Forsman, 1949
Description:
Body narrowly oval in females; males smaller than females and broadest across the posterior pereion segments. Lateral margins of both sexes fairly sparsely fringed with spines. Antenna 1 very small with a reduced flagellum; antenna 2 well developed but shorter than the body. Eyes large and situated laterally, particularly in males. Mandible with a strong, truncated molar process. Coxal plates of pereion segments not visible from above. Pereiopods of male 1 to 4 with many curved setae on the propodus, carpus and merus, pereiopod 7 but not 6 with a large spine on the carpus. Pleon of one small, inconspicuous segment, others all fused with the telson to form a large, shield-shaped pleotelson. Pleotelson posterior border fairly deeply excavate where uropods are inserted. Uropods terminal, small, much shorter than the pleotelson and barely projecting beyond the pleotelson notch in which they are set. In females the first pair of pleopods absent, second forming a plate-like operculum covering the remaining pleopods. Preoperculum of male T-shaped with only slight lateral extensions to each arm of the T.
Males up to 3.0 mm body length; females up to 4.5 mm. Colour grey patterned with black in various colour varieties.
Habitat:
This species is most common at HWN and below, mainly among algae such as Fucus serratus .
Distribution:
It ranges from sheltered marine shores to estuaries, but is patchy in its distribution in the low salinity waters off Finland. Occurs in Europe from France to Norway, including the Baltic, Greenland and the Atlantic coast of North America.