ABSTRACT
Spiny cheek crayfish (Orconectes limosus L.) were found in the Serbian part of the River Danube (August 2004, at 1112 km of the water course). A description of the biology, origin and distribution of this species, as well as the potential impact to the aquatic ecosystems is presented and discussed. This is the first record of this invasive crayfish in Serbian part of the River Danube. In addition, our results could indicate that there is potential risk for the expansion of O. limosus in other regional waters in the future.