Effects of different three live foods on growth performance and survival rates in Beluga (Huso huso) larvae

To determine the best live food and to reevaluate the optimal weaning period for beluga fish (Huso huso) larvae, seven experimental diets: Daphina (DP), Chironomids (CH), Gammarid (G), Daphina + formulated diet (DPFD), Chironomids + formulated diet (CHFD), Gammarid + formulated diet (GFD) and formulated diet (FD) in triplicate groups were fed to 4662 sixteen-days-old larvae which were captured from the stock tank and randomly distributed into 21 tanks. The microdiets contained 48-50% crude protein, 12-13% crude fat, 9-11% moisture and 8.5-9.5% ash. After 25 days feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed CHFD were significantly higher than those of fish fed the other diets (P<0.05). Frequent cannibalism and higher mortality in larvae fed G, GFD and FD diets were observed. These results may show the importance of live food followed by formulated diets in a gradual application pattern, as early as on the fourth to fifth day after hatching.