Epibiota associated with setae on Chinese mitten crab claws (Eriocheir sinensis H. Milne-Edwards, 1853): a first record

Eriocheir sinensis H. Milne-Edwards, 1853 is a non-native species found in European waters. Analyses of mitten crabs caught in brackish waters (Gulf of Gdańsk, Poland) and in freshwater (Havel River, Germany) have indicated that numerous epibionts (possibly temporary) inhabit the dense setal mats that cover the chelipeds. Of the 950 associates found on 22 crabs collected from brackish water, the most abundant were Nematoda (82.3%), followed by Bivalvia (10.3%), Crustacea (5.6%), Oligochaeta (1.2%) and Gastropoda (0.6%). In comparison, 1280 specimens (Chironomidae – 67.6% and Halacaridae – 32.4%), were identified from 13 crabs collected in freshwater. As this crab can migrate long distances, it is capable of transporting native and non-native species via its mittened claws to new habitats.