A Blue swimming crab (Portunus pelagicus) is a hairy crab refers to a square shaped carapace, a little longer than wide, markedly convex and uneven, bearing four sharply edged epigastric lobes.
Propodus of the fifth pereiopod rather narrow and slender with dactylus claw-shaped. Males produce an intensive mitten-like covering on the claws, with hairs both at inner and outer surfaces or only at the outer surface (always naked and smooth in other Eriocheir species). No longitudinal row of hairs on dorsal part of propodus in the anterior two pairs of ambulatory legs. Front with four acuminated and deeply separated teeth. Four anterolateral tooth distinct (not rudimentary). Its area of origin is in temperate and tropical waters between East Russia (Vladivostock) to South-China, including Japan and Taiwan, with its centre of occurence in the Yellow Sea. Introduced into European waters in the early begining of 1900 century (first recorded from the German river Aller in 1912). More recently found in North-America (e.g. Detroit River, Great Lakes, San Francisco Bay in 1992) and Hawaii (1950s). Among possible vectors for these introductions are cited the ballast water of ships.
German : chinesische Wollhandkrabbe .
Japan : Chugoku-mokuzugani .
Spain : cangrejo peludo chino .
UK : hairy crab .