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Abstract:
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The immunostimulatory effect of an alkali insoluble glucan extracted from marine yeast isolate Candida sake
S165 was tested in Fenneropenaeus indicus. Post larvae (PL) of F. indicus, fed glucan incorporated diet at
varying concentrations (0.05, 0.1, 0.2, 0.3, 0.4 g glucan/100 g feed) for 21 days were challenged orally with
white spot syndrome virus (WSSV). Maximum survival was observed in PL fed the 0.2% glucan incorporated
diet. Subsequently the feed incorporated with 0.2% glucan was fed to F. indicus post larvae at different
feeding intervals, i.e. daily, once every two days, once every five days, once every seven days and once every
ten days. After 40 days, the prawns were challenged orally with WSSV and post challenge survival was
recorded. Shrimp feed containing 0.2% glucan when administered once every seven days gave maximum
survival. This was supported by haematological data obtained from adult F. indicus, i.e. total haemocyte count,
phenoloxidase activity and nitroblue tetrazolium reduction (NBT). The present observation confirms the
importance of dose and frequency of administration of immunostimulants in shrimp health management |