Feeding ecology of the American crab Rhithropanopeus harrisii (Crustacea, Decapoda) in the coastal waters of the Baltic Sea

The feeding ecology of the American crab Rhithropanopeus harrisii Gould, 1841 from brackish waters of the Baltic Sea was studied by analyses of the stomach repletion index (SRI) and stomach content with regard to sex, size and habitat (Dead Vistula River and the Gulf of Gdańsk). Neither the sex nor the size of an individual crab had a significant (P>0.05) influence on the SRI or on the diversity of food items found in the stomachs of R. harrisii. But the type of food consumed was significantly (P<0.05) dependent on the locality inhabited: the greater the biodiversity of the habitat, the richer the dietary composition. In Baltic coastal waters this species feeds on detritus, and also on animal and plant matter. Remains of Chlorophyta, Amphipoda, Ostracoda, Polychaeta, Gastropoda and Bivalvia were found in the stomachs of the specimens analysed.