, Diagnosis an-&& of Shrimp Diseases - Central Institute of ...

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Red diseaseThe juveniles and adult shrimps / broodstock affected with red disease have reddishdiscoloration in body, pleopods and gills. Definite causative agent is not known. One of thereasons believed to be the cause of disease is a microbial toxin in rancid or spoiled diets or indetritus of ponds rich in organic matter. Extreme conditions of pH or salinity in pond watermay also cause the disease. Healthy management of ponds along with the use of good qualityfeed may help in the avoidance of red disease.Cramped tail diseaseAffected shrimps have rigid dorsal flexure of the abdomen, which cannot bestraightened. These shrimps lie on their sides at the bottom of the pond and are susceptible tocannibalism. Exact cause for this disease is not known, but environmental and nutritionalcauses have been suggested. Maintenance of healthy conditions in the pond with properfeeding with balanced diet may be helpful in the prevention I control of this disease.Gas-bubble diseaseSuper saturation of atmospheric gases and oxygen in the pond can result in the gasbubbledisease, which affects the shrimps of all sizes. Presence of gas bubble in the gills orunder the cuticle is the characteristic of this disease. Gas bubble disease due to oxygen is notlethal, while that of nitrogen can be lethal. The threshold saturation level to cause the gasbubble,in the case of nitrogen is 118 % while that of oxygen is 250 % of normal saturation.The severely affected or dead shrimp due to this disease may float near the water surface.Super saturation of the gases must be avoided to prevent the disease.Muscle necrosisShrimps of all life stages are affected with muscle necrosis. Affected shrimps arecharacterised by the presence of white opaque areas in body musculature, usually in the lowerabdomen or some times in the appendages. The condition is reversible in the early stages ifthe corrective measures are taken, but in severe cases sloughing of the affected areas occursdue to secondary bacterial infection leading to death. This disease is associated with poorenvironmental conditions such as low oxygen levels, and salinity or temperature shock.Overcrowding and poor handling also can cause muscle necrosis. Avoidance ofovercrowding, proper handling and maintenance of favourabIe environmental factors mayhelp to contain the disease.
INVESTIGATING SHRIMP DISEASES: OBSEliVATION ON POhZ) gL SHRIMPAND SAMPLINGS.V.Alavandi, K.K. Vijayan T.C. Santiago and N. KalaimaniProper and accurate diagnosis of diseases forms the cardinal step in any diseasecontrol and prevention programme.' To diagnose a shrimp disease problem, history of thefarms, the soil and water conditions of the ponds, incidence of any disease problem in theadjoining areas, possibility of disseminating disease through birds or other carriers, are ofgreat importance.These are the significant information related to the epidemiology of thedisease. This section stresses the need to examine general information on the farming activityCand the information regarding disease on site and some points on collection of samples forlaboratory investigation.1. Background information about the farming practicesA. Exnrnirzatio?~ of pondsThis involves the various parameters of ponds such as methods followed in thepreparation of ponds, depth, nature of the bottom, water treatment methods, nature of waterinlet and outlet procedure etc. Apart from these, colour of water, algal blooms, turbidity ofwater and presence of bioluminescence during night are also important criteria, whichdetermine the health of the shrimp.B. Stocking parametersThese parameters include origin and source of seeds, health status of spawners and thelarvae, survival rate of larvae within the hatchery and nursery, whether any antibiotic1disinfectant used for larval rearing; stocking density, time of stocking etc. These parametersare very much important in assuring the healthy or resistant nature of the larvae and in thediagnosis of any possible disease problem.C. Managentent practicesThese include data generated out of the close monitoring of the system for the growth,survival and occurrence of diseases. These also include the quality of the feed, feedingregime, consumption of feed by the shrimp, time and rate of water exchange and the use ofchemicals, immullostimulants or bioremedial measures also to be recorded.D. Environmental parametersDiseases may be of infectious and non-infectious eteologies. Majority of the noninfectiousdiseases are due to nutritional deficiency or due to abnormal environmental
Page 5 and 6: OVERVIEW OF STRATEGIES FOR PREVENTI
Page 7 and 8: in harmonizing aquatic animal healt
Page 9 and 10: SI-IRXMP DISEASES: GENEIL4L ASPECTS
Page 11 and 12: quantitative level of pathogen is i
Page 13 and 14: presence of prominent eosinophiiic
Page 15 and 16: Disease affected the shrimps of all
Page 19 and 20: BACTERIAL AND FUNGAL DISEASES OF SH
Page 21 and 22: Cause: The epibiotic bacteria stich
Page 23 and 24: PARASiTIC AND NON-INFECTIOUS IIISEA
Page 25: XOS-INFECTIOUS DISEASESNon-infectio
Page 29 and 30: lnay be a predisposing factor for b
Page 31 and 32: BACTERIOLOGICAL METHODSS.V. Alavand
Page 34 and 35: In place of ZMA, nutrient agar prep
Page 36 and 37: Interpretation: Positive reaction i
Page 38 and 39: Incubate at 37°C for 1-2 h.Examine
Page 40 and 41: Alkaligens: etc. are resistant. The
Page 42 and 43: Culture Media, Reagents and StainsC
Page 45 and 46: Differential characteristics of Vib
Page 47 and 48: Davidson's Alcohol Formatin Acetic
Page 49 and 50: Paraffin cold impregnationXylene an
Page 51 and 52: ProcedureDe-paraffinise the slid'c
Page 53 and 54: Biochemistry of Nucleic Acids with
Page 55 and 56: DNA e.rl1i6it.v base equivuleizcc!E
Page 57 and 58: hydrolyzed by dilute alkali. The su
Page 59 and 60: Polymerase Chain Reaction (PCR) is
Page 61 and 62: a number of viral, bacterial and pa
Page 63 and 64: from 15-30 bases. Negative controls
Page 65 and 66: PCR Primers for Indian WSVTwo sets
Page 67 and 68: ANTIOXIDANTS IN MANAGEMENT OF OXIDA
Page 69 and 70: Many potent chemical carcinogens ar
Page 71 and 72: cells. It has been shown that possi
Page 73 and 74: AFB, induced ~nutagenesis in Salmon
Page 75 and 76: FIGURE 2. An overview of oxygen rad
Page 77 and 78:
were responsible for production los
Page 79 and 80:
for Asiatic region. The participati
Page 81 and 82:
charge of the DNA fragment. The neg
Page 83 and 84:
European countries have in place th
Page 85:
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, Diagnosis an-&& of Shrimp Diseases - Central Institute of ...

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