(Milne-Edwards, 1830)
Description:
Pereion and pleon segments without posterodorsal teeth, pleon weakly keeled dorsally with a small notch marking the posterior end of the keel. Head with a short curved rostrum, lateral lobes weakly sinuous; eyes large, especially in male, kidney-shaped. Coxal plates 1 to 4 small in male, much longer and broader in female, distal margins weakly setose, also with small setules on the surface of the plates. Epimeral plates 1 to 3 distal angle with a small tooth, posterior margin convex. Female antenna 1 about one-third of the body length, peduncle articles 1 and 2 about equal in length, article 3 very small, flagellum up to about 25-articulate. Female antenna 2 little longer than antenna 1, peduncle article 5 much longer than article 4, flagellum up to about 25-articulate. Male antenna 1 peduncle article 2 longer than article 1, tapering distally, flagellum very slender and much longer than in female. Male antenna 2 peduncle more robust than female, article 4 tapering distally; confronted margins of peduncle articles in male with many tufts of short fine setules. Gnathopod 1 basis robust and densely setose, propodus much longer than the carpus, oval, palm oblique, almost straight, delimited by a pair of slender spines, palmar margin with several small spinules; merus, carpus and propodus strongly setose, setae stout, some setae pectinate. Gnathopod 2 basis robust, less densely setose, propodus a little longer than the carpus, subrectangular, palm strongly oblique, almost straight, delimited by a pair of slender spines; merus, carpus and propodus with stout setae, some setae pectinate, but less dense than in gnathopod 1. Pereiopods 3 and 4 dactylus small; in female basis densely setose, other articles spinose but almost devoid of setae; in male, basis, merus, carpus and propodus with long marginal plumose setae. Pereiopods 5 and 6 basis expanded, distal margin prolonged, angular; pereiopod 7 basis with the posterior margin coarsely dentate, distal angle rounded. Coxal gills deeply pleated. Uropod 3 rami three times the length of the peduncle; in male the margins with small spines and many long plumose setae; in female spines larger but with a few short plumose setae. Telson a little longer than wide, truncated distally, cleft to three-quarters of the length, lobes slightly overlapping medially, each with one or two apical spines.
Size:
Up to about 10 mm.
Colour:
Whitish, with brown patches on the dorsal surface and the coxal plates.
Habitat:
Depth range from the lower intertidal to about 50 metres. Locally common.
Distribution:
North Atlantic; American and European coasts; Arctic Ocean. European coasts from northern Norway to the western Mediterranean; North Africa to Senegal.