Effect of Animal Origin Feeds and Frequency of Feeding on Growth, Survival and Cannibalism in Wallago attu (Bloch Schneider) Larvae During Hatchery Rearing

The growth, survival and cannibalism of Wallago attu larvae were assessed using different animal origin feeds and frequency of feeding during hatchery rearing. The weight (189±11.85 mg) attained by the larvae fed on goat liver, was significantly higher (P 0.05) than those fed on plankton (120±4.36 mg), fish (125±6.66 mg) and molluscs (139±4.06 mg). The specific growth rate, percent weight gain and final weight were similar for the other feeds. The final length, weight and specific growth rate were highest in larvae fed once per day followed by larvae fed 2-times, 3-times and 4- times per day, but overall biomass production was greatest at 3 or 4 feeds per day compared to feeding once a day. The percent survival increased significantly (P 0.05) with increase of feeding frequency. More than 50% survival was observed in larvae fed 3-4 times a day with goat liver compared to 27% in larvae fed once a day. An inverse relation was also observed between feeding frequency and percent cannibalism. Therefore, goat liver is considered to be the best feed and resulted in lower cannibalism and increased survival during indoor rearing of W. attu larvae when fed 3-4 times aday.