LAUSR

The tolerance of juvenile Amur sleeper Perccottus glenii and perch Perca fluviatilis to the effect of piscivorous predator pike Esox lucius has been studied in experimental conditions. In the majority of trials, Amur sleepers were consumed by pike much more efficiently. This trend remained in the aquaria of various volumes, with and without covers. As opposed to perch, juvenile sleeper do not rely on the behavioral responses of group defense, and this leads to its higher vulnerability to predation in the experimental conditions. The data of the present study confirm the results of field research on the key effect of piscivorous predators on the possibility for colonization of Amur sleeper in certain waterbodies.