Grice and Hulsemann, 1965
Short Description:
Chiridiella subaequalis is an aetideid calanoid copepod known after female (2.81-3.00 mm) from the north-eastern Atlantic, north-western Pacific and Indo-oceanic part of Antarctic from bathy- and abyssopelagic.
Taxonomic Description:
Female. Total length 2.81-3.00 mm. Cephalothorax about 4 times longer than abdomen. Anterior border of the skeleton structures of the genital field nearly smooth (ventral view). A1 23(?)-segmented, slightly shorter or as long as cephalothorax. Ri2 A2 with 6 setae on external lobe and 6-7 on internal; Re A2 and Ri A2 equal in length; basipodite without setae, coxopodite with 1 seta. Ri2 Md with 9 setae. Gnathobase of Mx1 with 9, second and third internal lobes with 1 seta and 4 setae respectively, Ri with 7, Re with 4, external lobe with 8-9 setae. Third-fifth endites of Mx2 each with 1 seta strongly thickened into spine, they are of nearly equal size. Mxp of studied specimen differed somewhat from that described by Grice and Hulsemann (1965): it has 3, not 2 medial setae on Ri1 Mxp and external surfaces of Ri3, Ri4 Mxp are covered with hair. P1 with one-segmented Ri and Re, our specimen with external proximal spine on Re not reaching the base of following terminal spine (according to Grice and Hulsemann the spine exceeds the base of following spine). P2 with one-segmented Ri, Re incompletely 3-segmented. Ri P2-P3 incompletely 3-segmented.
Male unknown.
Remarks. Regardless the small differences in setation of Mxp and the length of first external spine on Re P1 attribute the studied species to Ch. subaequalis.
Vertical distribution:
The species was found in hauls between 3000-4000 m (Grice and Hulsemann, 1965) and 1500-2000 m (Markhaseva, 1996).
Geographical distribution:
Atlantic Ocean: the north-eastern part (Grice and Hulsemann, 1965). Pacific Ocean: in the region of the Kurile-Kamchatka Trench. In the Indo-oceanic sector of Antarctic, to the South from 62°S (Markhaseva, 1996).
Type locality: 29°57'N 22°53'W (Grice and Hulsemann, 1965).
Material examined:
2 females from samples: 73, 379. See examined samples module.