A new record of the invasive blue crab (Callinectes sapidus Rathbun, 1896) and his parasite from the Baltic basin

Abstract

Summary: A specimen of the invasive Callinectes sapidus was recently found in the catchment basin of the Baltic Sea (Lake Dąbie, Poland). The discovery is significant because it indicates a widening of the crab's biogeographic range in northern Europe and confirms its expansion along European estuaries. The captured juvenile specimen from Lake Dąbie (estuary of the Oder River) had a carapace width (CW) of 125.58 mm, carapace length (CL) of 53.23 mm, and weight (w) of 100.19 g. This is the first record of this species in this part of the Baltic Sea catchment basin, following the discovery of a female caught in a plaice net northeast of Copenhagen (1951) and an adult male caught off Skagen, Northern Jutland, between the Kattegat and the Skagerrak (2007). Keywords: Blue crab, Callinectes sapidus, Alien species, Spread, Poland, Parasite, Trichodina sp.