Claus, 1866
Short Description:
Euchirella rostrata is an aetideid calanoid copepod known after both sexes (female 2.95-3.95 mm and male 2.50-3.10 mm in length) from tropical, subtropical and temperate waters of the World Ocean, mainly epi-mesopelagic.
Taxonomic Description:
Female. Total length 2.95-3.95 mm. Cephalothorax about 4 times longer than abdomen. Crest absent. Rostrum comparatively long. Posterior Th5 corners rounded. Genital segment symmetrical. A1 nearly as long as body. Ri A2 slightly more than twice shorter than Re A2. Ri2 A2 with 8 setae on internal and 6 setae on external lobe, basipodite with 2 setae, Ri1 A2 with 1 seta. Md palp base and Ri1 Md without setae, Ri2 Md with 9 setae. Mx1 gnathobase with 4 setae on posterior surface, second and third internal lobes with 3 (2 long and 1 short) and 2 setae respectively; protopodite near the Ri base with 3 setae, Ri with 3 setae, Re with 10 (after Park (1978) with 10-11) setae, external lobe with 9 setae. First external spine on Re P1 long, covering two thirds of second spine's length. P4 coxopodite with 7-9 denticles (9 after Von Vaupel Klein (1984)).
Male. Total length 2.50-3.10 mm. Crest absent. Both spines on Re1 P1 well developed. P5 biramous, Ri well developed, right one of clavate shape. Re and Ri right not forming tongs.
Vertical distribution:
The species was found in hauls from epipelagial (Farran, 1929; Tanaka and Omori, 1969a; Bradford and Jillett, 1980), mesopelagic (Park, 1976b) and total hauls from 1300 m.
Geographical distribution:
The species is widespread in tropical, subtropical and temperate regions of the Pacific, Indian and Atlantic oceans (Vervoort, 1957). The species is known from the north-western and north-eastern, as well as south-western and south- eastern parts of the Pacific Ocean, antarctic and subantarctic waters of the Pacific and Indian oceans (Farran, 1929; Brodsky, 1950; Vervoort, 1957; Tanaka and Omori, 1969a; Bjornberg, 1973; Park, 1978; Bradford and Jillett, 1980; Von Vaupel Klein, 1984; Markhaseva, 1996)
Type locality: the western part of the Mediterranean Sea (Claus, 1866).
Material examined:
23 females and 4 males from samples 5, 6 and 573. See examined samples module.