A. Scott, 1909
Short Description:
Undeuchaeta intermedia is an aetideid calanoid copepod known after both sexes (female 3.56-4.50 mm and male 3.62-3.69 mm in length) from the Indian and the Pacific oceans.
Taxonomic Description:
Female. Total length 3.56-4.50 mm. Cephalothorax slightly less than 4 times longer than abdomen. Crest absent. Th5 posterior corners slightly asymmetrical, sometimes the right one is rounded (lateral and dorsal view). On the right side of genital segment there is a well visible dorsal spine; also there is one spine on the left and on the right from genital field (ventral view), and one of these spines well visible when looking laterally. A1 23-segmented, nearly as long as cephalothorax. Re1 A2 without setae. Mx1 protopodite with 4-5 setae near Ri base, Ri with 14 setae, in other features oral parts typical of the genus. P1-P4 typical of the genus.
Male. Total length 3.62-3.69 mm. Oral parts strongly reduced. Re1 P1 3-segmented. P5 right: Re1 with well visible spine on lateral side (in about first third of segment) and on the opposite side of segment on the same level there is small projection; internal part of segment is covered with wavy lines nearly parallel. Left Ri P5 reaching distal end of Re1. Re2 with spine-like projection on external distal border, internal proximal angle of Re3 prolonged into spine-like projection.
Vertical distribution:
The species was not found in surface layers (Vervoort, 1957), found in total hauls from 1500 m (Markhaseva, 1996).
Geographical distribution:
The western part of the Indian Ocean (Grice and Hulsemann, 1967; Markhaseva, 1996), the region of the Malay Archipelago (A. Scott, 1909), the equatorial, the north-eastern, the northern, the south-eastern parts of the Pacific Ocean (Esterly, 1911; Grice, 1962; Bjornberg, 1973).
Type locality: the Malay Archipelago (A. Scott, 1909).
Material examined:
3 females from samples: 400, 401, 403. See examined samples module.