Effects of replacing live food with formulated diets on growth and survival rates in Persian sturgeon (Acipenser persicus) larvae

This study was conducted to adapt Persian sturgeon larvae to commercially prepared diets over a period of 35 days. A total of 6000 Acipenser persicus larvae (mean weight: 0.406 +/- 0.047 g (Mean +/- SD; n = 180) were randomly stocked into 12 concrete tanks (diameter: 2.5 m, height: 30 cm). Each tank was stocked with 500 individuals. Three diets were used: (i) a formulated diets in the form of a paste; (ii) a formulated diet in pellet form, and (iii) a paste diet combined with chopped chironomid larvae. A control group fed live food (Daphnia + chironomid larvae + gammarids) was also used. Growth rates in the group 3 were significantly different (P < 0.05) from the other two groups. Highest body weight (2.51 g) was gained in experimental group 3 and the lowest weight (1.17 g) was observed in the second group. Highest survival rate (91.5%) was recorded in the control group while the lowest rate (7.2%) was observed in experimental group 2. This study revealed that by a gradual replacement of live food during a period of 35 days Persian sturgeon larvae can be successfully weaned to formulated diets.