تاثير سطوح مختلف نمك در جيره غذايي بر شاخص هاي رشد و بقاء در فيل ماهيان جوان پرورشي Huso huso در آب شيرين

The effects of different dietary salt levels on growth and survival indices of beluga (Huso huso) juvenile cultured in freshwater

Present investigation was carried out to examine the effect of using different levels of salt in diets of great sturgeon (Huso huso) juvenile cultured in fresh water on growth and survival rate in Gorgan University Aquaculture Research Center. Seventy two great sturgeon juveniles were divided to four treatments and stocked in 12 circular tanks (250 L) after 10 days acclimation to control diet. They were fed on diets supplemented with 0, 0.5, 1 and 1.5% salt for 33 days. Growth, total length and survival indices were measured each two weeks. A completely randomized design was used for data analysis and Duncan multiple range test was used for means comparison. Based on current results, diet supplemented with 0.5% salt was better than the other treatments (P<0.05). The best body weight increase (99.16±6.3g), specific growth rate (3.26±0.16% day"1), feed conversion efficiency (0.87±0.04), food conversion rate (1.14±0.06), price index (8026.66±444 R) were observed in diet supplemented with 0.5% salt. There were no significant differences among treatments for survival rate (P>0.05). Based on the results of present study, investigation the effect of salt on digestibility and enzyme activity of fish digestive system is proposed in next researches.