose or environment.Greater food security and povertyalleviation by increasing productivity,reliability and consistency – and thegain may be permanent.Solutions to existing or emergingpathogens and to environmentalchallenges.Favorable return on investment.Help in filling the gap between demandand supply without a negativeenvironmental impact.Assistance in managing inbreeding inthe production system.Genetic improvement programs for fishcan contribute towards the productionsystem’s output, both in quantitative andqualitative terms, by enhancing traits <strong>of</strong>major importance, such as:• Growth rate to harvest weight or date• Survival• Stress and disease resistance• Cold water tolerance• Sexual maturation• Product quality• Feed efficiencyThe emphasis placed upon these traitswill depend on a number <strong>of</strong> factors. Forinstance, the phase <strong>of</strong> the improvementprogram, specific circumstances in terms<strong>of</strong> diseases and environmental challenge,and so on. Typically, a considerable amount<strong>of</strong> effort is devoted to the improvement <strong>of</strong>growth rate. This is justified, as <strong>of</strong>ten, thereare clear advantages in producing largerfish in a given period <strong>of</strong> time, or fish <strong>of</strong> aparticular size in a shorter grow-out period.The question then is, how can we improvethese traits?STEPS IN THE DESIGNOF A GENETICIMPROVEMENT PROGRAMGENERALFrom the WorldFish Center we are attemptingto approach work in this area in a logicaland systematic manner, by addressing, asdeemed appropriate in each circumstance,all the activities that the planning, designand conduct <strong>of</strong> a genetic improvementprogram entail, namely:1.2.3.4.5.6.7.8.Description or development <strong>of</strong> theproduction system(s)Choice <strong>of</strong> the species, strain(s) andbreeding systemFormulation <strong>of</strong> the breeding objectiveDevelopment <strong>of</strong> selection criteriaDesign <strong>of</strong> system <strong>of</strong> genetic evaluationSelection <strong>of</strong> animals and <strong>of</strong> matingsystemDesign <strong>of</strong> system for expansion anddissemination <strong>of</strong> the improved stockMonitoring and comparison <strong>of</strong>alternative programsGenerally these steps would be taken in thisorder, but not always necessarily so. Therewill always be iterations, going back to earliersteps, making modifications, and rectifyingcourses <strong>of</strong> action. Note that attention toall aspects is essential for the conductand implementation <strong>of</strong> an effective geneticimprovement program. An example <strong>of</strong> theuse <strong>of</strong> the approach suggested in this papermay be found in Ponzoni (1992), which alsoprovides references on the methodologythat may be used. I will now briefly treateach one <strong>of</strong> the above listed steps, withspecial reference to the improvement <strong>of</strong>aquatic animal species.BRIEF TREATMENT OF EACHSTEP1. DESCRIPTION OF THE PRODUCTIONSYSTEM(S)Before even thinking about geneticimprovement we have to be clear aboutthe range <strong>of</strong> production systems for whichgenetic improvement is intended. This stepentails specifications such as:

GENETIC IMPROVEMENT AND EFFECTIVE DISSEMINATION: KEYS TO PROSPEROUS AND SUSTAINABLE AQUACULTURE INDUSTRIES 91(i) Nature <strong>of</strong> the production system (e.g.mono or poly-culture, smallholder,commercial operation, industrialoperation)(ii) Feeding regime(iii) Environmental challenge (disease,temperature, water quality)(iv) Sex and age (or size) <strong>of</strong> harvestedindividuals(v) Social environmentTo a large extent these issues have beenaddressed in current projects. There couldbe opportunities, however, in re-examiningthe range <strong>of</strong> production systems for whichgenetic improvement is intended, and, inparticular, anticipating likely developmentsand possible future production systems.Identifying major production systems is veryimportant, because it may be that thereis no single ‘genotype’ that is ‘best’ in allproduction environments (i.e., presence <strong>of</strong>species or strain by environment interaction).If genotype by environment interactionsare suspected (or in fact do exist), treatingthe expression <strong>of</strong> the trait(s) in question indifferent environments as different traits andestimating the genetic correlation betweenboth expressions will be informative.2. CHOICE OF THE SPECIES, STRAIN(S)AND BREEDING SYSTEMThe decisions on choice <strong>of</strong> species andstrain sometimes are partly made for us,as when there are limitations on availability<strong>of</strong> stock, or well defined local preferences.However, when possible, making the rightchoice is important because the gainachieved in this way may be equivalent toseveral generations <strong>of</strong> selection.The choice <strong>of</strong> species and strains shouldpreferably be made on the basis <strong>of</strong>information derived from well-designedexperiments on species and straincomparison, and estimation <strong>of</strong> phenotypicand genetic parameters (heterosis,heritability, correlations among traits,genotype by environment interactions).Such experiments can be complex andcostly, but they are very necessary. TheGIFT (Genetic Improvement <strong>of</strong> FarmedTilapia) approach used for tilapia (andsuggested also for carp) is a sound way <strong>of</strong>addressing the issue. There could be roomfor refinements <strong>of</strong> design in some cases, andin-depth analysis <strong>of</strong> presently available andfuture data should be conducted. Greateraccuracy in our estimates <strong>of</strong> phenotypicand genetic parameters can result in greatereffectiveness <strong>of</strong> the genetic improvementprograms.Looking for genes <strong>of</strong> relatively large effecton traits <strong>of</strong> relevance for the productionsystem(s) by statistical procedures in the datacollected could yield valuable results. If anywere found they could become candidatesfor gene mapping and expression studies.3. FORMULATION OF THE BREEDINGOBJECTIVEThe formulation <strong>of</strong> the breeding objectiveis crucial because it determines ‘where togo’ with the genetic improvement program.The breeding objective is intimately relatedto the production system. We have to makesure that the trait(s) we improve are those <strong>of</strong>importance in the actual production system.Generally these will be the traits that impactupon income or expense in the productionsystem, or those associated with benefitsto the user <strong>of</strong> the improved animals in anon-cash economy, or those that influencesociological preference.There are two main ways <strong>of</strong> defining thebreeding objective:(i) As a statement <strong>of</strong> intent <strong>of</strong> desiredgenetic gain in each trait(ii) From a mathematical function describingthe production system, deriving aneconomic value for each traitThe breeding objective usually includes traitssuch as: growth rate or size, survival rate,age at sexual maturity, disease resistance,tolerance to water temperature or toother water attributes, flesh quality, feedconversion. Of these, growth rate (or size ata particular age) has been the most popular,partly because its impact is easily perceivedand it can be measured. There are risks,however, in over-simplifying the breedingobjective to a single trait, as unfavorablecorrelated responses can occur. Even if not

92 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSformally included in the breeding objective,traits perceived as being <strong>of</strong> importance inthe production system should be carefullymonitored.The issue <strong>of</strong> breeding objectives has beenaddressed only to a limited extent in someprojects. This may be justified by the overridingimportance <strong>of</strong> size or growth rate.However, there will <strong>of</strong>ten be opportunity torefine improvement programs through workon breeding objectives, as these evolve. Forinstance, new traits may have to be formallyincorporated as the production systemdevelops, or in response to changingconsumer demands. When there is a needfor radically different traits, or for very fastimprovement beyond what is possible withconventional methods, genetic engineeringand the creation <strong>of</strong> transgenic animals havebeen proposed as options. However, thecost <strong>of</strong> implementing such options, andthe (<strong>of</strong>ten found lack <strong>of</strong>) acceptability byconsumers <strong>of</strong> the animals thus created havegiven rise to considerable controversy, andshould be critically assessed before beingproposed as an alternative.4. DEVELOPMENT OF SELECTIONCRITERIAThe selection criteria are characters closelyrelated, but not necessarily identical, tothe traits in the breeding objective. Thebreeding objective is about ‘where to go’with the genetic improvement program,whereas the selection criteria are about‘how to get there’. The selection criteria arethe characters we use in the estimation <strong>of</strong>breeding values and overall genetic merit <strong>of</strong>the animals.Selection criteria may be different from thetraits in the breeding objective. For instance,we may be interested in increasing marketweight, but we may base our selectionon weights taken at an earlier age, beforereaching market weight, in an attempt tospeed up the selection process by choosingbreeding animals earlier. Also, there may becases in which we do not select directlyfor the trait in the breeding objective, butwe use an indicator character instead (e.g.length <strong>of</strong> fish could be used as an indicator<strong>of</strong> weight).The characters used as selection criteria arelinked to the traits in the breeding objectivevia genetic variances and covariances.Hence the need for phenotypic and geneticparameters in the estimation <strong>of</strong> breedingvalues for relevant traits.There may be new developments throughgene mapping and marker assisted selection(MAS). There are some traits that can haveimportance in the breeding objective but aredifficult to measure. Disease resistance andtolerance to some environmental challengesare examples. For such traits ‘conventional’selection procedures based on quantitativegenetics sometimes have limitations, anddevelopments in the area <strong>of</strong> MAS could bevaluable.Note that even if we concluded thatcrossbreeding was the best alternative asa breeding strategy, we would still have toconsider within breed or strain selection,and the above discussion on selectioncriteria would be appropriate.The notion <strong>of</strong> separately dealing with traitsin the breeding objective and charactersused as selection criteria can be <strong>of</strong> help inbringing some <strong>of</strong> the current and likely futurework into sharper focus (e.g. place MAS inproper context and perspective in relationto genetic improvement work as a whole).5. DESIGN OF GENETIC EVALUATIONSYSTEMAssume that the production and breedingsystem, the breeding objective and theselection criteria have already beenestablished. The environment for selectionshould be as close as possible to theproduction environment, unless there isvery clear evidence <strong>of</strong> absence <strong>of</strong> genotypeby environment interactions.The genetic evaluation system can vary fromsomething very simple, involving just massselection for one or a few traits, to somethingmuch more complex, involving fitting ananimal model to the data, or separate sibor progeny testing for specific traits (e.g.disease after challenge, flesh quality afterslaughter). Depending on our ability toidentify individuals and to keep track <strong>of</strong>pedigrees we may use mass selection,

GENETIC IMPROVEMENT AND EFFECTIVE DISSEMINATION: KEYS TO PROSPEROUS AND SUSTAINABLE AQUACULTURE INDUSTRIES 93family selection, or, best <strong>of</strong> all, BLUP (bestlinear unbiased prediction) breeding valuescombining the available information. Withthe very high reproductive rate <strong>of</strong> fish andthe relatively low cost per individual, whendeemed necessary, it should be possible toset up families for specific purposes, suchas, evaluating for disease resistance or forflesh quality.The area <strong>of</strong> individual identification (uniqueand at an early age) <strong>of</strong> animals and theirparents is one likely to impact on the geneticevaluation system adopted. Developmentsin DNA technology (DNA fingerprinting)could be <strong>of</strong> great assistance. This could bean area worthy <strong>of</strong> consideration in futureresearch and development proposals.6. SELECTION OF ANIMALS AND OFMATING SYSTEMIdeally we would only reproduce the‘best’ individuals. In practice we need acompromise between selection intensity andeffective population size in order to managerisk (inbreeding). The increase in inbreedingis proportional to 1/2Ne, where Ne is theeffective population size. A relatively largeNe is required to:(i) Sustain genetic variation in thepopulation in the long term(ii) Manage inbreeding(iii) Increase the selection limit(iv) Have predictable responses toselectionFor situations where mass selectionis used, Bentsen and Olesen (2002)suggest a minimum <strong>of</strong> 50 pairs to maintainapproximately a 1% increase in inbreedingper generation. With full pedigreeinformation inbreeding can be managedmore effectively, avoiding matings <strong>of</strong> closelyrelated individuals. When full pedigrees arenot an option, sub-dividing the populationcan help, so that animals can be selectedfrom the various sub-populations.An aspect that may be worth considering isthe establishment <strong>of</strong> one or more replicates<strong>of</strong> the selected population for securityreasons, in case it was destroyed by diseaseor some other disaster.7. DESIGN OF SYSTEM FOREXPANSIONGenetic improvement typically takes placein a very small fraction <strong>of</strong> the population.The genetic improvement achieved in that‘elite’ <strong>of</strong> superior animals is multiplied anddisseminated to the production systems.The flow <strong>of</strong> genes is graphically illustratedin Figure 1.Flow <strong>of</strong> genesSelection (breeding center)Multiplication (hatcheries)Production systemFigure 1: Flow <strong>of</strong> genes from the breeding centerto the production systemFish are very well placed with their highreproductive efficiency, to develop costeffectivestructures for the dissemination<strong>of</strong> genetic gain. The implementation <strong>of</strong> thegenetic improvement program in a relativelysmall number <strong>of</strong> animals can be enough toservice a very large population involved inproduction.Unfortunately, experience shows that whena successful strain and market for such astrain develop, malpractice <strong>of</strong>ten proliferates,facilitated by the very high reproductive rate<strong>of</strong> fishes, and stock quality deteriorates asa consequence <strong>of</strong> inbreeding and smallpopulation size. There is no simple wayout <strong>of</strong> this, except perhaps through thecreation <strong>of</strong> a formal structure that is not onlytechnically sound but also regulates theprocess and enables the implementation<strong>of</strong> quality assurance practices. Box 1illustrates in a diagrammatic form importantconsiderations that should be made whenplanning and putting in place a logicallybased system for the dissemination <strong>of</strong>improved stock <strong>of</strong> aquatic species.Note that in designing the system forexpansion, the characteristics <strong>of</strong> theproduction system have to be taken intoconsideration again. For instance, if singlesex or infertile populations are preferablefor production, we may need hormonaltreatment in the production system, or

94 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSchromosome manipulations (e.g. creation <strong>of</strong>YY males) in the multiplication phase. Thelag created by additional generations beforethe animals reach the production phase alsohas to be taken into consideration.The relative sizes <strong>of</strong> the population sectorsinvolved in selection, multiplication andproduction should be examined and madeconsistent with an effective transfer <strong>of</strong>genetic gain to the production sector.8. MONITORING AND COMPARISON OFALTERNATIVE PROGRAMSMonitoring the genetic improvementprogram is important to ensure that theanticipated genetic gain is actually beingachieved. Of course, if it is not, action hasto be taken to rectify the situation.Box 1: Considerations to be made during theplanning and putting in place <strong>of</strong> a formalscheme for the dissemination <strong>of</strong> improvedstock from breeding centers to fish farmersThere are options, but we have to consider… The resources available• Staff• Facilities• Capital• Operating locations Competence or access to it Size and other characteristics <strong>of</strong> the industry tobe serviced Industry level in terms <strong>of</strong> technology applicationand education <strong>of</strong> membersOptions for multiplication Through government stations (<strong>of</strong>ten limited intheir impact) With participation <strong>of</strong> private operators• Joint ventures• Licensing <strong>of</strong> hatcheries• Contracted production• Sale <strong>of</strong> breeders to hatcheries with fewconditions• Combinations <strong>of</strong> the aboveCreation <strong>of</strong> a network <strong>of</strong> hatcheries Terms <strong>of</strong> the agreement• Financial• Operational Training and education <strong>of</strong> hatchery managers A brand name for successful marketing Product standards• Fingerling size and survival• Transport and count accounting• Management <strong>of</strong> inbreeding• Breeders’ age (lag)• Lag and options for refreshing Genetic piracyGenetic gain can be measured in a number<strong>of</strong> different ways. The establishment <strong>of</strong>randomly selected populations is a usefulway, particularly when the visual impactcreated by the comparison <strong>of</strong> the ‘selected’vs. ‘unselected’ populations is consideredimportant in increasing adoption or credibility<strong>of</strong> results. However, the maintenance <strong>of</strong>control populations requires funds andeffort.When visual impact is not a high priority,instead <strong>of</strong> establishing control populations,genetic gain may be estimated usingappropriate statistical procedures that relyon the presence <strong>of</strong> genetic links betweengenerations. These genetic links enable theestimation <strong>of</strong> genetic and environmentaltrends over time. This is an option that couldbe explored in current and future projects.There will <strong>of</strong>ten be sensible alternatives inprogram steps 1 to 7. Generally, testingall <strong>of</strong> such alternatives in the field willnot be possible, but we could conducttheoretical and numerical work to predictlikely outcomes. For instance, we may beinterested in assessing the consequences<strong>of</strong> including or ignoring a particular traitin the breeding objective, or in comparingthe merit <strong>of</strong> a single breeding objectivein a range <strong>of</strong> production systems, or inevaluating particular sources <strong>of</strong> informationas selection criteria in the genetic evaluation<strong>of</strong> animals. At present there appears to beno work along these lines, but this is an areaworthy <strong>of</strong> consideration in future planning.Sometimes this type <strong>of</strong> work helps uncoveropportunities to increase the effectiveness<strong>of</strong> the genetic improvement program, or <strong>of</strong>saving costs and effort.WHAT SORT OF RESPONSE CANSELECTIVE BREEDING ACHIEVE?Provided there is: (1) abundant geneticvariation in the base population; (2) selectionfor a well-defined, heritable trait(s); and(3) maintenance <strong>of</strong> genetic variation bycontrolling inbreeding and avoiding smallpopulation sizes, we can then expectgenetic gains as shown in Table 1. Figure2 graphically shows the gain in growth rateexperienced in the case <strong>of</strong> GIFT fish.

GENETIC IMPROVEMENT AND EFFECTIVE DISSEMINATION: KEYS TO PROSPEROUS AND SUSTAINABLE AQUACULTURE INDUSTRIES 95CONCLUDING REMARKSSelective breeding is a genetic technologythat can provide continuous improvement<strong>of</strong> a fish population. Other technologies(e.g. gynogenesis, hybridization, triploids)should not be looked upon as alternatives,but as supplementary to selective breeding.The genetic improvement proceduresrecommended and implemented bythe WorldFish Center utilize naturallyoccurring genetic variation. In otherwisesustainable aquaculture systems, selectivebreeding <strong>of</strong>fers great opportunities withoutundesirable side effects. A number <strong>of</strong>successful examples exist. Furthermore, ifTable 1: Realized responses to selection in growthrate in three species <strong>of</strong> fishSpecies Gain per Number <strong>of</strong>generation % generationsAtlantic salmon 12.0 6Nile tilapia (GIFT) 15.0 5Rohu carp 17.0 3such genetic improvement programs arefollowed up with effective disseminationstrategies they can result in a highly positiveimpact on farmer income.In the short- and medium-term aquaculturegenetic improvement programs will bebest served by judicious use <strong>of</strong> proventechnology (i.e. based on quantitativegenetics), and gradual incorporation <strong>of</strong>new technologies (e.g. MAS), as evidenceon their usefulness becomes available fromresearch, development and validation.REFERENCESBentsen, H. and Olesen, I. 2002. Designingaquaculture mass selection programs to avoidhigh inbreeding rates. Aquaculture 204:349-359.Ponzoni, R.W. 1992. Genetic improvement <strong>of</strong>hair sheep. FAO Animal Production andHealth, Paper no. 101, 168 p. (Rome,Italy).Accumulated selection responseGrowth performance+85%Base1 2 3 4 5Figure 2: Genetic gain in GIFT fish over five generationsGeneration<strong>of</strong> selection

96 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSGENETIC IMPROVEMENT OF CLARIAS GARIEPINUS ATTHE WORLDFISH CENTER, ABBASSA, EGYPTMahmoud A. RezkAquaculture ScientistThe WorldFish Center-EgyptAbbassa Research Center, Abbassa, Abou-Hammad, SharkiaEGYPTINTRODUCTIONFish production is viewed as an importanttool to close the gap between supplyand demand for animal protein in Egypt.Production from natural fisheries is estimatedto be at a maximum sustainable level. Overa 10-year period, 1996–2005, total captureincreased from 340,434 to 349,553 tonnesFish farming is the only available meansto achieve a significant improvement infish production. The aquaculture systemin Egypt is largely dependent on Niletilapia, Oreochromis niloticus, with smallercontributions from mullets, carps and Clariidcatfishes to total production.Production <strong>of</strong> African catfish, Clariasgariepinus, so far, is mainly from capturefisheries. Use <strong>of</strong> the species for farminghas encountered a number <strong>of</strong> obstaclesincluding problems with reproductionand fry maintenance, and poor reputationamong customers based mainly on itsnatural feeding habit as a scavenger.Establishment <strong>of</strong> catfish as anothermajor aquaculture species should help indiversifying aquaculture production andavoiding the drawbacks <strong>of</strong> a system that islargely based on a single species. Africancatfish is endemic to all freshwater bodiesin Egypt. The potential for its use in Egyptianaquaculture is very high because <strong>of</strong> severalfactors related to the aquaculture system, thespecies itself and existing market forces.African catfish has several biologicaltraits that make it a suitable species foraquaculture. Fish reach sexual maturitywithin the second year <strong>of</strong> their life, feed lowon the food web, reach market size withinthe first season <strong>of</strong> growth and tolerate harshenvironmental conditions. They are alsosuitable for polyculture, highly acceptable onthe market and can survive for several hourseven outside the water which minimizes theirtransportation requirements to the market.Little has been done to improve aquacultureperformance <strong>of</strong> African catfish. Therefore,the potential for genetic improvement <strong>of</strong>the species is very high. Research andapplications using hybridization (Legendreet al. 1992; Nwadukwe 1995; Senanan et al.2004); gynogenesis and androgenesis (na-Nakorn et al. 1993; Bongers et al. 1995);cytogenetics (Teugels et al. 1992; Nagpureet al. 2000a, 2000b); and biochemical andmolecular markers (Agnese and Teugels2001; Sukmanomon et al. 2003; Poompuangand na-Nakorn 2004; Senanan et al. 2004;Islam et al. 2007) were accomplished. TheWorldFish Center is carrying out the world’sfirst genetic improvement project <strong>of</strong> Clariasgariepinus that uses selective breedingtechnology. In this paper, the variousaspects <strong>of</strong> this project will be discussed.EXPLORATORYINVESTIGATIONSThe beginning <strong>of</strong> the project was a thoroughassessment <strong>of</strong> the current state <strong>of</strong> knowledgeconcerning the biology and potential foreconomic production <strong>of</strong> African catfish.While limited knowledge <strong>of</strong> the basic biologyand fishfarming requirements <strong>of</strong> the speciesexist, further information was needed tosupport the initiation <strong>of</strong> a selective breedingprogram. Most <strong>of</strong> the available informationis concerned with mass spawning andreproduction, bulk rearing <strong>of</strong> resulting fry,and fishfarm use <strong>of</strong> Clarias, mostly as a

GENETIC IMPROVEMENT OF CLARIAS GARIEPINUS AT THE WORLDFISH CENTER, ABBASSA, EGYPT 97means to control reproduction and suppressunwanted fish population in the fishfarm.Proper and elaborate selective breedingprograms require complete separation <strong>of</strong>spawns, identification <strong>of</strong> full-sib groups andtheir relationship with other individuals in thepopulation, spawning dates <strong>of</strong> each fish andimpact <strong>of</strong> rearing environments at differentstages <strong>of</strong> life on performance <strong>of</strong> individualfish and families. This justifies the need fora reliable method for the identification <strong>of</strong>individual fish throughout the experimentalperiod and keeping accurate records onancestry and performance <strong>of</strong> all individualsfrom one generation to the next.Production <strong>of</strong> families in isolation and theirtagging necessitated conducting severalexperiments to identify new techniquesand to solve specific problems with othersconcerning:1. Achievement <strong>of</strong> pairwise reproductiona. success <strong>of</strong> pairwise spawning inhapasb. choice <strong>of</strong> suitable hapa materialc. success <strong>of</strong> paternal second spawning2. Separate rearing <strong>of</strong> families until tagginga. rearing environmentsb. water qualityc. cannibalism among fryd. stocking densitye. feeding3. Tagginga. suitable age and size for taggingb. type <strong>of</strong> tagc. tagging techniqued. use <strong>of</strong> anesthesiae. tag loss at stockingf. tag loss until harvestThe purposes <strong>of</strong> this exploratory study wereto:1.2.3.gain a better understanding and controlon the reproduction <strong>of</strong> African catfish,Clarias gariepinus, stocks obtainedfrom different geographical locationsand crosses between them;be able to reliably rear and tag theresulting fry;close the life cycle under conditionsrequired for practical selective breeding;and4.identify potential problems associatedwith the above-mentioned activitiesand possible solutions.COLLECTION OFBROODFISHCommunications with potential providers<strong>of</strong> broodfish were established in spring<strong>of</strong> 2004. Arrangements were made totransfer broodfish in August 2004 from theoriginal locations to the research station atAbbassa. Clarias broodfish were collectedfrom Abbassa, Kafr El Sheikh and Fayoum.The Fayoum stock was originally collectedfrom Rasheed on the Mediterranean coast(Figure 1). Subsequently another stock wasobtained from Al Kanaes, Beheira, in thesummer <strong>of</strong> 2005. The numbers <strong>of</strong> individualsobtained from each <strong>of</strong> the locations areshown in Table 1. Provision <strong>of</strong> matureClarias as a source <strong>of</strong> pituitary glands foruse in stimulation <strong>of</strong> spawning was arrangedfrom the production ponds at the Abbassaexperimental station.SPAWNING AND FRYPRODUCTIONAfter collection <strong>of</strong> Clarias gariepinus stocks,each <strong>of</strong> them was maintained separatelyin a 200 m 2 concrete-walled pond. Matingarrangements were made in anotherearthen pond that had nylon netting hapas,125×80×100 cm (length×width×depth)installed inside external cotton cloth hapasthat were used to prevent escape and mixup<strong>of</strong> fry from different families and to assessthe possibility <strong>of</strong> the very fine hatchlingsTable 1: Number <strong>of</strong> male and female Clariasgariepinus obtained from different locations withinEgypt for use in the study <strong>of</strong> reproductive biologyand the subsequent initiation <strong>of</strong> a geneticimprovement program for increased body weightStock Female MaleAbbassa 85 35Kafr El Sheikh 44 25Beheira* 58 32Rasheed 52 33Total 239 125* This was the last stock that was obtained in summer <strong>of</strong>2005. It was not included in the initial trials conducted in2004 although it was included in the selection program in2005.

98 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSpassing through the mesh <strong>of</strong> the internalnylon netting hapas once they hatch andswim up (Figure 2).Females were checked for readiness tospawn. Ready-to-spawn (mature) femaleswere identified based on their secondarysexual characteristics and the release <strong>of</strong>ripe eggs on gentle pressure applied to thelower part <strong>of</strong> the abdomen (Figure 3). Thoseexpected to be mature or close to maturitywere selected, weighed and assigned to thebreeding hapas.A male <strong>of</strong> matching weight was paired witheach female in a separate hapa on 15 August2004. The top <strong>of</strong> the hapa was closed bystitching to prevent fish from jumping out.Water temperature throughout the spawningperiod varied between 26ºC and 30ºC.Fluctuation <strong>of</strong> temperature was limited bythe size <strong>of</strong> the pond (2,000 m 2 ) where thetrial was conducted. Hapas were inspectedfor spawning on 16 August. Pairs that didnot spawn were allowed another 24 hoursand inspected again. Pairing combinationsand number <strong>of</strong> spawns obtained in eachcombination are shown in Table 2. Only oneFigure 1: Map <strong>of</strong> northern Egypt showing the locations () where African catfish, Clarias gariepinus,broodfish were collected

GENETIC IMPROVEMENT OF CLARIAS GARIEPINUS AT THE WORLDFISH CENTER, ABBASSA, EGYPT 99additional incidence <strong>of</strong> spawning occurredon 17 August. Further extension <strong>of</strong> thespawning period was associated with adrastic increase in number and severity <strong>of</strong>Figure 2: Spawning hapas (green) with outer clothhapas (white); the top <strong>of</strong> the spawning hapas wasstitched to prevent escape <strong>of</strong> broodfishinjuries, fin erosions and even mortality <strong>of</strong>broodfish, but not spawning.Spawning usually took place during the night.Sticky eggs were found scattered all over thebottom and the walls <strong>of</strong> the inner hapa in thenext morning. Broodfish were removed anda sample <strong>of</strong> eggs was collected (Figure 4)and checked for occurrence <strong>of</strong> fertilization.Broodfish were removed from the hapas andmales were saved for use in a second spawnthat was attempted 1 and 2 weeks after thefirst spawn. Hatching was observed on thefollowing day. Females obtained from KafrEl Sheikh were the latest to be introducedto the research station and were expectedto exhibit poor maturation and spawningsuccess. A total <strong>of</strong> 31 females spawned, 30<strong>of</strong> which produced fry out <strong>of</strong> 40 females thatwere identified as ready to spawn and 20that were identified as less ready. Of the 31spawns, 29 were obtained from the readyto-spawngroup while 2 came from the lessreadyfemales. This observation signifiesthe importance <strong>of</strong> accurate broodstockselection by experienced personnel fornatural spawning.Figure 3: The lower abdomen and the genital area<strong>of</strong> a gravid female catfish are shown; release <strong>of</strong>ripe eggs signals the female’s readiness forspawningFigure 4: Fertilized catfish eggs collected fromthe bottom <strong>of</strong> the spawning hapaTable 2: Number <strong>of</strong> spawns/number <strong>of</strong> pairs used in the initial trials <strong>of</strong> reproduction indifferent mating combinations between stocks <strong>of</strong> Clarias gariepinus collected fromdifferent geographical locations within EgyptFemalesMale spawningMales Abbassa Kafr El Sheikh Rasheed occurrence/lineAbbassa 4/4 3/5 4/5 11/14Kafr El Sheikh 3/4 2/4 5/7 10/15Rasheed 3/3 2/4 4/4 9/11Total spawning/line 10/11 7/13 13/16 30/40

100 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSMales that reproduced successfully inmid-August were used in a trial towardproducing a second spawn with newunspawned females. Spawning successwas evaluated 1 and 2 weeks after the firstspawn. Success level was very limited. Only4 spawns were produced from the 30 pairsthat were allowed to mate. Out <strong>of</strong> the 4spawns, there was 1 spawn that producedfry. The other 3 spawns did not produce anyfry. Another attempt was conducted 1 weeklater with the use <strong>of</strong> catfish pituitary extract(CFPE) injections to enhance spawning.No spawns were obtained but a drop inwater temperature (22–26ºC) during thatperiod may have contributed to the lack <strong>of</strong>reproductive activity.Several attempts were conducted toaccomplish a second spawn in hapasinstalled in heated and covered concretetanks. Different levels <strong>of</strong> CFPE were usedto enhance spawning in both malesand females. Again, no spawning wasobserved.The trial indicated the following:1.2.3.Reproduction can be accomplishedwhile maintaining the integrity <strong>of</strong> full-sibfamilies.Crossing between strains can beaccomplished successfully.Reproductive isolating mechanisms donot appear to be a problem accordingto the trial that was conducted.Production <strong>of</strong> a second spawn was notsuccessful, possibly because <strong>of</strong>unfavorable temperature. This wasattempted again in 2005 and producedpositive results.FRY REARINGIn spite <strong>of</strong> the fine-mesh size <strong>of</strong> the spawninghapas, a small number <strong>of</strong> sac fry passedthrough the mesh in several <strong>of</strong> the innerhapas indicating that fry size upon hatchingis marginal to the mesh size <strong>of</strong> the materialthat was used. At the same time, it was feltthat using smaller mesh size might causeproblems because <strong>of</strong> its effect on foulingand the anticipated problems with waterexchange which might in turn have an effecton fry health and survival. Individuals thatwere found in the outer, cloth hapa werecollected on the third day and placed backwith their full-sibs inside their respectiveinner hapas at which time they were largeenough to remain inside the mesh hapas.No fry were observed in the outer hapalater. The outer hapa was then removed andfry were kept in the mesh hapa until the end<strong>of</strong> the first week after hatching (Figure 5).The resulting fry were then counted and frynumbers per family were standardized at300 fry per family.Fry were then reared in the hapas for 2weeks. Rapid growth was noted up to anaverage <strong>of</strong> 0.5–1.0 g but then slowed down.A drastic decrease in the number <strong>of</strong> fryper family was noted during sampling. Anotable divergence <strong>of</strong> the size <strong>of</strong> fry wasalso observed (Figure 6). The loss <strong>of</strong> frywas suspected to affect growth rates indifferent families. The reason for the losswas unclear at this stage but cannibalismwithin the full-sib families was suspected asa possible reason. Accordingly, two trialsFigure 5: Swim up fry, 4 days old, in the spawninghapasFigure 6: Size variation within a single full-sibgroup <strong>of</strong> Clarias gariepinus

GENETIC IMPROVEMENT OF CLARIAS GARIEPINUS AT THE WORLDFISH CENTER, ABBASSA, EGYPT 101were set up to explore certain aspects <strong>of</strong>rearing techniques that may help in growinga reasonable number <strong>of</strong> fry to a size/weightthat is suitable for PIT (Passive IntegratedTransponder) and Floy tagging. One trialwas conducted to investigate growth ratesin hapas at different stocking densities. Theother was conducted to explore the impact<strong>of</strong> cannibalism on fry loss.FRY GROWTHBecause <strong>of</strong> the divergence in fry sizes withineach full-sib group, fry were sorted by sizeinto two groups, large and small. Large fry,jumpers, were saved while small fry, whichrepresented the majority <strong>of</strong> the fry in eachhapa, were used in this experiment. Fry fromdifferent hapas were not mixed becausewe were mainly interested in identifyingconditions that would lead to all, or most,<strong>of</strong> the families reaching tagging size withina suitable timeframe (e.g., 2 months). A set<strong>of</strong> two hapas, 1 m 3 and 6 m 3 , was installedfor each <strong>of</strong> the fry hapas. Two subgroups <strong>of</strong>50 and 60 fry were drawn at random fromeach <strong>of</strong> the fry hapas and stocked in the1 m 3 and 6 m 3 hapas, respectively, to makea stocking density <strong>of</strong> 50 and 10 fry m -3 ,respectively. Fish were fed to satiation atthree-day intervals.Fish in the hapas were sampled 2 weeksafter stocking and then monthly. Uponcollection <strong>of</strong> the sample, fry were countedand weighed in bulk to estimate growthrate. Mean weight in the two treatments181614121086420WT HIWT LO22-Sep 6-Oct 7-Nov 13-DecFigure 7: Mean weight <strong>of</strong> Clarias gariepinus frystocked at high density (50 fry m -2 ), and lowdensity (10 fry m -2 ) in fine-mesh hapas; verticalbars represent standard error <strong>of</strong> the mean at thegiven date and stocking densitywas assessed to identify a suitable stockingdensity for the practical rearing <strong>of</strong> fry towardsa suitable size and timeframe for tagging.Based on results obtained from this trial, onone hand, a stocking density <strong>of</strong> 50 fry m -2was not suitable for production <strong>of</strong> Clariasgariepinus fry at a suitable size for tagging.A stocking density <strong>of</strong> 10 fish m -2 , on theother hand, resulted in suitable tagging sizefry within a period <strong>of</strong> 6 weeks (Figure 7).CANNIBALISM WITHINFULL-SIB GROUPSA set <strong>of</strong> 4.5 m 3 hapas, 3.0×1.5×1.0 m(length×width×height), was installed in thesame manner as described above to evaluatethe possibility <strong>of</strong> jumpers preying on theirsmaller siblings. Hapas were each stockedwith 25 jumpers (predator group) and 150small fry (prey group). Feeding and otherdaily maintenance treatments were appliedin the same manner as described in the frygrowth experiment except that a total count<strong>of</strong> fry in each hapa was conducted at theend <strong>of</strong> 1 week after stocking. Comparativefry count <strong>of</strong> the two groups was used toexplain the cause <strong>of</strong> fry mortality withinfull-sib groups. No fry loss was observedin the predator group (0%). Comparatively,an average fry loss <strong>of</strong> 47% was observed inthe prey group. This observation suggeststhat cannibalism was the main reason forfry loss in all the families. Natural mortalityboth in the predator group and in the frygrowth trial suggests ruling out this factoras an important cause for mortality in thisstage <strong>of</strong> life.INVESTIGATION OFTAGGING TECHNIQUESAs some families contained larger fry,exploratory tagging <strong>of</strong> large fry wasconducted later in the year on 15 September.Floy tags were used in this trial. Using 420candidates with a mean weight (SE) <strong>of</strong>12.1 g (3.2), survival after tagging was 92%.It appeared from this exploratory trial thatthe size <strong>of</strong> fish is highly important for thesuccess <strong>of</strong> tagging with the critical point

102 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSbeing around 5 g. Fish that were less than5 g did not have a well-developed dorsalmuscle that can hold the tag.Based on this, the fry rearing experimentwas continued for all fish groups to exceedor reach this mean weight. In December2004, fish from the fry rearing experimentaveraged 5.4 g and 13.9 g for the 50 fry m -2and 10 fry m -2 , respectively. Randomsamples from all families in the 50 fish m -2group were allocated to Floy and PIT taggingto evaluate survival after tagging.Different tag types resulted in differentrates <strong>of</strong> tagging success. Survival within 2weeks after tagging was 21% and 84% inthe Floy-tagged and the PIT-tagged groups,respectively. Most <strong>of</strong> the mortality took placewithin 2 days after tagging, suggesting thatFloy tagging may cause more stress onthe tagged fish. Subsequent mortality wasassociated with development <strong>of</strong> ulcers anddiseases. Based on this, it was clear thatPIT tagging was the technique <strong>of</strong> choicefor Clarias gariepinus fingerlings. A secondstage <strong>of</strong> the experiment was conducted toconfirm the hypothesis that difficulties withFloy tagging are due to the body form <strong>of</strong> thefish and the lack <strong>of</strong> a thick dorsal muscle andbody depth that would have facilitated taginsertion on one side and to focus in on themost suitable size <strong>of</strong> fish for PIT tagging.A sample <strong>of</strong> fish from the 10 fish m -2 groupwith an average weight <strong>of</strong> 14.1 g was used forFloy tagging. A total <strong>of</strong> 160 fish were tagged.Mortality subsided 2 days after tagging.Survival, 3 days after tagging, was 75%.For PIT tagging, the two groups <strong>of</strong> fish, 50fish m -2 and 10 fish m -2 , were graded. Some100 individuals with an average weight <strong>of</strong>7.8 g were obtained through grading <strong>of</strong> the50 fish m -2 group while 100 individuals withan average weight <strong>of</strong> 10.3 g were obtainedby grading <strong>of</strong> the 10 fish m -2 group. Survivalafter PIT tagging <strong>of</strong> the two groups was 97%and 94%, respectively. While 5 g appearsto be a reasonable minimum size for PITtagging, it may be safer to grow fry to alarger size than 5 g prior to PIT tagging.COMMUNAL STOCKINGFish were stocked communally in a pondat 4 fish m -2 during the first week <strong>of</strong> March2005. Samples were collected biweekly toevaluate growth and Floy tag retention. Tagretention rate continued to drop graduallyuntil fish reached a mean weight <strong>of</strong> 80 g inmid-May. At that time, tag retention rate was77%. Subsequently, tag retention started todrop much faster. It was, in the PIT-taggedfish, much better. Until mid-May, only 1 fishlost the tag from a total <strong>of</strong> 247 fish. Fishsurvival in September 2005, after a 6-monthgrowth period, was 68% including fish thatlost tags. Mean weight was 234 g. Theremay be a need to use a lower stockingdensity or change the rearing conditions toobtain market-size fish in the experimentalponds.SELECTIONPROGRAM IN 2005The breeding program conducted by theWorldFish Center in Egypt to improvegrowth performance <strong>of</strong> Clarias gariepinus isthe first in the world. Preparations for thereproduction season started in the summer<strong>of</strong> 2005. All four stocks were separated inponds by sex and fed with 32% proteindiet. Females were regularly sampled andchecked for readiness to spawn. When readyto spawn, males and females were pairedin hapas that were installed in a 4,000 m 2earthen pond. Very limited spawningsuccess was achieved where only 9 spawnswere obtained from a total <strong>of</strong> 150 pairs. Itwas then decided to move the fry productionphase into covered concrete tanks wherethe set <strong>of</strong> hapas may be protected fromthe unstable weather conditions and morecontrol can be practised on the fluctuatingwater temperature. Further, intraperitonealinjection <strong>of</strong> Ovaprim, 0.5 mg/kg <strong>of</strong> femaleweight, was used. The results were veryencouraging where 32 pairs that wereinjected produced 25 spawns, <strong>of</strong> which21 produced fry. CFPE injections werealso attempted and produced comparableresults. The spawning activity continuedthrough most <strong>of</strong> September to produce atotal <strong>of</strong> 82 full-sib and half-sib groups. Thesewere the progenies <strong>of</strong> 52 sires and 82 dams.

GENETIC IMPROVEMENT OF CLARIAS GARIEPINUS AT THE WORLDFISH CENTER, ABBASSA, EGYPT 103Fish numbers per family were standardizedto 50 per family and stocked in 4.5 m 3 hapasinstalled in an earthen pond. The remainingfish from each family were kept in a separatehapa as a backup. Because production<strong>of</strong> families was accomplished much laterin the season than in the 2004 spawningseason, the fish did not reach tagging sizein 2005 because <strong>of</strong> the lower temperatureafter spawning and the start <strong>of</strong> winter duringwhich time fish exhibited minimal increase inweight as revealed by periodic sampling.In February 2006, a parasitic infestation,Ichthyophthirius multifilis, was successfullytreated but left only a total <strong>of</strong> 1,075survivors. Tagging was conducted in Mayand fish were communally evaluated. Of theanimals stocked, 73% were recovered withtags. Mortality during communal evaluationwas 15%. Tag loss among the survivors was14%. Data were collected on sex, individualbody weight, standard length, head length,head width, head depth, body width andcaudal width (Table 3). It was important atthis stage to evaluate several traits in orderto identify a suitable selection criterion thatbest expresses the genetic components<strong>of</strong> variation in growth. Preliminary results(unpublished) indicated that there wasgenetic variation in body and morphometrictraits.REFERENCESAgnese, J.F. and G.G. Teugels. 2001. Geneticevidence for monophyly <strong>of</strong> the genusHeterobranchus and paraphyly <strong>of</strong> the genusClarias (Siluriformes, Clariidae). Copeia 2001:548-552.Table 3: Basic statistics for body traits in AfricancatfishStandard Coefficient <strong>of</strong>Traits Mean deviation variation (%)Harvest weight 676.54 189.87 28.1Standard length 468.35 41.25 10.3Head length 106.19 11.09 10.4Head width 69.99 7.42 11.0Head depth 39.85 4.23 10.9Body width 55.13 6.83 12.4Caudal width 38.49 4.64 12.2Bongers, A.B.J., D. Ngueriga, E.H. Eding andC.J.J. Richter. 1995. Androgenesis in the Africancatfi sh, Clarias gariepinus. Aquat. Living Resour.8: 329-332.Islam, M.N., M.S. Islam and M.S. Alam. 2007.Genetic structure <strong>of</strong> the different populations<strong>of</strong> walking catfish (Clarias batrachus L.) inBangladesh. Biochem. Genet. 45: 647-662.Legendre, M., G.G. Teugels, C. Cauty and B.Jalabert. 1992. A comparative study onmorphology, growth rate and reproduction <strong>of</strong>Clarias gariepinus (Burchell, 1822),Heterobranchus longifi lis Valenciennes, 1840,and their reciprocal hybrids (Pisces, Clariidae).J. Fish Biol. 40: 59-79.Nagpure, N.S., B. Kushwaha, S.K. Srivastava andA.G. Ponniah. 2000a. Comparativekaryomorphology <strong>of</strong> African catfish Clariasgariepinus (Burchell) and Asian catfi sh Clariasbatrachus (Linn.). Chromosome Sci. 4: 57-59.Nagpure, N.S., B. Kushwaha, S.K. Srivastava andA.G. Ponniah. 2000b. Karyomorphology <strong>of</strong>African catfi sh Clarias gariepinus (Clariidae).Chromosome Sci. 4: 43-44.na-Nakorn, U., P. Sidthikraiwong, W. Tarnchalanukitand T.R. Roberts. 1993. Chromosome study<strong>of</strong> hybrid and gynogenetic <strong>of</strong>fspring <strong>of</strong> artifi cialcrosses between members <strong>of</strong> the catfi sh familiesClariidae and Pangasiidae. Environ. Biol. Fish.37: 317-322.Nwadukwe, F.O. 1995. Analysis <strong>of</strong> production,early growth and survival <strong>of</strong> Clarias gariepinus(Burchell), Heterobranchus longifilis (Val.)(Pisces: Clariidae) and their F1 hybrids in ponds.Aquat. Ecol. 29: 177-182.Poompuang, S. and U. na-Nakorn. 2004. Apreliminary genetic map <strong>of</strong> walking catfish(Clarias macrocephalus). Aquaculture 232:195-203.Senanan W., A.R. Kapuscinski, U. na-Nakorn andL.M. Miller. 2004. Genetic impacts <strong>of</strong> hybridcatfi sh farming (Clarias macrocephalus x C.gariepinus) on native catfi sh populations incentral Thailand. Aquaculture 235: 167-184.Sukmanomon, S., S. Poompuang and M. Nakajima.2003. Isolation and characterization <strong>of</strong>microsatellites in the Asian walking catfishClarias macrocephalus. Mol. Ecol. Notes3:350-351.Teugels, G.G., C. Ozouf-costz, M. Legendre andM. Parrent. 1992. A karyological analysis <strong>of</strong> theartifi cial hybridization between Clarias gariepinus(Burchell, 1822) and Heterobranchus longifi lisValenciennes, 1840 (Pisces; Clariidae). J. FishBiol. 40: 81-86.

104 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSPROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENTPROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS)Nguyen Hong NguyenScientist, Aquaculture and Genetic Improvement andRaul W. PonzoniPrincipal Scientist, Aquaculture and Genetic ImprovementThe WorldFish Center, PO Box 500 GPO, 10670 PenangMALAYSIAINTRODUCTIONIn this paper we discuss the prospects forthe development <strong>of</strong> a genetic improvementprogram for African catfish (Clariasgariepinus). We do not aim to makean exhaustive review <strong>of</strong> the literature.Based on available knowledge and somepreliminary research results obtained byWorldFish, pre-requisites for the initiation<strong>of</strong> genetic improvement in this speciescan be satisfactorily met, althoughcontrol <strong>of</strong> reproduction in males mayrequire further refinements. We modeledalternative breeding schemes, with anemphasis on development <strong>of</strong> breedingobjectives, selection strategies, and choice<strong>of</strong> testing environments. In parallel withthe development <strong>of</strong> improved pure strains<strong>of</strong> African catfish, we also consideredpossibilities to exploit heterosis andcomplementary effects in this species. Wealso present some thoughts on technicalissues <strong>of</strong> other genetic techniques such assex reversal and chromosome manipulation.Given the advent <strong>of</strong> molecular geneticsand reproductive technologies, we outlinepotential applications <strong>of</strong> marker assistedselection, and in-vitro fertilization usingfresh or frozen sperm in practical selectivebreeding programs. Finally, strategies foreffective dissemination <strong>of</strong> improved fish t<strong>of</strong>armers are also discussed.CHOICE OF THE SPECIESClarias gariepinus is one <strong>of</strong> the Africanspecies <strong>of</strong> choice for future geneticimprovement. It is widely distributed andcultured in many African countries, especiallyin Nigeria where it is the most importantspecies, and in Cameroon, Ghana, andSouth Africa where it ranks high among thecultured species. Although <strong>of</strong>ficial statisticalfigures about total culture area and yieldare not always available, production <strong>of</strong> C.gariepinus has been recognized as a growingone, positively contributing to the social andeconomic development <strong>of</strong> many countriesin the region. Relative to other Africancatfish or species, C. gariepinus showsseveral advantages under a wide range <strong>of</strong>culture conditions, including fast growth onan omnivorous diet and resistance to lowdissolved oxygen and stress. Its biologyand ecology are detailed by Brummett inthis volume.In spite <strong>of</strong> its high production potential,scientific knowledge in the area <strong>of</strong> geneticsfor this species is still very limited, and thereis a paucity <strong>of</strong> information about discretepopulations <strong>of</strong> C. gariepinus within eachcountry or in Africa as a whole. Someearlier studies indicate differences in levels<strong>of</strong> heterozygosity between the wild anddomesticated farm fish (Teugels et al. 1992;Grobler et al. 1994; Van der Bank 1998).Growth <strong>of</strong> farmed fish has declined due topoor management practices <strong>of</strong> hatcherieswhich have not been based on sound geneticnorms for brood stock maintenance andreplacement, and for progeny production.As a first step in the proposed geneticimprovement program, a founder populationbased on the best stocks from differentgeographical areas within sub-regions<strong>of</strong> Africa should be established. Priority

PROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS) 105should be assigned to genetically distinctpopulations, which may be identified bycharacterization at the molecular levelprior to sampling if resources permit. Notethat there is a weak correlation betweenmolecular information and phenotypicperformance in many species (see reviewby Reed and Frankham 2001). The level <strong>of</strong>heterozygosity derived from marker analysisdoes not ascertain genetic potential <strong>of</strong>the population for performance. Beforeassembling the foundation populations, awell designed experiment should be carriedout to evaluate performance <strong>of</strong> locally(regionally) available stocks. Identification<strong>of</strong> superior stocks to be included in thebreeding programs can result in gainsequivalent to a few generations <strong>of</strong> selection,thus saving time and resources. Dependingon availability <strong>of</strong> experimental facilities andresources, four or five stocks included in acomplete diallel cross can be sufficient tocapture abundant genetic variation in thesynthetic population for future selection(Holtsmark et al. 2006). The strategy hasproved successful in farmed aquaculturespecies such as Atlantic salmon (Gjedrem etal. 1991), Nile tilapia (Eknath et al. 2007) andIndian rohu carp (Mahapatra et al. 2006).PRE-REQUISITES TO STARTBREEDING PROGRAMSFOR A NEW SPECIESA formal breeding program in any speciesrequires i) individual tagging, and ii) control<strong>of</strong> reproduction. Exploratory experimentscarried out at the WorldFish Center inAbbassa, Egypt (Rezk 2008 in this volume)indicate a high success rate with individualidentification in African catfish using PIT tags(passive integrated transponder). A suitablesize to be physically tagged is around 5 gor above. Mortality after tagging is low (lessthan 5%). Throughout the rearing period<strong>of</strong> one month in hapas, the retention rateis approximately 96%. In practice, furtherimprovement in survival and tag retentionmay be achieved in a number <strong>of</strong> ways. Acommon practice is that fingerlings shouldbe collected from nursery ponds one daybefore tagging. They should be kept in tankswithout any feed overnight so that morespace will be available in the abdominalcavity for accommodating the PIT tags (thisdoes not apply to cases in which the tagsare injected into the dorsal muscle). One ortwo days after tagging, all the fingerlingsshould be pooled in conditioning tankswithout feed before releasing them tocommunal grow-out in test environments.Tagging <strong>of</strong> additional fish should be doneto replace dead fish from each family. Thesuccess <strong>of</strong> early tagging in African catfish isimportant because it can shorten the period<strong>of</strong> separate family rearing in tanks or hapas.In aquaculture species larvae and fry are toosmall to be physically tagged immediatelyafter birth. Individual families are thus keptin separate hapas which induce an effectcommon to full-sibs sharing the sameenvironment (c 2 ). In freshwater fish species(e.g. tilapia), the c 2 estimated ranges from10 to 30% (Ponzoni et al. 2005; Nguyen etal. 2007).Further, a fully pedigreed breeding programrequires pair matings to enable unequivocalidentification <strong>of</strong> parentage (not massspawning). A mating ratio <strong>of</strong> one male to oneor two females is <strong>of</strong>ten applied, dependingon family structure and experimental design.Induced breeding using human chorionicgonadotropin (HCG) or catfish pituitariesis not a problem in females, but strippingsperm from males still remains impossibledue to the physiology <strong>of</strong> the testis. This maymake the implementation <strong>of</strong> more elaboratemating schemes difficult or impossible(e.g., incomplete factorial design or factorialmating by set). An experiment at Abbassawas conducted to examine alternativereproduction systems for this species (Rezk,2008 in this volume). By lowering the waterlevel in the pond in order to increase watertemperature (optimum around 25ºC), naturalspawning <strong>of</strong> parental pairs was achievedin hapas. The success rate <strong>of</strong> mating wasgreater than 80%, although mating <strong>of</strong> maleswith a second female sometimes requiredthe injection <strong>of</strong> a low dose <strong>of</strong> hormonefor males. In this scheme, identification <strong>of</strong>‘ready to spawn’ (or ripe) females to pairwith males is critical. Ideally, females shouldbe greater than 1.5 years <strong>of</strong> age; however,this would prolong the production cycleand increase the generation interval. Undera well controlled environment, females

106 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUScan reproduce effectively at 1 year <strong>of</strong> agewhich can shorten the generation intervalin this species. Also note that the eggsize increases with age <strong>of</strong> females. Thereare thus possibilities <strong>of</strong> maternal geneticeffects on traits during early stages <strong>of</strong>growth. Genetic evaluation systems shouldinclude the maternal genetic effects if theyare tested to be significant. In summary,natural spawning <strong>of</strong> African catfish in hapasis feasible, although there is still room forfurther improvement to ensure that thebenefits from mating parents <strong>of</strong> high geneticvalue are fully realized.POSSIBLE BREEDINGSCHEMESDue to the important role <strong>of</strong> Clariasgariepinus for aquaculture in Africa, severalcountries on this continent have shown greatinterest in developing genetic improvementprograms for this species. It is, however,impossible to run individual programsin each country. Genetic improvementprograms require an initial investment aswell as funding for recurrent annual runningcosts, and a physical infrastructure andskilled human resources. A proposedstrategy is to establish sub-regionalbreeding programs in West-Central, Eastand southern Africa linked to a research andtraining facility at Abbassa, Egypt in NorthAfrica. The programs can develop one ormore improved lines <strong>of</strong> C. gariepinus for usewithin each sub-region.Regardless <strong>of</strong> locations or regions, thegenetic improvement program for Africancatfish should start with selection for bodyweight at harvest. Food security is still anissue in African countries, and the fish arepriced based on live weight (or size) atlocal markets. So far, information aboutthe level <strong>of</strong> genetic variation in body traitsis not available for African catfish, althoughphenotypic difference in growth amongjuvenile individuals was observed by Martinet al. (2005). Assuming that the heritabilityfor market weight in African catfish is0.30, and the maternal and commonenvironmental effect is 0.15, the genetic gainmay be predicted to be in the order <strong>of</strong> 10%per generation (one year), as reported forother species (e.g. Ponzoni et al. 2005). Theaccumulated genetic gain <strong>of</strong> the programafter 3 or 5 years would be 30 and 50%,respectively.Once the improvement <strong>of</strong> body weightis satisfied and as the program unfolds,the breeding objectives for African catfishcould be expanded to include other traits<strong>of</strong> economic importance (survival and feedintake). Survival is one <strong>of</strong> the major technicalconstraints in hatcheries and grow-outsystems for catfish. Survival rate affects thenumber <strong>of</strong> fish harvested and marketed.Maximizing viability <strong>of</strong> the fish is the ultimatetarget <strong>of</strong> any production system.Feed is a major production cost, accountingfor 60-70% <strong>of</strong> the total. Genetic improvementin growth is undesirably associated withincreased feed intake. The bigger fish willeat more and thus add costs to productionsystems. Therefore, inclusion <strong>of</strong> the threetraits (harvest weight, survival and feedintake) in the breeding objectives for C.gariepinus is perceived to be sufficient forthe medium term future. Other importanttraits such as fillet yield, flesh qualityand disease resistance may emerge ascandidates at a later stage. We used aneconomic model based on a standard pr<strong>of</strong>itequation defined as the difference betweencosts and returns to derive economic valuesfor the traits in the breeding objective.Details <strong>of</strong> the approach are given in Ponzoniet al. (2007). Unfortunately, parameters forproduction traits in African catfish were notfound in the formal literature. We made anumber <strong>of</strong> assumptions regarding growthdata and parameter estimates as shown inTable 1.Means and standard deviations for bodyweight are adapted from Volckaert andHellemans (1999) and were used to developlikely heritability values. Parameters forsurvival rate and the genetic correlationbetween body weight and survival are takenfrom the means <strong>of</strong> 14 studies reviewed inthe literature. Feed intake was calculatedassuming a feed conversion ratio <strong>of</strong> twoduring the grow-out period. A coefficient <strong>of</strong>variation (30%) was assumed to calculate

PROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS) 107the phenotypic standard deviation for feedintake. Heritability for feed intake and itscorrelations with body weight and survivalare not available for any aquaculturespecies, and hence they were adapted fromthe literature review <strong>of</strong> several studies inanimals. In terms <strong>of</strong> population structure,the following assumptions were made:i) the pedigree consisted <strong>of</strong> 100 families(50 sires and 100 dams),ii) there were 20 female and 20 maleprogeny tested per family, that werepotential selection candidates,iii) the proportions <strong>of</strong> selected animalswere 15% in females and 7.5% in males(three times greater than the actualneed in both sexes), andiv) selection was based on BLUP using fullpedigree information.Note that feed intake was included inthe breeding objectives, but it was notconsidered as a selection criterion due to alack <strong>of</strong> practical methods <strong>of</strong> measurement.The genetic change per year for individualtraits in the breeding objective, standardTable 1: Phenotypic and genetic parameters forharvest weight (BW), survival rate (SR) and feedintake (FI) in African catfishBW (g) SR (%) FI (g)Mean 1000 85 2000h 2 0.30 0.10 0.25σ P161 35.7 400Phenotypic (above) and genetic (below) correlationsBW 0.20 0.70SR 0.20 0.3FI 0.70 0.30Common environmental effects and correlationsc 2 0.15 0.08 0.15BWSR 0.20FI 0.70 0.20Table 2: Genetic gain per year (∆ G) for each trait,standard deviation <strong>of</strong> (σ I) the index and <strong>of</strong> thebreeding goal, accuracy <strong>of</strong> selection (r IH= σ I/σ H)and overall gain in economic units; all figures indollars ($) refer to US dollarsGenetic gain and Index property Actual unitHarvest weight (g) 63.5Survival (%) 5.2Feed intake (g) 111.4σ H($) 184.4σ I($) 59.9Accuracy <strong>of</strong> selection 0.33∆ Gin economic units ($) 102.6deviations <strong>of</strong> the index and <strong>of</strong> the breedinggoal, accuracy <strong>of</strong> selection, and overall gainin economic units are presented in Table 2.The selection environment <strong>of</strong> our choice isin earthen pond with standard commercialfeed and management practices. Pondculture is the prevailing environment(>90%) in a majority <strong>of</strong> African countries,especially in Nigeria, Ghana, Kenya andMalawi, which are likely to become keyplayers in the development <strong>of</strong> breedingprograms for African catfish. There are alsoother production systems such as smallscalefarms (SC) utilizing agricultural byproductsmixed with complete feed, semiextensivescale (SE) using flow-through(pond combined with concrete tanks) withgood quality feed, or intensive scale (IS)using recirculation systems. It is possiblein principle that the genetic gains achievedin the selection environment will not befully realized in these diverse productionsystems. In other words, there is a possibility<strong>of</strong> a genotype by environment interaction(G×E) on performance <strong>of</strong> African catfish.We considered three main farming systems:small scale (SC), semi-extensive (SE) andintensive scale (IS). Since the SC systemis close to the pond environment, the G×Eeffect is likely insignificant. In this case,we assumed that the genetic correlationbetween trait expressions between the twoenvironments was 0.9. On the other hand,there is likely moderate G×E effect betweenpond and semi-extensive system, andsignificant G×E effect between pond andintensive scale. The genetic correlations <strong>of</strong>the same traits between these pair-wiseenvironments assumed were 0.7 and 0.5,respectively. Selection index theory using theparameter values and pedigree informationas described above was used in all simulationstudies. The effects <strong>of</strong> G×E interaction onthe underlying components <strong>of</strong> genetic gainare given in Table 3. The magnitude <strong>of</strong> G×Ehad strong effect on accuracy <strong>of</strong> selection(r IH) and standard deviations <strong>of</strong> the index(σ I). Changes in the genetic gain for all traitswere proportional to the decrease in themagnitude <strong>of</strong> the genetic correlation from1.0 to 0.5. Decrease in accuracy <strong>of</strong> selectionand in standard deviation <strong>of</strong> indices was themain source <strong>of</strong> loss in genetic gain.

108 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSDespite the loss <strong>of</strong> genetic gain shown inTable 3, a single breeding program understandard pond environment is recommendedfor African catfish. A separate program foreach environment is entirely infeasible indeveloping countries where resources andexperience are limited. We made a veryconservative assumption that there werelarge effects <strong>of</strong> G×E interaction. However,results from the literature across severalaquaculture species indicate that G×Einteraction is not <strong>of</strong> biological importancefor body performance, with the geneticcorrelation estimates for the same traitsunder a range <strong>of</strong> environments studied allclose to unity (Ponzoni et al. 2005; Fishbacket al. 2002; Kause et al. 2003; Gitterle et al.2005; Swan et al. 2007). In practical breedingschemes, a number <strong>of</strong> strategies can beapplied in order to minimize G×E effects. Forinstance, recording performance <strong>of</strong> relatives<strong>of</strong> selection candidates in productionenvironment to be jointly analyzed with thenucleus data may assist in the management<strong>of</strong> G×E effects.CROSSBREEDINGCrossbreeding and hybridization are appliedto utilize heterosis or complementary effect.Heterosis is the superiority in performance<strong>of</strong> <strong>of</strong>fspring over the average for theirparents. It is shown mainly in lowly heritabletraits (e.g. survival rate, reproductive traits).Complementarity is the combination <strong>of</strong>favorable characteristics from parentallines involved in crossings. For Africancatfish, a typical example is the interspecifichybridization between Clarias gariepinusmale and Clarias macrocephallus female.The hybrid shows better flesh quality anddisease resistance than their parents, andmakes up approximately 90% <strong>of</strong> catfishproduction in Thailand. Thai farmers favorculturing the hybrid due to their highermarket price and higher efficiency <strong>of</strong>production. In Bangladesh, the Clariasgariepinus × Clarias batrachus hybrid alsogives better hatching rate and survival thanthe pure parents, although the reciprocalcross is sterile or has a high mortality duringnursing (Khan et al. 2002).In addition, intergeneric hybridizationbetween Clarias gariepinus andHeterobranchus longifilis has been used toimprove growth performance and carcassyield (Hecht and Lublinkh<strong>of</strong> 1985; Legendreet al. 1992; Teugels et al. 1992; Nwadukwe1995). The hybrid was thought to be sterile,although it has been recently shown to havethe capacity to interbreed with wild Clariasgariepinus (see Brummett, in this volume).Further, the fish exhibit aggressive behaviorand large variation in body weight (Fleuren,in this volume), and reduced immunityleading to high susceptibility to Henneguyainfections relative to pure parents (Euzet andPariselle, 1996).Neither interspecific nor intergenerichybridization appear to have beensystematically studied in African catfish.For instance, the level <strong>of</strong> heterosis foreconomically important traits is still notknown with certainty. If the heterosisadvantages were small or negligible in thisspecies, it would not be necessary to wastetime in developing crossing systems. Thisis because culture <strong>of</strong> hybrids has raisedconcerns regarding the introgression <strong>of</strong>Clarias gariepinus genes into local or wild fishwhich may have effects on genetic integrity<strong>of</strong> native species. On the other hand, if thelevel <strong>of</strong> heterosis were significant, differentbreeding objectives could be defined todevelop specialized lines for alternativecrossbreeding systems. One example wouldbe to develop a fast growth and high survivalTable 3: Genetic gain per year (∆ G) for each trait, standard deviation <strong>of</strong> the index (σI), accuracy <strong>of</strong>selection (r IH) and overall gain in economic unitsGenotype by Direct responses Correlated responses σ IAccuracy ∆ Ginenvironment ($) <strong>of</strong> economicinteraction BW (g) SR (%) FI (g) BW (g) SR (%) FI (g) selection units ($)R g= 0.9 63.5 5.2 111.4 57.2 4.9 100.2 55.0 0.30 94.7R g= 0.7 63.5 5.2 111.4 44.5 3.6 77.9 41.6 0.23 71.6R g= 0.5 63.5 5.2 111.4 31.8 2.6 55.7 29.9 0.16 51.4

PROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS) 109line, and a separate line selected to reducecompetition effect or aggressiveness inClarias gariepinus. The resultant crossbreds<strong>of</strong> the two lines combining advantageouscharacteristics <strong>of</strong> their parents would beused in commercial production. This overallapproach has worked well with several animalspecies, but has been completely neglectedin fish. Note, however, that running multiplebreeding programs to develop specializedstrains requires a high level <strong>of</strong> investmentand management. In summary, the area <strong>of</strong>crossbreeding and hybridization in Africancatfish deserves further study to enable thedesign <strong>of</strong> proper breeding strategies for thisspecies under the practical conditions <strong>of</strong>African countries.SEX REVERSAL ANDCHROMOSOMEMANIPULATIONIn African catfish, sex reversal to producemonosex male population by using thehormone (17 α-méthyltestoterone) is noteffective (Pongthana 2001). Chromosomeresearch in this species includedmeiogynogenesis (Volckaert et al. 1994)or mitogynogenesis (Varadi et al. 1999).By applying physical shocks (either coldor heat) to produce diploids, the successrate is relatively high regarding survivaland hatchability (up to 81%, Varadi et al.1999). However, a considerable amount <strong>of</strong>residual heterozygosity is still found, that is,the gynogenes are not fully homozygous(Galbusera et al. 2000). In these studies,the survival rate and the growth rate werealways lower for the gynogenetic individualsthan for their parents.Gynogenesis is also applied to produce sterilepolyploids with higher growth performanceor higher fillet proportion. Different forms <strong>of</strong>polyploidy such as triploids (Henken et al.1987), tetraploids (Varadi et al. 1999) andtriploid hybrids (Na-Nakorn et al. 2004)can be successfully produced. However,there are no advantages in performance<strong>of</strong> triploids over diploids in African catfish(Henken et al. 1987; Na-Nakorn et al. 2004).In other fish species, growth <strong>of</strong> the triploidsis variable, even lower than the diploids(reviewed by Dunham 2004, and Rasmussenand Morrissey 2007).Until now, chromosome manipulation hasbeen found to serve mainly for researchpurposes, namely generating inbred linesfor genomic studies (linkage mapping,study <strong>of</strong> gene expression) (reviewedby Komen and Thorgaard 2007) or forapplications in genetic conservation andprotection <strong>of</strong> genetic diversity <strong>of</strong> nativepopulations (Dunham 2004; Rasmussenand Morrissey 2007). So far, there havenot been any types <strong>of</strong> polyploids <strong>of</strong> Africancatfish cultured under either small or largescale in any country, even with popular foodspecies such as tilapia or salmon. The mostwidely used application <strong>of</strong> chromosomemanipulation has been in bivalve shellfish, inparticular triploid oysters. It is obvious thatinvestment in research and development <strong>of</strong>gynogenesis techniques for African catfishneeds justification from an economicviewpoint. In addition, there are still technicalconstraints associated with the techniquesand their ease <strong>of</strong> application. However, theymay be useful in the multiplication phaseif production systems show biologicaland economic benefits from the culture <strong>of</strong>single sex or sterile populations, but therehas been a lack <strong>of</strong> commercial protocolsfor practical production. The techniquedepends greatly on laboratory work, whichmay not be perceived as a readily availableservice providing a potential solution in thecontext <strong>of</strong> African countries. If resourcesand funding were available, such researchcould be encouraged to be carried outin universities or research institutions t<strong>of</strong>urther refine the techniques. Given thatfunding is <strong>of</strong>ten limiting, it would seem wiseto invest in activities that can result in rapidand sustainable improvement in quality andperformance <strong>of</strong> the fish in order to meetbasic protein demand <strong>of</strong> poor people (e.g.,selective breeding). The economic benefitfrom the genetic improvement programsin aquaculture species is substantial. Theycould make a significant contribution to thenational economy and to food security indeveloping countries.

110 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSPOTENTIAL APPLICATIONOF MOLECULARINFORMATION ANDREPRODUCTIONTECHNOLOGIESMOLECULAR GENETICS ANDMARKER ASSISTED SELECTIONMolecular research in African catfish has s<strong>of</strong>ar focused on genetic characterization, byusing different markers (mainly allozymesand recently microsatellites) to estimatefrequency <strong>of</strong> alternative alleles, level <strong>of</strong>heterozygosity and to measure geneticdistance between domesticated and wildpopulations (Van der Bank et al. 1992),between genera Clarias gariepinus vs.Heterobranchus longifilis (Teugels et al. 1992)or between species Clarias gariepinus vs. C.anguilaris, C. batrachus or C. macrocephalus(Agnese et al. 1997; Na-Nakorn et al. 2002;Mohindra et al. 2007). In 2002, Kovasc andcoauthors reported two sex-linked loci inmales <strong>of</strong> African catfish which can be usefulfor early sexing <strong>of</strong> the fish. Sennan et al.(2004) also investigated potential impacts <strong>of</strong>introgressive hybridization <strong>of</strong> African catfishon their local Asian walking catfish Clariasmacrocephalus.We conducted a thorough literature searchthrough different databases, but could notfind any genetic linkage or physical mapsin African catfish. There have not beenany quantitative trait loci (QTLs) or geneswith major effects detected in this species.At the present time, molecular geneticsresearch in African catfish is still very limited,and far behind other aquatic species orfarm animals. However, available markershave two possible applications: usinggenetic markers for population analysis,and using DNA fingerprinting for genetictagging. Firstly, genetic characterization <strong>of</strong>strains could be useful to identify potentialcandidate populations before establishing abase population for the later conduct <strong>of</strong> agenetic improvement program. Due to theusual constraints with physical facilities,not all available strains or populations canbe accommodated in breeding programs.Marker analysis can help to identifygenetically distinct populations. The secondpossibility is the application <strong>of</strong> DNA tagging.Parentage testing and pedigree verificationhas four main advantages: increasing thenumber <strong>of</strong> families tested without the needfor increasing tanks and ponds, reducingeffects common to full-sibs, shorteninggeneration interval, and consequentlyincreasing genetic gain. Both experimentaland theoretical results show that with theavailability <strong>of</strong> microsatellite markers, pedigreeanalysis can give very high degree <strong>of</strong>accuracy across aquatic species. However,the technology is still very expensive,the cost <strong>of</strong> genotyping from $10-20 1 persample ($2-3 per microsatellite). Therefore,we need to carry out cost-benefit analysisbefore including the technology in geneticimprovement programs. Also note thatgenetic tagging cannot completely replacephysical tags because the animals still needto be physically tagged for identification,genetic evaluation and selection.We may assume that in the near future therewill be: 1) a fully pedigreed breeding programfirmly established in Clarias gariepinus, and2) molecular information such as linkagemappings, QTLs or genes <strong>of</strong> known effectin important traits in this species. Thereare two main types <strong>of</strong> markers: direct andlinked markers. Corresponding to eachtype <strong>of</strong> marker, there are different methods<strong>of</strong> selection. To the best <strong>of</strong> our knowledge,we have not found reports on any functionalmutations or candidate genes controllingeconomically important traits in aquaticspecies. Therefore, at this stage, there isno opportunity for direct gene assistedselection or introgression assisted selection.With linked markers, there are two possiblemethods <strong>of</strong> selection: marker-assistedselection in crossed populations betweeninbred lines, and marker-assisted selectionwithin strains (Dekkers 2004). For eachmethod, three strategies can be applied,namely: 1) selection based on molecularscore alone, 2) tandem selection: selectionon molecular markers and then selectionon estimated breeding values (EBV), and 3)index selection combining the two methods.In a simulation study, Zhang and Smith(1992) compared three different selectionstrategies and found that genetic gain is1 All fi gures given in $ refer to US dollars.

PROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS) 111highest for index selection combining bothpolygenic EBV and quantitative trait lociEBV. It is followed by best linear unbiasedprediction (BLUP) selection and it is lowestfor selection based on markers alone. Formarker-assisted selection within strains, itsefficiency depends on four parameters: type<strong>of</strong> trait measurements, level <strong>of</strong> heritability,size <strong>of</strong> QTL effects, and recombination rate(Meuwissen and Goddard 1996). In short,marker assisted selection (MAS) is beneficialfor traits which are difficult to measure (e.g.flesh quality) and for traits with low heritability(disease resistance). In summary, with thecurrent stage <strong>of</strong> development there are bothtechnical and economic limitations in orderto apply effectively MAS in practical breedingprograms. There is a general consensusthat investments in molecular research havebeen large, but that by contrast benefitshave been generally small.Recently, there have been two keydevelopments. The sequencing <strong>of</strong> livestockgenome leads to the discovery <strong>of</strong> thousands<strong>of</strong> single nucleotide polymorphism (SNP), andthe cost <strong>of</strong> genotyping per SNP is thereforesignificantly reduced, only 1-10 centscompared with 2-3 dollars per microsatellitemarker. This is opening possibilities forgenomic selection. Meuwissen et al. (2001)were the first to propose genomic selection(GS). In principle, genomic selectionpredicts breeding values for a large number<strong>of</strong> haplotypes across the entire genome.It is equivalent to the BLUP method, butwith the relationship matrix estimated frommarkers. Simulation studies showed thatGS can increase response two-fold andreduce the cost <strong>of</strong> breeding programs,especially in dairy cattle where progenytesting is long and expensive (Schaeffer2006). The efficiency <strong>of</strong> genomic selectionis high. The correlation between genomicEBV and pedigree EBV ranges from 0.64to 0.94, depending on the characteristics<strong>of</strong> the traits in question. It also depends onthe number <strong>of</strong> SNP, linkage disequilibriumbetween QTL and markers, marker allelefrequencies. One question is: how manySNP are needed to apply GS? Studiesshow that approximately 30,000 SNP arerequired for GS within strain or populationand 50,000 SNP for GS across populations(e.g. Hayes et al. 2006). In a recent review,Kadarmidden and Reverter (2007) mentionthat genetic evaluation <strong>of</strong> about 100,000SNPs is approximately equivalent to onebased on infinitesimal gene model theory.The application <strong>of</strong> GS in practical breedingprograms has started for dairy cattle inAustralia, with 15,000 SNP (Tier et al. 2007).In New Zealand and the Netherlands, GShas also been initiated in dairy cattle andbroilers. The potential value <strong>of</strong> GS in fish isstill to be ascertained.REPRODUCTIVE TECHNOLOGIESWe consider two possible reproductivetechnologies: in-vitro fertilization andcryopreservation. In-vitro fertilization (IVF)has two main advantages, although strippingsperm in males <strong>of</strong> African catfish is stillimpossible. IVF allows the design <strong>of</strong> differentmating schemes, and the management <strong>of</strong>inbreeding accumulation. One example isfactorial mating which mainly consists <strong>of</strong>four designs: complete, incomplete, factorialby set and rectangular mating. Benefits<strong>of</strong> factorial mating include: 1) increasedaccuracy <strong>of</strong> parameter estimation andthus accuracy <strong>of</strong> selection and, 2) reducedinbreeding. This may have been becausefactorial matings, when compared withthe nested design, increase the number <strong>of</strong>half-sib families and decrease number <strong>of</strong>full-sib families, thus reducing the risk <strong>of</strong>selecting many individuals from the sameparents (Sørensen et al. 2005). A number<strong>of</strong> theoretical studies (e.g. Dupont-Nivet etal. 2006) show that given the same effectivepopulation size (Ne), factorial matings canresult in greater genetic gain and lowerinbreeding than hierarchical nested andsingle pair matings.Since the 1980s cryopreservation <strong>of</strong> milt hasbeen successful in African catfish. Cryopreservation<strong>of</strong> milt can play an importantrole in a pyramid breeding structure. Inselection programs at the nucleus level,cryopreserved milt may be used as a controlto measure genetic gain with minimum bias.This is mainly because the frozen spermcan present a wider genetic base than arandom unselected control <strong>of</strong> limited sizeand there is no accumulative genetic driftover time. Furthermore, cryopreservedmilt can be tactically used between year

112 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSclasses to reduce the risk <strong>of</strong> inbreeding inthe selected population. In the future, oncelarge scale genetic evaluation is underway,cryopreserved sperm can be used tocreate genetic connectedness betweenpopulations. Moreover, the establishment<strong>of</strong> a gene bank <strong>of</strong> cryopreserved milt wouldbe useful for the conservation <strong>of</strong> geneticresources. However, there are also technicaldifficulties with male catfish; the collectionand storage <strong>of</strong> sperm are still difficult. Afew studies using cryopreserved sperm forartificial fertilization also reported malformedlarvae (Horvath and Urbanyi 2000; Miskolcziet al. 2005). Therefore, there is a need torefine the techniques before widespreadapplication.DISSEMINATION OFIMPROVED FISHCurrently, the development <strong>of</strong> catfishproduction in Africa has taken placein the absence <strong>of</strong> any formal breedingstructure. Among nine African countriesthat participated in the workshop on “Thedevelopment <strong>of</strong> a genetic improvementprogram for Clarias gariepinus”, two thirdsdo not have any breeding centers or researchstations where a genetic improvementcould be immediately initiated for thisspecies. In all countries, there are only a fewprivate hatcheries with limited capacity forproducing and supplying adequate quantityand good quality fry to local farmers. Fryand fingerling prices are generally highin many countries (ranging from $0.1–0.2per piece <strong>of</strong> 5-10 g). Most farmers arenot able to afford or are not willing to buydue to concerns over fish quality. A widelyobserved phenomenon is that hatcheriesproduce fry from only a small number <strong>of</strong>brook stock, and the breeders are usuallykept over a very long period (5 to 10 years).Due to poor management and maintenance,the quality <strong>of</strong> brood stock has deteriorated.In addition, generally there are no broodstock replacement schemes in place, andwhen there are, the replacement rate isvery low (mainly from on-farm stock). Thesefactors may be largely responsible for thepoor performance <strong>of</strong> the fish, as observedin several systems <strong>of</strong> catfish farming inAfrican countries. As a consequence<strong>of</strong> the poor management in hatcheries,the accumulation <strong>of</strong> inbreeding (with itsassociated negative effects) is inevitable.Furthermore, sourcing brood stock fromgrow-out ponds rather than from the wild,and the resulting high levels <strong>of</strong> inbreedingaccumulated over time is believed to be one<strong>of</strong> the main reasons for growth decline inthis species (e.g., in Uganda). The commonpractice <strong>of</strong> selecting brood stock based onits readiness to spawn may also lead to aloss <strong>of</strong> performance as the practice exertsan indirect negative effect on weight atharvest. The conclusion from this state <strong>of</strong>events is that there is a clear need, in parallelwith the genetic improvement at the top <strong>of</strong>the pyramid breeding structure, to establisha network <strong>of</strong> public-private hatcheries.The hatcheries should specialize in themultiplication <strong>of</strong> the improved stock understrict technical protocols provided by localgovernments and international agencies (e.g.WorldFish) to ensure that high quality seedstock reaches the farmers and producers intheir respective countries. Ponzoni (2006)and Nguyen and Ponzoni (2006) discussstrategies for effective dissemination <strong>of</strong>improved fish strains.We again stress that genetic improvementis not particularly useful by itself unless theimproved fish are disseminated to farmersand producers. Our earlier study indicatedthat the economic benefit from a geneticimprovement program depends greatlyon the adoption rates <strong>of</strong> improved fish bythe industry and the dissemination rate t<strong>of</strong>armers. Based on the same approach,the economic benefit from the geneticimprovement program in African countries(using Nigeria as an example) would be from$7.6, $23.8 and $48.1 million, correspondingto adoption rates <strong>of</strong> 10, 30 and 60%,respectively (Figure 1). The calculations arebased on the total current production <strong>of</strong>25,000 t in Nigeria in 2006 (Williams et al.in this volume), and a market weight <strong>of</strong> thefish <strong>of</strong> 1 kg, with the average price acrossAfrican countries <strong>of</strong> $3.0 per kilogram <strong>of</strong> livefish. The dissemination <strong>of</strong> improved fish tothe industry is a complex issue requiringtremendous efforts from local governmentsin terms <strong>of</strong> capacity building <strong>of</strong> the extensionnetwork, hands-on training <strong>of</strong> farmers,

PROSPECTS FOR DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM IN AFRICAN CATFISH (CLARIAS GARIEPINUS) 113development <strong>of</strong> credit systems, social andeconomic policies as well as marketingsystems for agricultural products.CONCLUSIONIt is concluded that investment in thegenetic improvement programs for Clariasgariepinus can result in substantialeconomic benefits contributing to thenational economy <strong>of</strong> African countries.The minimum benefit to cost ratio isapproximately 15:1, corresponding to aneconomic benefit <strong>of</strong> at least $7.6 million.The efficiency <strong>of</strong> the breeding programsis also dependent on various biological,economic, environmental and operationalfactors. Technical risks due to deviationsfrom theoretical predictions are low unlessmatters out <strong>of</strong> human control arise duringthe practical implementation <strong>of</strong> the program.However, the success <strong>of</strong> the program wouldrequire concerted efforts from internationalorganizations, local governments and otherrelevant agencies. Capacity building <strong>of</strong>local staff and institutions is another area<strong>of</strong> priority. The establishment <strong>of</strong> stronglinkages among governments and researchinstitutions would facilitate the effectivedissemination <strong>of</strong> improved fish to countriesin the region.Economic benefit ($ million)605040302010015459010 30 60Adoption ratesFigure 1: Economic benefit and benefit to costratio (at top <strong>of</strong> the bar) corresponding to differentadoption rates <strong>of</strong> improved fish by the industryREFERENCESAgnèse, J-F., G.G. Teugels, P. Galbusera, R.Guyomard and F. Volckaert. 1997. Morphometricand genetic characterization <strong>of</strong> sympatricpopulations <strong>of</strong> Clarias gariepinus and C.anguillaris from Senegal. J. Fish Biol. 50:1143–1157.Dunham, R.A. 2004. Aquaculture and fi sheriesbiotechnology: genetic approaches. CABIInternational, Oxfordshire, UK.Dupont-Nivet, M., M. Vandeputte, P. Haffray andB. Chevassus. 2006. Effect <strong>of</strong> different matingdesigns on inbreeding, genetic variance andresponse to selection when applying individualselection in fi sh breeding programs. Aquaculture252: 161–170.Eknath, A.E., H.B. Bentsen, R.W. Ponzoni, M. Rye,N.H. Nguyen, J. Thodesen and B. Gjerde. 2007.Genetic improvement <strong>of</strong> farmed tilapias:composition and genetic parameters <strong>of</strong> asynthetic base population <strong>of</strong> Oreochromisniloticus for selective breeding. Aquaculture273: 1–14.Ergene, S., E. Portakal and A. Karahan. 1999.Karyological analysis and body proportion <strong>of</strong>catfi sh (Clariidae, Clarias lazera, Valenciennes,1840) in the Göksu Delta, Turkey. Trans. J. Zool.23: 423–426.Euzet, L. and A. Pariselle. 1996. Le parasitismedes poisons Siluroidei: un danger pourl’aquaculture? Alternative life history strategies<strong>of</strong> catfi shes. Aquat. Living Resour. 9 (Hors Série):145–151.Fishback, A.G., R.G. Danzmann, T. Sakamoto,M.M. Ferguson and J.P. Gibson. 2002. Estimates<strong>of</strong> genetic parameters and genotype byenvironment interactions for growth traits <strong>of</strong>rainbow trout (Oncorhynchus mykiss) as inferredusing molecular pedigrees. Aquaculture 206:137–150.Galbusera, P., F.A.M. Volckaert and F. Ollevier.2000. Gynogenesis in the African catfi sh Clariasgariepinus (Burchell, 1822). III. Induction <strong>of</strong>endomitosis and the presence <strong>of</strong> residual geneticvariation. Aquaculture 185: 25–42.Gitterle, T., M. Rye, R. Salte, J. Cock, H. Johansen,C. Lozano, J.A. Suárez and B. Gjerde. 2005.Genetic (co)variation in harvest body weightand survival in Penaeus (Litopenaeus) vannameiunder standard commercial conditions.Aquaculture 243: 83–92.Gjedrem, T., H.M. Gjøen and B. Gjerde. 1991.Genetic origin <strong>of</strong> Norwegian farmed Atlanticsalmon. Aquaculture 98: 41–50.Grobler, J.P. and F.H. van Der Bank. 1994. Allozymepolymorphism and phenotypic variation inAfrican catfish (Clarias gariepinus). Comp.Biochem. Physiol. Part B: Biochem. Mol. Biol.107 (1): 111–116.

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116 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSANNEX AWORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENTPROGRAM FOR CATFISH – CLARIAS GARIEPINUSLIST OF PARTICIPANTSCAMEROONDr. Randall E. BrummettThe WorldFish CenterIITA-Humid Forest Ecoregional CenterBP 2008 (Messa), Yaoundé, CameroonTel: +237 22 23 74 34E-mail: r.brummett@cgiar.orgDr. David NguengaSenior Research Officer (Aquaculture)Institute <strong>of</strong> Agricultural Research forDevelopment (IRAD)Foumban Specialized Research StationP.O. Box 255, Foumban, CameroonTel: +237 99 83 52 09; 77 31 10 37Fax: +237 33 48 30 13E-mail: nguengadavid@yahoo.frEGYPTDr. Mahmoud A. RezkThe WorldFish CenterRegional Research Center for Africa andWest AsiaP.O. Box 1261, Maadi, Egypt.Tel: +20 (55) 3404227, 3404228, 3405579Fax: + 20 (55) 3405578E-mail: mrezk@worldfish-eg.orgDr. Gamal Othman El-NaggarThe WorldFish CenterRegional Research Center for Africa andWest AsiaP.O. Box 1261, Maadi, EgyptTel: +20 (55) 3404227, 3404228, 3405579;+20 12 7456866 (M)Fax: +20 (55) 3405578E-mail: gelnaggar@worldfish-eg.orgEng. Mohammed Gouda El SayedHead, Fayoum Fish Farming Association9 Elwwhda Street, Bagous Elfayoum City,EgyptTel: +20 84 6307575, 6300580;+20 106089107(M)Fax: +20 84 6354608, 6830108E-mail: mgouda1956@yahoo.comDr. Ismail A. RadwanEgyptian Aquaculture Center27, Officers’ Housing, Mostafa KamelSidi Gaber, Alexandria, EgyptTel: +20 10 121 2130Fax: +20 47 913 5636E-mail: somaa_97@hotmail.comGHANAMr. Felix AttipoeWater Research InstituteP.O. Box M32Accra, GhanaTel: +233 251 20786 (O)+233 28728 8804 (M); +233 2444 54432 (M)Fax: +233 21 777 170E-mail: fattipoe@hotmail.comMr. Seth Koranteng AgyakwahWater Research InstituteP.O. Box M32Accra, GhanaTel: +233 251 20786 (O); +233 244 610181Fax: +233 21 777 170E-mail: agyaseth@yahoo.comISRAELPr<strong>of</strong>. Dr. Sheenan HarpazHead, Department <strong>of</strong> AquacultureInstitute <strong>of</strong> Animal Science, AgriculturalResearch OrganizationThe Volcani Center, P.O. Box 6Bet Dagan 50250, IsraelTel: +972 50 6220388Fax: +972 39 605667E-mail: harpaz@agri.huji.ac.ilKENYAMs. Nancy K. GitongaFishAfricaP.O. Box 64358 00620Nairobi, KenyaTel: +254 722 967739 (M)Fax: +254 20 513539E-mail: n.gitonga@fishafrica.co.ke

LIST OF PARTICIPANTS 117George Owiti OsureSenior Fisheries OfficerSagana Aquaculture CentreP.O. Box 26 - 10230Sagana, KenyaTel: +254 60 46041, +254 721 971882(M)Fax: +254 60 46041E-mail: gowiti2002@yahoo.comDr. Harrison Charo-KarisaProgram Coordinator AquacultureKenya Marine and Fisheries ResearchInstituteSangoro Aquaculture Research StationP.O. Box 136, Pap-Onditi,KenyaTel: +254 725 555143E-mail: Harrison.Charo@gmail.com; charoh_se@yahoo.comJoram Achuku OyooThe Technical DirectorA.F.W.A.Box 339- Rongo 40404, KenyaTel: +254 733 232699E-mail: afwaq@yahoo.comMALAWIBrino B. ChirwaHead, National Aquaculture CenterMinistry <strong>of</strong> Agriculture and Food SecurityP.O. Box 44Domasi, MalawiTel: +265 1 536 203/321/460;+265 09 695 203 (M)Fax: +265 1 536 274E-mail: nac@sdnp.org.mw;nationalaquaculturecentre@yahoo.com;brino_chirwa@yahoo.comNETHERLANDSIr. Willy FleurenFleuren & Nooijen Viskwekerij B.V.Jodenpeeldreef 25764RL De Rips, The NetherlandsTel: +31 493 599554; 651 208010Fax: +31 493 599543E-mail: w.fleuren@fleuren-nooijen.nl;willyfleuren@hotmail.comNIGERIABabatunde OlaosebikanFederal College <strong>of</strong> Freshwater FisheriesTechnologyP.M.B. 1500, New Bussa913003, Niger State, NigeriaTel: +234 805 4408417E-mail: badolax@yahoo.comDr. Stella WilliamsDept <strong>of</strong> Agricultural EconomicsObafemi Awolowo University, Ile-IfeOsun State, NigeriaTel: +234 802 8532468; +234 8059312537; +234 806 5296561; +234 8033231076Fax: +234 14713697E-mail: swilliam@oauife.edu.ng; aquabola@hotmail.com; stella_williams0@yahoo.comFelix Olusegun GboladeM.D. Felimar Aquaculture CentrePMB 2134, Ijebu-OdeOgun State, NigeriaTel: +234 803 3443508, 803 6677903E-mail: felimaraqua1@yahoo.comAlex Futson AnpeM.D /CEO Highland Fisheries andAquaculture ServicesP.O. Box 7326 - JOS, Plateau State,Nigeria.Tel: +234 803 7208607, 803 6212169;803 7208607E-mail: Alexanpe12@yahoo.comMrs. Adenike Oluranti Adeleke3, Kumasi CrescentOff Aminu Kano CrescentWuse II, Abuja, NigeriaOffice: Federal Department <strong>of</strong> FisheriesArea 11, Garki AbujaFederal Ministry <strong>of</strong> Agriculture, NigeriaTel: +234 803 7272683; 805 9606873E-mail: rantiadeleke2005@yahoo.comPr<strong>of</strong>. Oyedapo Adewale FagbenroDepartment <strong>of</strong> Fisheries and WildlifeFederal University <strong>of</strong> TechnologyPMB 704 AkureOndo State, NigeriaTel: +234 807 7788688; +234 808 5198441E-mail: dapo_fagbenro@yahoo.co.uk

118 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSSunday OlayinkaObafemi Awolowo Universitylle-lfeOsun StateNigeriaTel: +234 803 371 1533E-mail: wetindey27@yahoo.comAkintunde Israel OyedejiObafemi Awolowo Universitylle-lfeOsun StateNigeriaTel: + 234 803 444 5177E-mail: tundeoyedeji@yahoo.comMathew Oluwafemi OjeladeIbadanOyo StateNigeriaTel: +234 803 5792435E-mail: vemcro@yahoo.comSOUTH AFRICAPr<strong>of</strong>. Danie BrinkDivision <strong>of</strong> AquacultureDept. <strong>of</strong> Genetics, Faculty <strong>of</strong> Agri-SciencesStellenbosch University, South AfricaTel: +27 21 808 5838; +27 855 41114E-mail: db@sun.ac.zaUGANDAMatthew Tenywa MwanjaKyambogo University, Faculty <strong>of</strong> ScienceDepartment <strong>of</strong> Chemistry and BiochemistryP.O. Box 7181, Kyambago, Kampala,UgandaTel: +256 41 287347; +256 41 531918(Res); +256 77 2403186 (M)E-mail: mmtenywa@hotmail.comDavid Semu MatsikoAquaculture Research and DevelopmentCenterP.O. Box 530 Kajjansi, UgandaTel: +256 78 2672433 (M)E-mail: smatsiko2002@yahoo.co.ukWORLDFISH STAFF(ORGANIZERS)Dr. Raul W. PonzoniGeneticist & Project LeaderThe WorldFish Center, Jalan Batu MaungBatu Maung, Bayan Lepas11960, PenangMalaysiaTel: +604 626 1606; 620 2159Fax: +604 626 5530E-mail: r.ponzoni@cgiar.orgDr. Nguyen Hong NguyenScientistThe WorldFish Center, Jalan Batu MaungBatu Maung, Bayan Lepas11960, PenangMalaysiaTel: +604 626 1606; 6202 158Fax: +604 626 5530E-mail: n.nguyen@cgiar.orgChew Guat KhimDiscipline AssociateThe WorldFish Center, Jalan Batu MaungBatu Maung, Bayan Lepas11960, PenangMalaysiaTel: +604 626 1606; 6202 186Fax: +604 626 5530E-mail: g.chew@cgiar.org

WORKSHOP PROGRAM 119ANNEX BWORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENTPROGRAM FOR CATFISH – CLARIAS GARIEPINUSMiklin Hotel, Accra, Ghana5th to 9th November 2007<strong>Workshop</strong> Program4th November Arrival <strong>of</strong> participantsDay 1 ~ 5th November (Monday)0800 - 0900 Registration0900 - 0930 Welcome Address Dr. Yaw Opoku Ankomah0930 - 0945 Introduction to the workshop, housekeeping rules Dr. Raul Ponzoni0945 - 1000 C<strong>of</strong>fee/tea break1000 - 1030 Country report: Ghana1030 - 1100 Country report: Kenya1100 - 1130 Country report: Malawi1130 - 1200 Country report: Namibia1200 - 1330 Lunch1400 - 14301430 - 15001500 - 1515 C<strong>of</strong>fee/tea break1515 - 1545 Nigeria1545 - 1615 South Africa1615 - 1645 UgandaCatfish – World distribution, taxonomy and biology Dr. Randall Brummett<strong>of</strong> the species, conservation issues1645 - 1715 Wrap up for the dayDay 2 ~ 6th November (Tuesday)0830 - 1000 Catfish reproductive management and grow out Ir. Willy Fleuren1000 - 1015 C<strong>of</strong>fee/tea break1015 - 1130 Catfish nutrition and feeds Dr. Sheenan Harpaz1130 - 1230 Clarias in aquaculture: pros and cons Dr. Randall Brummett1230 - 1330 Lunch1330 - 1500 The application <strong>of</strong> genetic principles to catfish genetic Dr. Raul Ponzoniimprovement programs1500 - 1515 C<strong>of</strong>fee/tea break1515 - 1630 WorldFish’s genetic improvement program Dr. Mahmoud Rezkin Abbassa, Egypt1630 - 1700 Catfish molecular genetics – state <strong>of</strong> the art Dr. Nguyen Hong Nguyen1700 - 1730 Wrap up for the day Dr. Raul PonzoniDay 3 ~ 7th November (Wednesday)Field trip

120 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSDay 4 ~ 8th November (Thursday)0830 - 0900 Group work – Introduction and assignment to groups Dr. Raul Ponzoni0900 - 1000 Work in groups1000 - 1020 C<strong>of</strong>fee/tea break1020 - 1230 Work in groups1230 - 1330 Lunch1300 - 1530 Work in groups1530 - 1545 C<strong>of</strong>fee/tea break1545 - 1745 Presentation <strong>of</strong> outcomes from work in groupsDay 5 ~ 9th November (Friday)0830 - 1000 Presentation <strong>of</strong> unified report1000 - 1020 C<strong>of</strong>fee/tea break1020 - 1200 Final debate and refinement <strong>of</strong> recommendations1200 - 1230 Close <strong>of</strong> workshop1230 - 1400 Lunch1400 Participants depart at their own convenience

OPENING STATEMENT AND WELCOME ADDRESS FROM THE DIRECTOR OF CSIR-WRI, DR. YAW OPOKU-ANKOMAH 121ANNEX COPENING STATEMENT AND WELCOME ADDRESS FROM THEDIRECTOR OF CSIR-WRI, DR. YAW OPOKU-ANKOMAHMr. Chairman, distinguished invited guests,members <strong>of</strong> the media, fellow scientists,ladies and gentlemen. It is with muchpleasure that I make this opening statementat the <strong>Workshop</strong> on Development <strong>of</strong> aGenetic Improvement Program for Catfish –Clarias gariepinus scheduled from today, 5 thto 9 th November 2007 at the Miklin Hotel,Accra.On behalf <strong>of</strong> the Director General and onmy own behalf, it is my honor to welcomeyou all to the Council for Scientific andIndustrial Research (CSIR) and, in particular,to its Water Research Institute (WRI).Mr. Chairman, permit me to make a fewcomments about the co-organizing Instituteto our guests.The CSIR-Water Research Institute (WRI)is one <strong>of</strong> 13 research institutions <strong>of</strong> theCSIR. (It was formed in 1996 by mergingthe erstwhile Institute <strong>of</strong> Aquatic Biology(IAB) and the Water Resources ResearchInstitute (WRRI), both <strong>of</strong> the CSIR). TheCSIR-WRI has the mandate to undertakeresearch on all aspects <strong>of</strong> water resources<strong>of</strong> Ghana in order to provide scientific andtechnical information and services neededfor the sustainable development, utilizationand management <strong>of</strong> the resources insupport <strong>of</strong> socioeconomic development <strong>of</strong>the country.The long-term key objectives <strong>of</strong> the Instituteare to:• Generate information and provideservices and appropriate technologiesfor the sustainable development <strong>of</strong>surface water resources <strong>of</strong> Ghana;• Generate, process and disseminateinformation on the amount <strong>of</strong> potablewater that can be abstracted fromgroundwater and the reliability <strong>of</strong> itsrecharge;• Generate, process and disseminate waterand wastewater quality information toend-users;• Enhance public health status throughsound environmental management andwater pollution control strategies;• Increase fish production throughaquaculture development and sustainablemanagement strategies in inland andcoastal waters <strong>of</strong> Ghana; and• Promote commercialization efforts andstrengthen capacity through the provision<strong>of</strong> water resources informationdocumentation and technical supportservices.The objectives stated above are achievedthrough six technical divisions <strong>of</strong> WRI,namely: Surface Water Division; GroundWater Division; Environmental ChemistryDivision; Environmental Biology andHealth Division, Fishery Division, andCommercialization/Information Division(CID).Mr. Chairman, the CSIR-WRI has a longhistory in the area <strong>of</strong> collaborative researchwith the WorldFish Center that dates backto the early eighties when it was known asthe International Center for Living AquaticResources Management (ICLARM). Inthose days, CSIR-WRI was actively involvedin the collection <strong>of</strong> tilapia germplasmfor the famous research that resulted inthe production <strong>of</strong> the fast-growing GIFTtilapia. This was followed by quantitativegenetic work at the Aquaculture Researchand Development Center (ARDEC),Akosombo, aimed at improving the growthrate <strong>of</strong> the local indigenous Nile tilapia(Oreochromis niloticus) under the auspices<strong>of</strong> the International Network on Geneticsin Aquaculture (INGA). This collaborativework has been going on for the past sevenyears.

122 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSThese research efforts are yieldinggreat dividends for the socioeconomicdevelopment <strong>of</strong> the country. Mr. Chairman,I hope the current efforts will hasten theprocess <strong>of</strong> national developments.I take this opportunity to express my deepappreciation and thanks to the WorldFishCenter for this highly successful partnership.I would also like to thank the organizers for allthe toil to get this workshop to a successfulstart. Mr. Chairman, distinguished guests,ladies and gentlemen, once again Iwelcome you to the workshop and wish youa successful and fruitful deliberation.Thank you.

SPEECH OF DR. KWAME BOA-AMPONSEM, FORMER DEPUTY DIRECTOR GENERAL OF CSIR 123ANNEX DSPEECH OF DR. KWAME BOA-AMPONSEM, FORMERDEPUTY DIRECTOR GENERAL OF CSIRDirector <strong>of</strong> CSIR-WRI, project coordinator, fellow scientists, invited participants,I feel honored to have been invited to playa role in this all-important workshop. I wishto express my appreciation <strong>of</strong> the choice <strong>of</strong>Ghana as the venue for this workshop. It isevidence <strong>of</strong> the fact that the quality <strong>of</strong> work<strong>of</strong> fisheries scientists <strong>of</strong> the CSIR-WaterResearch Institute has caught the attention<strong>of</strong> the international scientific community.I salute the Director and scientists <strong>of</strong> theInstitute.In the face <strong>of</strong> dwindling fish resources fromthe sea and other water bodies, the realmeans <strong>of</strong> enhancing production levels isthrough fish farming. However, it is knownthat the quantity <strong>of</strong> fish produced per unitarea <strong>of</strong> pond per cycle is about 2.5 tonnes/ha and has remained the same since 2002(GPRS II, November, 2005). This trendindicates that technology available is notbeing adopted by our fish farmers, or thatmore incisive technology is required toimprove the productivity <strong>of</strong> pond farming.Distinguished participants, productivity <strong>of</strong>fish can be enhanced biologically by threeprincipal means: genetics, nutrition and pondmanagement. Of these, genetic improvementis the only means that is permanent, and canbe passed on from generation to generation.Quantitative genetics is a very powerful toolin breed improvement that has been usedsuccessfully to reduce the maturity period <strong>of</strong>broiler chickens from 18 weeks to 6 weeks. Inthis regards, the achievement <strong>of</strong> Dr. Attipoe´steam at the Water Research Institute inthe improvement <strong>of</strong> Nile tilapia has beendocumented in “Agricultural Technologies2001-2006” published by CSIR. It certainlywill enhance the competitiveness <strong>of</strong> theindustry in Ghana.It is reassuring to note that this workshopseeks to extend the application <strong>of</strong> quantitativegenetic theory to improve catfish, which willgive fish farming a further boost.Judging from the program details <strong>of</strong> thisworkshop, I have no doubt that this is goingto be a very productive week. I wish you welland may God bless your efforts.Thank you.

124 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSANNEX EFORMAT FOR GROUP DISCUSSIONS AND PRESENTATIONThe discussion groups are supposed toidentify the problems and the actions to betaken to address them. The discussionsshould culminate in recommendationsregarding proposed work. Theserecommendations will then be usedto persuade donors and governmentsabout the worthiness <strong>of</strong> the work to beundertaken.PROPOSED FORMAT:OBJECTIVESStatement <strong>of</strong> purpose (i.e. what the projectaims to do, how things will change as aresult <strong>of</strong> the project). What this projectspecifically will do; we need two or threestatements that let the listener or readerknow precisely what this project is about,so that he or she can decide whether theproject is worthwhile.THE PROBLEMWhat is the problem we are addressing?Briefly describe the problem to beaddressed, its nature, its importance, thesize <strong>of</strong> the problem, and general questionsthat will guide the research, developmentand technology transfer process. The sizerelates to relevance and magnitude <strong>of</strong> theproblem globally or regionally. Give anindication <strong>of</strong> what has been done to addressthe problem, if anything (e.g., other projects,approaches, studies that have also identifiedthis as an issue). If nothing or very little hasbeen done, say so.JUSTIFICATION AND OUTPUTSHow will this project contribute to solvingthe problem? Why is this project necessaryor important? To whom is it important? Howwill the countries involved benefit as a result<strong>of</strong> the project? What is the demand forthis project? (Ideally, this reflects demandexpressed by the potential beneficiaries.)What original contribution do the proposedresearch, development and technologytransfer make? What are the outcomesor outputs sought from conducting theproject? In case there is already other workgoing on in this area, how does this projectleverage existing work, in particular projectsfunded by investor organizations we may betargeting.Note: The outputs are the results that theproject seeks to achieve. Try to indicateoutputs as a numbered list. The outputsshould, as much as possible relate to“tangible products” (quantifiable, qualitativeor verifiable) from the conduct <strong>of</strong> theresearch, development and technologytransfer activities undertaken. Try to setmilestones, but not just those that consist<strong>of</strong> reports, frameworks or plans; try to relatethem to real work with water, animals andpeople.APPROACH AND ACTIVITIESThe approach is the conceptualization <strong>of</strong> theactivities to be conducted in the context <strong>of</strong>the research, development and technologytransfer to be undertaken. This sectionshould include a brief overview <strong>of</strong> the type<strong>of</strong> methodology to be employed. The kind<strong>of</strong> data that are required for successfulimplementation needs to be mentioned (e.g.,number and nature <strong>of</strong> genetic improvementprograms to be established, populations tobe sampled to establish a base populationfor the genetic improvement program,choice <strong>of</strong> regions for on farm trials, numberand size <strong>of</strong> hatcheries to be involved in thedissemination <strong>of</strong> the improved strain(s)).This gives an informed listener or reader anoverview <strong>of</strong> the feasibility and likely cost <strong>of</strong>the project. Give a list <strong>of</strong> the specific activitiesthat are likely to result in deliverables thatwill impact the potential beneficiaries. Some

FORMAT FOR GROUP DISCUSSIONS AND PRESENTATION 125donors want budgets by activity area so thatthey can better match inputs to outputs. Theactivities should follow logically and theirtiming should be given (typically in monthsafter project inception).PROJECT LOCATIONIndicate where the research will be carriedout (e.g., regions, countries, productionsystems). This is very important. It maybe wise to initially establish a program incountries that are currently best placed torun it successfully, and gradually integrateother countries as the project evolves andcapacity building progresses.NEED FOR CAPACITYSTRENGTHENINGIdentify capacity building needs and ways toimprove that capacity in the context <strong>of</strong> thepresent project (e.g., what exactly are wegoing to do, run training courses at variouslevels, how many field days, etc.). Whencollaborators (institutions) are involved,indicate what their contributions are. Majorcollaborators will include universities,advanced research institutes, NARS. Indicatethe qualifications and appropriateness<strong>of</strong> collaborators to do this work, and howthis project will strengthen the capacity <strong>of</strong>national and regional institutions to addressthis sort <strong>of</strong> problem.BENEFICIARIES AND STRATEGYFOR IMPACTHow will the project ensure that outputshave impact, and who (beneficiaries) willbenefit, when and how? How will theoutputs <strong>of</strong> the project be disseminated totarget beneficiaries? Distinguish betweenthe immediate impact <strong>of</strong> research (end <strong>of</strong>project situation) and the longer-term result.What things beyond the project’s controlmight prevent or enhance impact?DURATIONAllocate the number <strong>of</strong> years. Perhaps definephases <strong>of</strong> implementation (e.g., establish thebase population in an initial phase, initiate theselection program, survey hatcheries, planon farm testing, whereas in a later phase wemay be in a position to actually disseminateimproved catfish, accredit hatcheries, andsurvey farmers using the improved fish).BUDGETIdeally, this section should reflect the totalbudget to implement the project, and shouldgive an indication <strong>of</strong> the financing strategy.It should indicate what the total budget is,and what the contribution from each one<strong>of</strong> the participating partners will be, as wellas what amount any particular donor isrequested to fund. For the present purpose,we will not develop a detailed budget, butjust an approximate round figure with limitedbreakdown into components.

126 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSANNEX FCONCEPT NOTEINCREASING FOOD PRODUCTION AND ENHANCING NUTRITION SECURITY INAFRICA THROUGH THE DEVELOPMENT AND DISTRIBUTION OF IMPROVEDAFRICAN CATFISH (CLARIAS GARIEPINUS) STRAINSEXECUTIVE SUMMARYFrom an estimated 542 million, thepopulation <strong>of</strong> sub-Saharan Africa (SSA)is projected to increase to 852 million in2015 and to 1143 million in 2030. Meetingthe food and livelihood requirements <strong>of</strong> apopulation growing at such a rate posessignificant challenges to all SSA countries,where virtually no progress has been madein recent decades in relation to increasingfood consumption per head or in povertyalleviation in general. Nevertheless, Africahas a great potential for aquaculturedevelopment, with about 40 per cent <strong>of</strong>its surface area suitable for some form <strong>of</strong>fish farming. The majority <strong>of</strong> SSA countrieshave identified aquaculture as a means <strong>of</strong>increasing food production and alleviatingpoverty, but with the exception <strong>of</strong> Nigeria,production remains low in all <strong>of</strong> them.Catfish are native to Africa; they are widelysought after as food by the population andconstitute a very valuable source <strong>of</strong> protein.The development <strong>of</strong> improved catfishstrains and the application <strong>of</strong> “best practice”aquaculture techniques that are compatiblewith available resources and sustainableover time can result in 70 percent increasesin production.The government departments responsiblefor primary production in the countriesselected for this project have identifiedaquaculture development as one <strong>of</strong> themeans <strong>of</strong> ensuring food security in sectors<strong>of</strong> the population. Catfish were chosenas the preferred species for the presentproject. They have a number <strong>of</strong> attributesthat make them especially suitable forculture (hardiness, flexible feeding habitand requirements, potential to produce twocrops per year, ability to be raised in polyculture)and they are highly accepted fishamong consumers. The most salient projectoutputs will be:1.2.3.4.5.6.National selective breeding programsfor the production <strong>of</strong> high quality catfishseed consolidated or established in theparticipating countries.Multiplication and disseminationstrategies for the improved strainsdeveloped and implemented throughboth government and private hatcheriesas deemed appropriate in each specificcircumstance.<strong>Workshop</strong>s and training sessions forcapacity building <strong>of</strong> NARS’ staff, privatehatchery operators and farmers.Enhanced capacity in the governmentand private sectors to produce,distribute and utilize improved catfishstrains as well as other aquaculturespecies <strong>of</strong> interest.Increased food production due tobetter aquaculture practices and use <strong>of</strong>improved strains.Impact on nutritional status and income<strong>of</strong> target groups.The present project will build andcapitalize on an earlier one called “Transfer<strong>of</strong> selective breeding technology foraquaculture improvement from Asia tosub-Saharan Africa and Egypt – PhasesI and II”, funded by the Japanese HumanResources Development Fund throughthe UNDP Special Unit for South to SouthCooperation. The models developed andexperience accumulated in the areas <strong>of</strong>genetic improvement and distribution <strong>of</strong>improved seed in Ghana and Malawi willbe applied to catfish in Cameroon, Egypt,Ghana, Kenya, Malawi, Nigeria and Uganda,in what will be an example <strong>of</strong> South to Southcooperation.The WorldFish Center has a successful trackrecord in the areas <strong>of</strong> developing improvedstrains <strong>of</strong> fish (Genetically Improved FarmedTilapia, GIFT project) and <strong>of</strong> aquacultureproduction projects (Integrated Agriculture-

(UNIFIED REPORT) CONCEPT NOTE 127Aquaculture, IAA). Furthermore, its staffmembers are well recognized worldwide fortheir achievements in the field.The project will be carried out over a period<strong>of</strong> five years. The total project cost hasbeen estimated at US$1.0 to 1.3 million perbreeding center established.THE PROBLEMWild capture fisheries are dwindling,leading to economic declines in fishingcommunities and rapidly increasing scarcity<strong>of</strong> fish for human consumption. In general,rural communities are poor and needalternatives to diversify their economy as ameans to reduce poverty and increase thequantity and enhance the quality <strong>of</strong> localfood supplies. Aquaculture has been shownto be capable <strong>of</strong> directly addressing theseproblems, but it is widely constrained by thelack <strong>of</strong> high quality fingerlings, the problemthat is exacerbated by weak nationalaquaculture research, development andextension programs. There are no Africancatfish improved strains available at present,and cultured stock exhibits low productivityquite likely due to inbreeding.OBJECTIVESGENERAL• To improve the availability <strong>of</strong> high-qualitycatfish seed to fish farmers• To build local capacity at the levels <strong>of</strong>producer, hatchery manager and NAREStechnical staff in the area <strong>of</strong> geneticresource managementSPECIFIC OBJECTIVES:• Develop improved strains <strong>of</strong> catfish withcharacteristics <strong>of</strong> increased growth rateto market size and improved survival inculture; in future, the improvement <strong>of</strong>other traits such as disease resistanceand temperature tolerance, may also bepursued• Improve on-farm and hatchery broodstock management to eliminate problemsdue to inbreeding and to poormanagement <strong>of</strong> the genetic resource• Improve the access to knowledge aboutbrood stock management to farmers• Strengthen regional inter-centercollaboration and capacity in fish geneticresource managementJUSTIFICATIONAND OUTPUTSAquaculture <strong>of</strong>fers an option to increasefood production. In a number <strong>of</strong> countries,it is already having a strong positive impacton economic growth and food security.In much <strong>of</strong> Africa, aquaculture in generaland catfish farming in particular, has arecognized potential to generate revenues,create jobs, diversify local economiesand increase local, national and regionalfish supplies. Demonstrated successesin Egypt and Nigeria have resulted inpr<strong>of</strong>itable technological models (e.g. marketweights <strong>of</strong> 600-700 g in 6 months; 1.5 kgin 12-15 months), and developed a pool<strong>of</strong> trained technicians within the region.However, productivity and pr<strong>of</strong>itability arecompromised by a lack <strong>of</strong> high quality seedand <strong>of</strong> adequate feeds at an affordable price,and by limited market development andprocessing facilities. With up to 40 percentdeclines in the growth rate attributable topoor genetic quality <strong>of</strong> farmed stocks, thesupply <strong>of</strong> high quality fingerlings has beenprioritized as one <strong>of</strong> the key constraints toaquaculture expansion in most countries.C. gariepinus production in West/Central (W/C)and East/Southern (E/S) Africa (FAO 2005);fr = Francophone, gb = AnglophoneCountry Sub-Region MT 1000 USDBenin* W/C (fr) 30 68.4Burkina Faso W/C (fr) 1 1Cameroon* W/C (fr/gb) 110 313.5D.R. Congo W/C (fr) 6 21Ghana* W/C (gb) 1,510 2,416Kenya** E/S (gb) 318 1,052.6Malawi* E/S (gb) 21 27.3Mali* W/C (fr) 300 300Nigeria** W/C (gb) 20,413 65,321.6Rwanda E/S (gb) 16 17.3South Africa* E/S (gb) 100 252.2Zimbabwe E/S (gb) 2 4Total 22,827 69,794.9* high priority countries, ** sub-regional centers

128 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSNevertheless, existing government effortsto create a facilitating environment toalleviate this problem are not addressingkey relevant issues in the improvement<strong>of</strong> the genetic quality <strong>of</strong> the stocks beingfarmed. Considering: 1) the wide indigenousdistribution <strong>of</strong> catfish (hence avoiding therisks associated with the introduction <strong>of</strong> alienspecies), 2) that most national programs arelacking in capacity in selective breedingand genetic resource management, andthat 3) expertise is available in Egypt andNigeria, a regional approach appears asmost appropriate for addressing problems<strong>of</strong> genetic quality <strong>of</strong> farmed catfish stocks.OUTPUTS• Up to three sub-regional catfish geneticimprovement programs with at least onestrain each available for distribution tothe private sector• Approximately 20 percent improvementin catfish supplies for human consumptionin the short term• Proportional growth in revenues,employment and productivity throughoutthe aquaculture value chain, includingproducers, transporters, wholesalers,retailers, feed producers and processors• Strengthened capacity in the management<strong>of</strong> genetic resources among producers,hatchery managers and NARES.APPROACH AND ACTIVITIESSub-regional breeding centers (in West/Central, Eastern and Southern Africa) linkedto a research and training facility at Abbassa(Egypt) in North Africa, will establish andimplement genetic improvement programsto develop one or more improved lines <strong>of</strong>Clarias gariepinus for use within each subregion.Effective seed multiplication anddistribution systems will be developed,national demand-driven Public-PrivatePartnerships (PPP) will be used to strengthenthe brood stock management capacity <strong>of</strong>SME aquaculture investments, especiallyprivate hatcheries, through a series <strong>of</strong>national workshops, seminars and trainingcourses.ACTIVITIES• Establish the physical infrastructurerequired to undertake selective breeding<strong>of</strong> catfish.• Conduct regional training (takingadvantage <strong>of</strong> existing expertise in Egypt,Nigeria and South Africa) to addresshuman resource needs in selectivebreeding and brood stock management.• Survey and characterize for bothaquaculture and conservation purposes,available wild and farmed populations <strong>of</strong>C. gariepinus.• Establish sub-regional brood fishpopulations for use in selective breeding.• Determine, through research, appropriatebreeding system methodology.• Implement appropriate selective breedingprograms for West-Central, Eastern andSouthern Africa.• Develop PPP training programs in majorcatfish producing countries in each subregionto improve private sector hatcherycapacity in brood stock management.• Undertake a series <strong>of</strong> promotionalactivities on the use and management <strong>of</strong>improved seed, including a regionalproducers’ symposium and trade show.PROJECT IMPLEMENTATIONLOCATIONThe project is envisioned to be implementedthrough a network <strong>of</strong> existing sub-regionalcenters. Egypt is seen as primarily a sitefor training and methodological research.The Nigerian private sector possessesconsiderable know-how on practicalproduction technology. These two sources<strong>of</strong> expertise would be connected throughtraining and capacity building to one or moresub-regional selective breeding centersfrom which improved brood stock would bedeveloped and distributed throughout theirrespective sub-regions.The WorldFish Regional Center forAquaculture at Abbassa, Egypt is envisagedprimarily as a training center and researchsite for the development <strong>of</strong> improvedbreeding technology for application at theother centers.

(UNIFIED REPORT) CONCEPT NOTE 129CAPACITY STRENGTHENINGWhile taking advantage <strong>of</strong> existinginfrastructure as much as possible,upgrading, expanding and equipping basicbreeding facilities will be necessary at thesub-regional breeding center(s).Human resources within the region have tobe substantially strengthened. Training isthus envisioned for: 1) selective breedingtheory and methodology for senior NARESresearchers at each sub-regional center; 2)catfish hatchery management and growouttechnology for breeding staff andtechnicians engaged directly in the subregionalbreeding programs, conducted inNigeria; and 3) brood stock management forsub-regional outreach personnel conductedat sub-regional center(s).Training in selective breeding approaches,monitoring and reporting will be conductedfor two senior technicians at the WorldFish-Egypt center to build the human resourcesneeded to implement the breedingprograms.Basic skills for catfish breeding go beyondbrood stock management and breedingtheory to include induced spawning, larvalrearing, fingerling production and grow-out.Basing the selective breeding protocols onthe prevailing production system(s) withinthe sub-region will help avoid problems <strong>of</strong>genotype by environment (GxE) interactionsand ensure that improved strains can beeasily adapted to the prevailing productionsystems. A training program in brood stockmanagement and basic catfish productionprotocols for three project technicians fromeach sub-regional center will be conductedin Nigeria by WorldFish in close collaborationwith Nigerian catfish farmers and NARES.To enhance brood stock management skillsoutside the sub-regional centers and int<strong>of</strong>arms throughout each sub-region, severaltraining <strong>of</strong> trainers (TOT) programs will beconducted at the sub-regional centers (3countries x 2 persons per country x 2 cycles= a total <strong>of</strong> 12).These latter courses require a modest budgetto develop the necessary base <strong>of</strong> expertiseneeded to train SME hatchery managers ineach catfish producing country within thesub-region. Also, a series (usually 3 peryear over 5 years = 15) <strong>of</strong> national seminars,on-farm trials, field-days and exchangevisits will be conducted. This would create afavorable environment for the establishment<strong>of</strong> a good working arrangement with subregionalprivate catfish hatcheries in Public-Private Partnerships (PPP) that can manage,disseminate and maintain the quality <strong>of</strong>improved seed obtained from the subregionalbreeding program.PHASING IN, DURATION ANDBUDGETThere are several options for phasing in theoverall project implementation. There areindications, for example, that C. gariepinuspopulations vary to a certain extent overthe total <strong>of</strong> their range and that in West-Central and East-Southern Africa differentstocks are represented. It might then bereasonable to phase in the activities by subregion.However, this will be dictated by theperceived urgency <strong>of</strong> the problem in eachsub-region and the availability <strong>of</strong> funds.In any case, the initial step is to establishwell designed base populations, from whichimproved strains can be developed throughselective breeding. As described in thisconcept note, capacity-building activitiesconstitute an integral part <strong>of</strong> the project.Initially, activities will focus on the needs<strong>of</strong> national programs to begin and executeimproved catfish genetic management attwo key levels: 1) selective breeding onstation,and 2) brood stock management atlocal hatcheries.Preliminary budget estimates indicate thatthe cost per breeding center for a five yearproject would be <strong>of</strong> the order <strong>of</strong> US$1.0 to1.3 million.BENEFICIARIESAND IMPACTIn order to solve a fundamental problem inregional aquaculture, replacing existing poorquality farmed stocks and improving broodstock management in farms and hatcheriesare essential to benefit a broad range <strong>of</strong>

130 PROCEEDINGS OF THE WORKSHOP ON THE DEVELOPMENT OF A GENETIC IMPROVEMENT PROGRAM FOR AFRICAN CATFISH CLARIAS GARIEPINUSplayers throughout the aquaculture valuechain, including producers, transporters,wholesalers, retailers, feed producersand processors. Two areas <strong>of</strong> impact areforeseen:1.2.Short term increases <strong>of</strong> 20-30 percentin growth rate based on improvedbrood stock management on existinghatcheries and vertically integratedfarms, andLonger-term, sustained improvementsin fish farm productivity in the order <strong>of</strong>50 to 60 percent based on the use <strong>of</strong>faster-growing strains <strong>of</strong> catfish.Increases <strong>of</strong> this magnitude will raiseregional catfish production by an estimated20 thousand tonnes per annum with anapproximate wholesale value <strong>of</strong> US$55million only on existing farms. Increasingthe competitiveness and economicattractiveness <strong>of</strong> catfish farming willencourage new entrants to fish farming.With about half <strong>of</strong> the retail value <strong>of</strong> thefish produced in aquaculture accruing toenterprises that are not directly involvedin fish production, substantial increases inemployment and income generation overthe entire value chain are envisaged.