TY - JOUR T1 - Does juvenile Baltic sturgeon (<em>Acipenser oxyrinchus</em>) smell the enemy? JF - bioRxiv DO - 10.1101/476952 SP - 476952 AU - Maria Cámara Ruiz AU - Carlos Espírito Santo AU - Alfons Mai AU - Jorn Gessner AU - Sven Wuertz Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/11/30/476952.abstract N2 - Atlantic sturgeon (Acipenser oxyrinchus), also known as Baltic sturgeon, is considered extinct in German waters. Fish-rearing for conservation purposes still relies on classical hatchery technology producing fish not well suited for facing life in the wild, lacking behavioural skills such as foraging or anti-predation. Predation is hence a major source of mortality in newly stocked individuals. The aim of this study was to evaluate if naïve Baltic sturgeon juveniles were able to smell and recognize a common predator, sander (Sander lucioperca). Over a period of 30 days, three tanks from each group of Baltic sturgeon were attached to a rearing tank with sander (sander unit) and, as a control, carp (carp unit). Morphology of the dorsal scutes, distribution within the tank, stress (glucose, lactate and cortisol) and gene expression of brain plasticity and cognition were studied in comparison to the control group (carp unit). No significant differences were observed in any of the parameters measured. Thus, we conclude that naïve Baltic sturgeon is not able to innately recognize potential predators and future studies should focus on implementing predator odour together with chemical alarm substances. ER -