The crayfish Orconectes limosus was first found in the Grodno province of Belarus in June, 1997. It has immigrated from Poland and at present has become established in the rivers Shlyamitsa, Marykha, and Chernaya Gancha, and the Avgustovsky Channel. It is thought to have been in this region for about 6–10 years. Along these rivers, Orconectes limosus has penetrated into the Neman River draining to the Baltic Sea. A stable population of the intruder is known in the Shlyamitsa. The single trap catch per day amounted to 22 individuals. Mean sizes were 7.49 ± 0.76 cm for females and 7.42 ± 0.74 cm for males. Orconectes limosus has been found in the diet of the perch (Perca fluviatilis),burbot (Lota lota),and mink (Mustela vison).