Effect of Temperature on Growth and Survival of Huso huso Larvae from Hatching Stage to Yolk Sac Absorption

In the present study, the effect of temperature on growth and survival of Huso huso larvae in the stage of larvae to yolk sac absorption was investigated. In this experiment 450 freshly hatched larvae of great sturgeon with initial weight of 20±0.97 mg were used in five thermal treatments at 10, 15, 18, 21 and 24 °C and three replicates for each in 10 days, raised in 20 l plastic container with the inflow rate of 2 l/min. The results of this study showed that the higher temperature of the water caused the more infant mortality and less survival. The temperature of 10°C created by a cooling machine for larvae exposed to this thermal group was fatal in their first minutes of arrival and their mortality rate reached to 100%. Among other thermal groups, the highest mortalities occurred at 24°C, (7.33±1.15) and the lowest losses happened at 15°C (1.00±0.32). As water temperature rises to 24°C, the time of absorption of yolk sac in great sturgeon larvae obviously decreases. The minimum growth rate of larvae was seen in 21°C. Therefore, lower mortality and higher weight gain of larvae (84.00 ±0.8 mg) at 18°C could be considered the appropriate temperature for culture in this period.