Paraheterorhabdus compactus (Sars G. O. 1900)

The first basipodite of Mxp2 contains a straight median chaeta. Body massive. Abdomen is shorter than half the length of the cephalothorax, the larger chaeta of the left caudal branch is shorter than the abdomen.

North Atlantic, coasts of Ireland, Gulf of Gascony, Antarctic, Central Arctic Basin, West Greenland, North-western Pacific.

Oceanic bathypelagic species. In Antarctic waters found at depths greater than 500 m, in Greenland waters 1000-3000m, in the central Arctic – 200-2500m, in the North Pacific found in samples 4000-500m.

Female:
Cephalothorax is oval-shaped, with maximum width in the central part. Posterior corners of the last thoracic segment somewhat elongated and slightly turned to the sides. Abdomen is 2.5 times shorter than the cephalothorax. The genital segment is as long as the combined length of the next 2 segments plus a third of the length of the caudal rami. Length to width ratio in caudal rami is 3:1. The ventral projection on the genital segment very convex. A1 almost reach the end of the genital segment. The outer tooth on the Md is equal in size on the right and left side. The first two segments of the endopodite of P5 carry one chaeta each, the third – 6 chaetae. The larger chaeta on the second segment of the exopodite is massive, its length is twice as long as the width of the segment, it is very finely serrated at an angle. The distal segment of the exopodite of P1 with spines.

Male:
The second basipodite of the right P5 with a rounded pubescent projection, such a projection is absent on the left leg. The second exopodite of the right P5 carries a long narrow inner protrusion.

Female: 2,24-3,50 mm
Male: 1,98-3,60

Carnivorous species

密擬異肢水蚤（学名：Paraheterorhabdus compactus）为異肢水蚤科擬異肢水蚤屬下的一个种。