Body without dorsal processes. Epimeral plate 3 posterior margin smooth, but angularly produced, distal angle with small tooth; in small specimens angular margin less distinct. Head with small rostrum, lateral lobes broad and rounded; eyes large, especially in male, kidney-shaped. Antenna 1 half body length, flagellum slender up to about 35-articulate. Antenna 2 little longer than 1, peduncle articles 4 and 5 about equal. flagellum long and slender, may be over 50-articulate. Gnathopods similar, moderately setose, propodus subrectangular densely setose, palm oblique delimited by 3 or 4 stout spines, palmar margin minutely spinulose. Pereiopods robust, spinose; pereiopods 5 to 7 basis with posterior margin weakly crenulate, dactylus robust. Uropod 3 rami strongly spinose, with few short setae, confronted margins minutely toothed. Telson triangular, apex rounded.
Up to about 8 mm.
Very variable; pinkish red; or pink with vivid red patches on body, coxal plates and proximal part of appendages; or pinkish purple with vivid white saddle on pereion; or yellowish white speckled or banded with red or brown.
Depth range from the intertidal to the shallow subtidal; locally very common amongst algae.
North East Atlantic, Arctic Ocean; European coasts from northern Norway to Portugal.