Mostly clear; edges of the segments, as well as ovaries and egg-ducts in females dark blue to black. The back side of the genital segment and first abdominal segment brown, anal segment blue. Eye dark, reddish-brown. Exopodites of P1 and P2 tinted with black. The bases of feeding appendages in males are blue. Reddish-brown pigment may be present on the edges of the segments. The geniculate segments in male A1 bright brick red.
Internal projection on P5 with 10-16 teeth on both sides. Projection curved to be nearly parallel to the long axis of the segment.
South-west Sea of Japan, Bering Sea, Sea of Okhotsk, Bay of Sakhalin, Arctic coast of Alaska. Atlantic coast of North America north of Woods Hole.
Coastal, brackish
Female:
Head separate from thorax, 4th and 5th segments separate, the back corners of the last thoracic segment carry large wing-like growths, which are very wide and have sharp tips, extend beyond the end of the genital segment. Rostrum bifurcate with 2 small filaments. Abdomen contains 3 segments. Genital segment swollen at the distal end. P5 structure significantly differs from other species in the genus. The second segment carries no armature and is as long as wide. The internal projection of the third segment is long (extends somewhat beyond the spines on the distal segment), carries 10-16 teeth on both edges and faces forward, rather than inward. The outward edge of the third segment carries 2 spines - an apical spine and a shorter outer spine. Caudal rami shorter than in Eurytemora pacifica, are much longer than the anal segment. Inner margins of caudal rami carry long, fine hairs.
Male:
The back corners of the last thoracic segment are rounded, body more slender than in females. A1 geniculate. Abdomen contains 5 segments of similar length, with the exception of the last segment, which widens distally and ends in 2 rounded swellings. Right P5 5-segmented, the third segment is longer and thinner than the second one; the distal segment is almost hair-thin and only slightly longer than the previous segment. The third segment of both P5 armed with 3 spines.
Egg-brooding species
Female: 0,73-1,60 mm
Male: 0,87-1,75 mm
Selective filter-feeders; phytoplankton and detritus