(Montagu, 1808)
Description:
Carapace broader than long, dorsal surface smooth to unaided eye; margin of frontal region concave or with a shallow median incision. Antero-lateral margins of carapace almost straight, particularly posteriorly, forming a noticeable subacute angle with anterior portion of postero-lateral margin. Third maxilliped narrowing anteriorly. Chelipeds equal in size and stout, propodus swollen, margins of merus-dactylus slightly cristate; pereiopods usually smooth. Female broadly rounded bosses on epibranchial-mesobranchial regions usually strongly elevated; chelipeds shorter than in male; abdominal segments 4-6 fused. Male epibranchial-mesobranchial bosses not strongly elevated, sometimes capped with tubercles; chelipeds longer than in female; abdominal segments 3-5 fused; distal portion of first pleopod usually curved and stout.
Size:
Carapace length up to 10 (12) mm.
Habitat:
Depth range from 2 to 155 metres, on muddy sand and gravel. Ovigerous in January-August, larvae August-September.
Colour:
Very variable, carapace from reddish to greyish-white or yellowish-grey, sometimes spotted with red, sometimes with orange margin and pale pink median band. Some specimens variegated brown and black.
Distribution:
Shetland, Aberdeen, Northumberland, Yorkshire, Wash, Thames, Wight, Channel Isles, Plymouth, Scilly Isles, Bristol Channel, Isle of Man, Belfast, Clyde & Argyll, Minch, Mayo, Galway Bay, Fastnet.