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Strategies to produce and distribute quality seedWenresti G. Gallardo, PhDAquaculture and Aquatic Resources Management,School of Environment, Resources and Development,Asian Institute of Technology, Bangkok, ThailandAbstractThis paper presents the strategies to produce and distribute quality seed, based on research findings. Thesestrategies include provision of proper nutrition and management of broodstock, appropriate larviculturetechniques, and effective networking and seed transport methods.IntroductionThe quality of fish seed (fry and fingerlings) has significant effect on the production and income from grow-outculture operations and on the ecosystem if the seed is used for restocking or stock enhancement. Inasmuch aswild fish stocks is declining, research efforts have increased in recent years to develop techniques to artificiallyproduce seed for grow-out culture and stock enhancement purposes. However, in some cases, the quality of seedproduced from captive brood-stock has not been good because the right strategies were not available or followed.One of the objectives of the project in which this training of trainers (ToT), is to improve sustainability of farmingsystems, particularly tilapia culture in cages and ponds in Thailand, shrimp culture in Vietnam, sea bass andgrouper culture in Indonesia, seaweed culture in the Philippines, and snakehead culture in Cambodia.Sustainability of these farming systems would be dependent on the availability of quality seed. The strategiespresented in this paper are based on research findings and would be useful in producing quality fish seed neededfor aquaculture development.Proper nutrition and management of captive broodstockSeed quality is dependent on brood-stock nutrition and management (Izquierdo et al., 2001). Proper brood-stocknutrition is very important because many species decrease food intake during final development of the gametes,making it necessary for the fish to withdraw nutrients and energy for ovarian growth and other functions from itsbody reserves (Zohar et al., 1995), importance of a balanced ratio of n-3/n-6 polyunsaturated fatty acids (PUFA).Specific strategies related to broodstock nutrition and management include:a. Supplementation of diets with marine fish oils rich in n-3 PUFA.Broodstock diets with more vegetable oils rich in 18:2(n-6) will have an effect on egg and larvalquality. Docosahexaenoic acid (22:6n-3; DHA) and eicosapentaenoic acid (20:5n-3; EPA) areessential fatty acids which have important functions in brood-stock diets and eggs (Carillo et al., 2000;Sargent et al. 1995). There should be a balanced ratio of n-3/n-6 polyunsaturated fatty acids (PUFA)in the diet. It has been reported that juveniles of marine species in which the broodfish were fed dietsrich in essential fatty acids produced eggs of significantly enhanced quality compared to controls inred seabream (Watanabe and Kiron, 1995), and the grouper Epinephalus tauvina (Dhert et al., 1991).b. Minimizing stress on the broodfish129
Stress brought about by the capture and holding of broodfish under controlled conditions can affect broodstockreproductive performance and eventually seed quality, thus, broodfish should be kept at low density withsufficient food.c. Reduction of the likelihood of pathogen transfer from the environment and broodstock to seedby:a. Screening of broodstock for bacteria and viruses which can be transferred betweenbroodstock and eggs.b. Isolation of hatchery stocks and location of hatcheries to reduce risk of cross-contaminationby infected and/or feral organisms and/or water sources.c. Disinfection, pre-treatment and recycling of water and quarantine before transfers are all inregular use as disease-prevention methods.d. Development of domesticated stocks that are genetically improved and are free of specificallylisted pathogens (Argue et al., 2002).d. Induction of spawning at optimal periodDue to the requirement of aquaculture producers for seed all-year-round, production of seed outsideof natural seasons have been induced but this also has implications for the quality of seed produced.For example, spawns from early and late-season batches of hybrid catfish (Clarias macrocephalus xC. gariepinus) and carp seed are known to be of poorer quality than those from the main season. Thisvariability has been explained by incomplete maturation and the onset of atresia (Ingthamjitr, 1997).e. Maintenance of genetic qualityInbreeding is a major genetic problem in captive hatchery stocks and it is often identified as a majorcause of quality deterioration. To keep inbreeding rates low (about 1% per generation), a minimum of50 pairs of breeders should be selected and the number of progeny tested should be restricted andstandardized to not less than 30–50 progeny per pair (Bentsen and Olesen (2002).Appropriate larviculture techniquesAnother major cause of poor seed quality is the lack of appropriate techniques for larviculture. Research studieshave provided useful information for the development of appropriate larviculture techniques such as:• Use of microalgae, the rotifer (Brachionus plicatilis) and the brine shrimp (Artemia) as initial feedespecially for marine species of finfish, crustaceans, and mollusks.• Use of algal substitutes in shrimp larviculture and are a key part of ‘green water’ technology used even forcarnivorous fish species. Although the algae do not constitute the major food source for these fish, thisapproach appears to improve results, probably for a variety of reasons (Lavens et al., 1995).• Enrichment of live larval feeds either indirectly by enriching the microalgae themselves or directly byraising rotifers or Artemia on enriched artificial diets. The basis of enrichment is the use of (n-3) HUFA,and especially the correct balance of EPA and DHA. Fish seed produced using these diets show bettersurvival and tolerance of stress.Effective networking and seed transportation130
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Training of TrainersProgramme3-7 Au
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Table of Contents1. Preface 42. Sen
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knowledge about the activities carr
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iosphere, in that it is essentially
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Importance in narrowing the supply
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Figure 7: The trend in aquaculture
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aquaculture has been a success thus
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pathogen transfer is generally cons
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• It highlights the importance a
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particular animal are identified, t
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Knowledge at the bottom of the pyra
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farmer innovation process. In this
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• Rapport building• Working str
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shrimp farming is undertaken in the
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Reintjes, C and Hiemstra, W. 1989 F
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• An increase in reliable product
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Principles of AACC are to: 1) Facil
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Maintaining genetic quality of fish
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Where F is the percent increase in
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o G=(0.95) 1/10G =0.994883803Figure
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Aquaculture extension and training
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ResearchExtensionFarmersFlow of inf
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view of outside world than before a
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Along with fish sample, the support
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Fungal examinationFungal infection
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few different pathogen strains. The
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Major finfish diseases in Asia and
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A great number and diversity of ani
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• -oxidase test positive• -resi
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ReferencesAustin, B. and D. Austin.
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Accessing better markets-improving
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Owing to its importance in generati
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adopt standards for responsible shr
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Tokrisna R, Benheam W., 1995. Gain
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of the temperature rise that were d
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Principles of developing, validatin
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such as determinants, exposures and
Page 79 and 80: How to promote adoption of BMPs?Pro
Page 81 and 82: economic sustainability. BMPs need
Page 83 and 84: Once you understand your stakeholde
Page 85 and 86: As conventional approaches such as
Page 87 and 88: Printed publicationsPrinted publica
Page 89 and 90: Set up a blog or website for your w
Page 91 and 92: If you have a website, all you need
Page 93 and 94: ought about increased profits among
Page 95 and 96: • It is a farming system the prod
Page 97 and 98: Annex 1. The area surveyed for obta
Page 99 and 100: contribute substantially to maintai
Page 101 and 102: seawater, but in fresh water its le
Page 103 and 104: type of ingredients used, since som
Page 105 and 106: This is a new approach used to buil
Page 107 and 108: New, M.B., A. G. J. Tacon and I. Cs
Page 109 and 110: later stages it has become a much m
Page 111 and 112: c. Improved information exchange an
Page 113 and 114: implemented by both societies. Inte
Page 115 and 116: With better informed farmers, the s
Page 117 and 118: According to FAO, it is estimated t
Page 119 and 120: Farmer organization as models for p
Page 121 and 122: NaCSA disseminates BMPs mainly thro
Page 123 and 124: 1. Drain the pond water completely
Page 125 and 126: Seed transportation and Stocking:
Page 127 and 128: 7. Presently 100% of the society po
Page 129: would help in sustaining shrimp sec
Page 133 and 134: Enhance women participation in aqua
Page 135 and 136: women in aquaculture and identify a
Page 137 and 138: major percentage of staff, the need
Page 139 and 140: having more self confidence through
Page 141 and 142: Overall status of men and women in
Page 143 and 144: Compliance to international standar
Page 145 and 146: (ii) to protect human or animal lif
Page 147 and 148: c) FAO/WHO Codex Alimentarius Commi
Page 149 and 150: Annex 1: List of participantsCountr
Page 151 and 152: Annex 2: AgendaDate Time Presentati
Page 153: Annex 3: List of resource persons1.
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