Leach, 1820
Description
Adult carapace nearly circular, flat, a little wider than long, postero-lateral margin a little contracted, dorsal surface smooth, with indistinct regions.
Five antero-lateral teeth small, somewhat projecting forward. Front of carapace with three shallow teeth (between the inner orbital teeth).
Chelipeds (P1) equal, little longer than width of carapace, slightly sexually dimorphic. Pereiopods 2-4 compressed and little shorter than P1. Fifth pereiopod (P5) shorter than the other pereiopods, last two segments (propodus and dactylus) broad and flat; dactylus oval. All pereiopods with moderately haired margins.
Ovigerous females in spring. Megalopa and juvenile stages: P.henslowii
Ecology
Pelagic species; the conspicuous pelagic swarming of predominantly males, is most probably related to the reproduction cycle.
Size
Carapace length 40 mm, width 48 mm.
Colour
Reddish brown, underside pale.
Distribution in the North Sea
Adults rare in the North Sea; recorded east from Shetland and in the Skagerrak (see Christiansen, 1969).
World distribution
E Atlantic, from British Isles to Morocco, W Mediterranean. (Very common off the Spanish and Portuguese coasts).