Giesbrecht, 1888
Short Description:
Euchirella bella is an aetideid calanoid copepod known after both sexes (female 3.70-4.18 mm and male 3.26-3.70 in length) from the Pacific and Indian Oceans, mainly in epipelagic waters.
Taxonomic Description:
Female. Total length 3.70-4.18 mm. Cephalothorax nearly 3.5-4.4 times longer than abdomen. Crest absent. Rostrum well visible, robust. Th5 posterior corners rounded (dorsal and lateral view). Genital segment slightly asymmetrical with smooth projection on the right (dorsal and lateral view). A1 reaching nearly the midlength of abdomen, or exceeding caudal rami. Ri A2 4-5 times shorter than Re; coxo- basipodite and Ri1 A2 with 1 seta each, Ri2 A2 lobes with 5 setae each. Md palp base and Ri1 Md without setae, Ri2 Md with 9 setae. Mx1 gnathobase with 2 setae on posterior surface, second and third lobes with 3 and 1 seta respectively, on protopodite near the Ri base 2 setae (1 long, robust and 1 small); Ri with 4 setae; Re with 10 and external lobe with 7 setae. Mx2 and Mxp typical of the genus. P1 with 1 external spine slightly exceeding the base of second spine. P2-P4 typical of the genus, terminal Re spines with 20-21 denticles. P4 coxopodite with 3-4 robust, thick spines (or 5 after Grice, 1962; Tanaka and Omori, 1969a; Von Vaupel Klein, 1984), coming from general base.
Male. (Description after Tanaka and Omori (1969a) with modifications). Total length 3.26-3.70. Crest present, very low. A2 with 6 setae on each Ri2 lobe. P5 biramous, left Ri P5 rudimentary, not reaching proximal border of right protopodite. Right Ri P5 with 4 (in original specimen with 3) projections, Re also with 4 projections.
Vertical distribution:
The species is known from epipelagial (Sewell, 1947; Grice, 1962; Von Vaupel Klein, 1984), in total hauls from mesopelagic and depths from 8000 m (Markhaseva, 1996).
Geographical distribution:
In the Indian Ocean to the South to 5°S (Von Vaupel Klein, 1984), in the Pacific Ocean: from the region of Peru and to 20°S (Tanaka and Omori, 1969a), from the equatorial part of Ocean (Grice, 1962; Von Vaupel Klein, 1972; 1984), from the region of Marianas Trench (Markhaseva, 1996), from the north-western part of the Izu region (Tanaka, 1957b).
Type locality: 15°N 138°W (Giesbrecht, 1888).
Material examined:
1 female from sample 201. See examined samples module.