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Fungal examinationFungal infection is commonly found when the water temperature drops down and fish encounter with some healthproblem such as injury, parasite manifestation and bacterial infection. The clinical sign can be easily seen ascotton-like growing on the skin, which can cover large area. This external fungus mostly belongs to Saprolegniasp.Epizootic ulcerative syndrome (EUS) is an internal fungal disease caused by Aphanomyces invadans. Infectedfish typically show necrotic dermal ulcers and mortality is reasonably high. Confirmatory is usually done byhistopathology to demonstrate mycotic granulomas and invasive hyphae. Fungal isolation can be done foridentification purpose.Bacteriological examinationGross clinical signs can be observed as a presumptive diagnosis, however some infected fish may not reveal anyclinical signs until the infection become well-advanced stage. These clinical signs are including:• abdominal distension (dropsy)• exophthalmia (pop-eye)• scale protrusion• haemorrhagic lesion on skin, fin, eye, and internal organs• enlargement of internal organs• discolouration of skin and internal organs• abscess or granuloma on skin or internal organsConfirmatory should be done by the diagnostic laboratory. This includes bacterial culture, biochemistry test, andsome advanced techniques may also be applied to speciate the bacterial species.Virological examinationViral diseases caused by a wide range of virus and each disease shows different clinical signs. Some are uniqueto the disease, while some are commonly found in other pathogen infection. However, viral disease is commonlyreported as host specific infection. This may narrow the host range for presumptive diagnosis.Confirmatory is mainly done by viral isolation which requires a specific cell line. This poses a difficulty to someviral diseases when the cell line is not available, particular to shrimp viral diseases. By this means, DNA-basedtechniques are commonly adopted. Along with viral isolation, histopathology is also applied to investigate theevidence of viral infection. Further confirmation can be done by transmission electron microscopy (TEM) of ultrathinsection of infected tissue to reveal viral particles.Advance diagnostic techniquesEnzyme-linked immunosorbent assay (ELISA)ELISA is one of antibody-based techniques originally developed for the analysis of murine antibodies and someyears later it was adapted for trout antibody affinity analysis. ELISA has extensively been studied for both immuneresponse of fish and diagnosis of their diseases as it has been known for a rapid and sensitive method.ELISA can be performed with four variations; the assay can be done in antibody excess, in antigen excess, asantibody competition, or as antigen competition. Assay done in antibody excess or as antigen competitions areused to detect and quantitate antigens, while antigen excess or antibody competition assays are used to detectand quantitate antibodies.51
In principle, the only factors that need to be considered in choosing the correct design of an immunoassay are thetypes of antibodies that are available (polyclonal antibodies, monoclonal antibodies, a single or two or moremonoclonal antibodies) and whether pure or impure antigen is available.Polymerase chain reactionPCR is a technique for the in vitro amplification of specific DNA sequences by the simultaneous primer extensionof complementary strands of DNA. The reaction composes with three steps including: denaturation, annealingand extension. The final products or PCR products are subsequently analysed by agarose gel electrophoresis orwith some more advance techniques for further required information.In situ hybridizationIn situ hybridization is a technique for identifying specific nucleic acid sequences (genes) in their cellularenvironment. The probe is oligonucleotide specific to the target DNA of the pathogen/organs. The probes arenormally linked with the signal system, which can be enzymatic system or isotopic system. In final step the linkedsignal is visualized with relevant enzyme/substrate to determine the reaction.Disease prevention strategiesGood farm managementGood farm management is a major part of the disease prevention strategies. Since the infectious agents are allaround in the environment and surrounding wild aquatic animals, farmers should take a number of measures tominimize the disease in their stocks. These measures are including:• screen seed/broodstock for any infectious agents before introducing into the farms• control water source and quality to ensure optimum growing of their animals and reduce exposure topathogens• maintain stocking densities at optimum level• allow time to fallow sites between crops and apply disinfectant to pond/tank and equipment• apply strict hygiene practices including disinfection procedures• avoid equipment movement between different areas of the farms• improve nutrition and diet, and store them in cool, dry, and well-ventilated place to prevent rancid andmoulding• closely monitor the stocks to ensure early detection of disease problemsHealth surveillanceRegular monitoring of fish health is highly recommended to be part of good aquaculture practice. This will assurethe farmer to be aware of the fish health status and any early infection that may occur within their farm. Thesampling size must be well represent the whole population and minimize the overlooking of the early infection.Number of fish samples for the health surveillance purpose is described in Table 1.However, the process of capturing fish can introduce some certain degree of stress to both sampled fish and theentire population. Netting and handling should greatly be taken care and time out of water should be minimized.Anesthetics are also commonly practiced to improve fish survivability and growth post handling.VaccinationVarious types of vaccine are commercially available mainly to the major diseases of economic fish species.Monovalent vaccine is a product to cover only one pathogen strain, whereas the multivalent is aimed to cover a52
Page 1 and 2: Training of TrainersProgramme3-7 Au
Page 3 and 4: Table of Contents1. Preface 42. Sen
Page 5 and 6: knowledge about the activities carr
Page 7 and 8: iosphere, in that it is essentially
Page 10 and 11: Importance in narrowing the supply
Page 12 and 13: Figure 7: The trend in aquaculture
Page 14: aquaculture has been a success thus
Page 17 and 18: pathogen transfer is generally cons
Page 19 and 20: • It highlights the importance a
Page 21 and 22: particular animal are identified, t
Page 23: Knowledge at the bottom of the pyra
Page 26 and 27: farmer innovation process. In this
Page 28 and 29: • Rapport building• Working str
Page 30 and 31: shrimp farming is undertaken in the
Page 32 and 33: Reintjes, C and Hiemstra, W. 1989 F
Page 34 and 35: • An increase in reliable product
Page 36 and 37: Principles of AACC are to: 1) Facil
Page 38 and 39: Maintaining genetic quality of fish
Page 40 and 41: Where F is the percent increase in
Page 42 and 43: o G=(0.95) 1/10G =0.994883803Figure
Page 44 and 45: Aquaculture extension and training
Page 46 and 47: ResearchExtensionFarmersFlow of inf
Page 48 and 49: view of outside world than before a
Page 50 and 51: Along with fish sample, the support
Page 54 and 55: few different pathogen strains. The
Page 56 and 57: Major finfish diseases in Asia and
Page 58 and 59: A great number and diversity of ani
Page 60 and 61: • -oxidase test positive• -resi
Page 62 and 63: ReferencesAustin, B. and D. Austin.
Page 64 and 65: Accessing better markets-improving
Page 66 and 67: Owing to its importance in generati
Page 68 and 69: adopt standards for responsible shr
Page 70: Tokrisna R, Benheam W., 1995. Gain
Page 73 and 74: of the temperature rise that were d
Page 75 and 76: Principles of developing, validatin
Page 77 and 78: 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
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New, M.B., A. G. J. Tacon and I. Cs
Page 109 and 110:
later stages it has become a much m
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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
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NaCSA disseminates BMPs mainly thro
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1. Drain the pond water completely
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Seed transportation and Stocking:
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7. Presently 100% of the society po
Page 129 and 130:
would help in sustaining shrimp sec
Page 131 and 132:
Stress brought about by the capture
Page 133 and 134:
Enhance women participation in aqua
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women in aquaculture and identify a
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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
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Compliance to international standar
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(ii) to protect human or animal lif
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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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