Markhaseva, 1996
Short Description:
Gaetanus rubellus is an aetideid calanoid copepod known after female (7.30 mm in length) from Izu-Bonin Trench.
Taxonomic Description:
Female. Total length 7.30 mm. Cephalothorax 4.5 times longer than abdomen. Frontal spine absent. Th5 posterior corners with moderate spines with thick bases, removed to the ventral side of posterior Th5 border (lateral view). A1 reaching the midlength of abdomen. Re1 A2 with 1, Re2 A2 with 3 setae. Md palp base with 2, Ri2 Md with 9 terminal long and 1 posterior short setae. Second Mx1 internal lobe with 5, Ri with 11 setae. Lateral plate on Mxp protopodite present. P1 with 3-segmented Re, supplied with external spine on each segment. First and second external spines not reaching the distal border of Re2 and Re3 P1. P4 coxopodite with about 35 thin spines.
Male unknown.
Remarks. The species is very similar to G. inermis Sars, 1905, differs in the presence of spines on Th5 posterior corners and by longer external spines on Re1 and Re2 P1.
Vertical distribution:
The species is known from total haul 0-8370 m.
Geographical distribution:
The species is known from the Izu Bonin Trench region only.
Type locality: 29°17'N 142°47'E.
Material examined :
1 female from sample 202. See examined samples module.
Holotype: 1 female, N 1/66262, Izu Bonin Trench region, 29°17'N 142°47'E, R/V "Vitjaz", 57th voyage, 10.05.1975, sta. 7406, stratum 0-8370 m, ring-trawl.