effects of different photoperiods on the survival and growth of beluga sturgeon (huso huso) larvae

effect of different photoperiodic regimes was evaluated on growth performance and survival rate of the beluga ( huso huso ) prelarvae and larvae. newly hatched prelarvae were stored in 5 round fiberglass 500‑l tank with different photoperiod (24l:00d, 18l:06d, 12l:12d, 06l:18 d, 00l:24d) till 50 days post hatch with three replicates. light intensity was 200 lux during the experiment. feeding was started from 8 days post hatch using live artemia nauplii. higher total length, survival rates and lower body area, yolk area for beluga prelarvae obtained in long light photoperiods (24l:00d, 18l:06d). also, higher growth parameters of the beluga larvae observed in long light photoperiods while different photoperiods had no effect on survival rate. the present study indicated that growth performance and survival rates of larvae are significantly influenced by photoperiod. the photoperiod 18l:06d resulted in the best growth performance and survival rate during early development of the beluga.