Fine tuning of feeding practices for hatchery produced Persian sturgeon, Acipenser persicus and Beluga sturgeon, Huso huso

In this work, we investigated the effects of various feeding treatments on the survival and growth of Huso huso and Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate) of first-feeding larvae were fed according to four main feeding regimes: (1) live food (live nauplii of brine shrimp Artemia urmiana); (2) indirect transition (57days live food followed by gradual transition to formulated diet); (3) direct transition (using different combinations of live and formulated diet from the start feeding onwards); and (4) formulated feed (FD) from the start of feeding. In H. huso larvae, combining live food and manufactured diets (co-feeding) from the first feeding stage onwards (direct transition) resulted in significantly higher weight gain than the other regimes. Survival was significantly higher in H. huso larvae fed solely live food or the direct transition regimes compared with indirect transition and FD. In A. persicus larvae, growth and survival were higher in the indirect transition feeding regime than in the other regimes. On the basis of the results of this study, we recommend co-feeding of H. huso immediately from the commencement of exogenous feeding, but co-feeding of A. persicus should start 7days after prior feeding with live food.