Acipenser stellatus is found in the Black and Caspian seas and connecting rivers, to where it migrates for spawning in spring and summer. It is a critically endangered species [Z], driven to near extinction by overfishing, habitat destruction, and disruption of river connectivity. Although it has been in the focus of aquaculture because it is the source of the sevruga caviar, there is a severe lack of knowledge concerning biology and behaviour in the wild (home range, aggregation, aggression for example) and also many aspects of farming (aggression, environmental enrichment, stress, and slaughter). This lack of knowledge not only severely hinders the assessment of its welfare state but also impedes almost any perspective for improvement.