Females: Genital segment with 2 lobes on each side and lobes less than 1/2 as long as the width of the segment. Internal projection on P5 wedge-shaped or triangular, with straight sides. Caudal rami over 5 times as long as wide.
Alaska (coastal and lagoons)
Freshwater/brackish
Females: Head separate from thorax, 4th and 5th segments separate, the back corners of the last thoracic segment in females carry large wing-like growths, and are rounded in males. Rostrum bifurcate with 2 small filaments. Abdomen contains 3 segments. Internal projection of P5 exopodite with fewer than 8 teeth along the distal margin; hair-like microsetules may be present on one or both sides of the projection margin. Genital segment lobes less than half as long as the width of the segment, caudal rami 4.8-6.6 times longer than wide. Projection on the first segment of the P5 exopodite wedge-shaped or triangular, with straight sides, and the tip of the projection reaches the tip of the second segment. Lack microspine patches and on the 3rd segment of the abdomen.
Egg-brooding species
Females: 1.12-1.25 mm
Males: 1.00-1.20 mm
