Corners of the last thoracic segment with a strong spine. Terminal segment of P5 in females forms a strong spine twice as long as the second segment and is coarsely serrated on both sides. The second segment of P5 is longer than wide and bears a seta three times as long as the terminal spiny segment.
Cosmopolitan: tropical and temperate (limited by latitudes 40° N & S, except in the extreme north Pacific (Canada Basin) cited by Wilson, 1950)
Oceanic and littoral, epipelagic.
Females:
Posterior corners of the last thoracic segment with a large point, reaches to 1/3 of the genital segment. Terminal segment of P5 spine-like with coarse spinules; 4 posterodorsal spines are present on the genital segment and 2 on the postgenital segment. A1 1st segment with coarse anterodistal spine.
Males:
Posterior border of the abdominal segments almost naked; spines on posterior corner of the cephalothorax do not extend to the posterior border of the 1st abdominal segment. The left exopodal segment 2+3 on P5 with 3 terminal spines and a pair of subterminal spines, one of which is plumose.
Female: 0,90-1,30 mm
Male: 0,70-0,90 mm
