(Linnaeus, 1761)
Description:
Carapace convex longitudinally, dorsal surface smooth with numerous club-shaped setae, sub-median lobes very broad, margins sometimes minutely serrate or tuberculate. Second and third peduncular segments of antenna not touching margin of front. Antero-lateral margins of carapace with five spinose teeth, first and second smaller than rest. Chelipeds stout, carpus tuberculate or spinose, larger cheliped with propodal surface tuberculate, smaller with spiniform tubercles; second and fifth pereiopods moderately stout and setose, usually with numerous club-shaped setae, upper margin of carpus often with a distal spine. Female chelipeds less robust and less spinose than in male.
Size:
Carapace length up to 9 (15) mm.
Habitat:
Depth range from low water mark to 75 metres. Ovigerous April-August, larvae May-September.
Colour:
Carapace reddish brown, sometimes purple, chelipeds brownish to purple, inner surfaces orange to cream; pereiopods with alternating bands of purple and white or grey.
Distribution:
Yorkshire, Wash, Thames, East Channel, Wight, Portland, Channel Isles, Plymouth, Scilly Isles, Bristol Channel, Cardigan Bay, Anglesey, Liverpool Bay, Solway, Isle of Man, Dublin, Belfast, Clyde & Argyll, Minch, Galway Bay, Fastnet, Cork.