effects of dietary lipid level on growth, feed utilization and survival of juvenile of beluga (huso huso linnaeus, 1758)

variation in growth, feed utilization and survival was assessed in sturgeon fingerlings of beluga fed different dietary lipid levels. all diets were iso-nitrogenous (protein = 45%) comprising 3.4-3.7 kcal digestible energy g-1. triplicate groups of 35 fingerling beluga with a mean initial wet weight of 2.14 ± 0.07 g (± sd) were fed with four experimental diets containing 6.7, 10.5, 14 and 17% crude fat for 48 days (water volume: 100 l.; water change rate: 1.4 l min-1). there were significant differences in final weight, body weight increase, specific growth rate, production index, hepatosomatic index, protein efficiency ratio, productive protein value and feed utilization ratio of fingerling beluga (p < 0.05). increasing lipid levels to 14% level improved the above indices. however, condition factor and survival were not affected by different dietary lipid levels (p > 0.05). the best growth rate, survival, feed utilization were obtained at 14% lipid level with de:cp ratio of 79.9 kcal g-1. these results indicate that optimal dietary lipid level for fingerling beluga is about 14% for these diets.