Aetideus divergens is an aetideid calanoid copepod known after both sexes (female 1.69-1.90 mm and male 1.25-1.43 mm in length). Species found mostly in the epipelagic of the Pacific Ocean.
Female. Total length 1.69-1.90 mm. Rostrum with button in the middle of excavation between rami, which as against of A. armatus with narrow bases. Width depth ratio of excavation close to that of A. pseudarmatus 0.85-1.2 (Markhaseva (1996) and calanoids from Japanese waters (Tanaka, 1957a). Posterior Th5 points exceeding posterior border of genital segment, slightly divergent (in dorsal view). Spermatheca with moderately long, thick duct between ventral and dorsal parts. A1 about the same length as body or reaching the middle of abdomen. Oral appendages in principle identical with that of A. armatus , Ri2 Md with 10 setae (9 terminal and 1 dorsal). Basipodite of right P1 with external tooth-like projection. There are no teeth near the base of internal seta at P4 coxopodite.
Male. Total length 1.25-1.43 mm. Points of Th5 posterior corners exceeding Abd1. Caudal rami are 2.35-2.55 times longer than wide. Re3 P2-P4 terminal spines with 24, 22 and 19 denticles respectively.
The species was found from 150-300 m and from depths 150, 550 and 1000 m (Tanaka, 1957a; Bradford, 1971a).
The north-eastern part of the Pacific Ocean (Bradford, 1971a), the north-western part of the Pacific Ocean (Tanaka, 1957a), the region of the Izu-Bonin Trench (Markhaseva, 1996).
Type locality: off British Columbia: 52°02'N 132°53' W (Bradford, 1971a).
1 female from sample 202. See examined samples module.