Body rather robust, spinose. Length of largest male 20 mm, female 16 mm.
Cephalon with an anterior projection, separated from pereionite 1 by a distinct suture.
Setal formula for terminal article of mandibular palp 1-10-1 to 1-12-1. Left mandible with 5-toothed incisor, 5-toothed lacinia mobilis, setal row of 3 serrate setae, molar with a plumose seta. Right mandible with 5-toothed incisor, lacinia mobilis serrate on the cutting margin, setal row of 2 serrate setae, molar with a plumose seta. Palp of maxilla 1 usually with five robust apical spines and several setae; outer lobe with seven apical spines, usually bifid but sometimes more branches with increase in size of individual. Inner and outer lobes of maxilla 2 quite setose on the apical margin and spines occasionally present. Outer lobe of maxilliped with 2 apical setae, one long apical spine, and up to 12 smaller marginal spines; inner lobe with two small spines and up to 12 apical setae, as many as nine of which plumose; palp similar to that of species of the genus Caprella .
Pereionite 1 with a dorsal anterior spine. Dorsal surface of pereionite 2 with a pair of spines at the mid-length of the pereionite and a single posterior spine, insertion of gnathopod 2 with a small spine, anterolateral margin produced into a triangular projection. Dorsal surface of pereionite 3 with a pair of anterior spines, sometimes reduced to small humps, a pair of mid-posterior spines, and a single posterior spine; anterolateral margin produced as in pereionite 2; lateral margin of pleura with anterior and posterior spines and a spine above the gills in males, females without a posterior spine. Pereionite 4 similar to pereionite 3 in males, female without a dorsal anterior spine. Dorsal surface of pereionite 5 similar to pereionite 3, pleura with only an anterior spine and a dorsally directed spine at the base of pereiopod 5. Pereionite 7 with a dorsally directed spine at the base of pereiopod 7.
Propodus of gnathopod 1 triangular with 2 proximal grasping spines, grasping margin not distinctly serrate; grasping margin of dactylus serrate, particularly at the tip. Propodus of gnathopod 2 quite robust, palm heavily setose with a small proximal tooth, anterior margin with a distal projection; dactylus not serrate.
Pereiopods 3 and 4 absent. Pereiopods 5-7, six-segmented, palm of propodus with a pair of proximal grasping spines.
Abdomen of male and female with 1 pair of appendages and a pair of setose lobes; in male appendage placed on a raised projection and uni-articulate; in female, appendage neither on projection nor articulated.
This species appears to be quite constant in body spination with the exception of the first pair of spines on the dorsal surface of pereionite 4. These may be present as fully developed spines or as only small humps.
This is an Arctic species, usually found in deeper water, down to 1026 metres. It is reported from the asteroid, Brisinga , but the species has also been collected from red and brown algae and hydroids.
Murman coast to Haugesund on the Norwegian coast, Spitsbergen, Faeroe Islands, Iceland, east and west coasts of Greenland.