EN
This paper presents selected data from the literature on the occurrence, chronology and ways of invasion, and some of the most important aspects of the biology of the Amur sleeper, Perccottus glenii. This Siberian freshwater fish species is a member of the family Odontobutidae, and it is an invasive alien species in Polish waters. The invasion of this fish in Poland was first noted over 16 years ago. The Amur sleeper is predatory, and it possesses an extraordinary ability to survive under even the most unfavorable environmental conditions. Thus, it is considered to be exceptionally dangerous to native ichthyofauna, and it is capable of annihilating populations of tiny fish.