Sars, 1905
Short Description:
Pseudochirella dubia is an aetideid calanoid copepod known after both sexes (female 4.80-6.10 mm and male 4.00 mm in length) from boreal, subantarctic and tropical-subtropical zones of the World Ocean, of mostly bathy-abyssopelagic.
Taxonomic Description:
Female. Total length 4.80-6.10 mm (length of specimens from the Kurile-Kamchatka Trench area: 5.8-6.10 mm). Cephalothorax 3.5-4.0 times longer than abdomen. Th5 posterior corners rounded, symmetrical. Genital segment symmetrical, its length and width are about the same. It is nearly as long as 2 following segments together. Ventral swelling strongly protruded, it is widest in its posterior part (lateral view). Abd1-3 are with hairs on the surface. Body surface of some specimens with "dotted structure". A1 longer than cephalothorax, may reach Abd 2-3, or the end of caudal rami. Ri1 A2 with 2 setae. Re1 A2 with 1 seta, in our specimens this seta is placed on the knob, small, but according to figures of A, Scott (1909), this seta is much longer, on Re2 A2 except distal seta there are 2 more setae: proximal and medial. Ri1 Md with 2, Ri2 Md with 9 terminal and 2 posterior setae. Mx1, Mx2 and Mxp typical of the genus. Re P1 3-segmented. Ri P2 unclearly 2-segmented (after Sars (1925) and A. Scott (1909): Ri clearly 2-segmented). P4 coxopodite with about 30 thin fan-like spines (Sars (1925) noted 14 spines).
Male. (Description after Sars (1925) with modifications). Total length 4.00 mm. Cephalon and Th1 unclearly separated. Th5 posterior corners rounded, without spines. Cephalothorax about 3 times longer than abdomen. Left Re2 P5 with 3 teeth in distal part of segment.
Vertical distribution:
Abysso-bathypelagic species, found in hauls in lower bathypelagic - abyssal (Grice and Hulsemann, 1967; Markhaseva, 1996), in the Kurile-Kamchatka region (Markhaseva, 1996). Species was recorded in total hauls from depths down to 7000 m.
Geographical distribution:
The species is registered to the North up to 62°N: the Davis Strait (Jespersen, 1934), to the South in the Atlantic Ocean to South Sandwich Islands; in the Pacific Ocean: to the Kurile Islands (Markhaseva, 1996). Was found to the South from 60°S in the Indo-oceanic and pacific sectors of the Southern Ocean (Markhaseva, 1996). Species is known from boreal, subantarctic and tropical-subtropical zones of the World Ocean (A. Scott (1909); Grice and Hulsemann (1967); Bjornberg (1973); Markhaseva (1996)).
Type locality: North Atlantic: 36°17'N 28°53'W (Sars, 1905).
Material examined:
36 females and 1(?) male from samples: 66, 68-70, 82, 83, 86, 97, 103, 121, 124, 126, 128, 139, 140, 163, 164, 181, 192, 200, 270, 339, 379. See examined samples module.