First attempt of rearing the Siberian sturgeon (Acipenser baerii Brandt, 1869) in black sea water.
The most suitable sturgeon species for culture in artificial systems are freshwater and non-migratory species: sterlet - Acipenser ruthenus - and Siberian sturgeon - Acipenser baerii, recently introduced in Romania. The experiment aimed at establishing the age and salinity thresholds to be taken into account in attempting to rear (Siberian sturgeon - Acipenser baerii) in a recirculating system using Black Sea water. From the point of view of adaptability in general, in about a week the individuals adapted to the captive breeding conditions of NIMRD's recirculating system. The specimens also easily adapted to manipulation during measurements, showing calm handling behavior. The food used was very easily accepted, the active feeding behavior being observed even in the presence of the staff. Throughout the experiment, the fish were active. The survival rate was 100%. However, adaptability to the brackish environment has posed problems. The experimental batch became more sedentary and ingested significantly less food compared to the control group, when salinity exceeded 3 per mil. Upon reaching the 7 per mil threshold, all individuals were already completely refusing food, which is why it was decided to stop sea water input. The return to freshwater caused the resumption of feeding behavior in just a week, calling for further research on the osmoregulatory mechanisms of A. baerii.