Colossendeis microsetosa Hilton 1943

Colossendeis microsetosa Hilton

Colossendeis microsetosa Hilton, 1943a:4.

Colossendeis orientalis Losina-Losinsky, 1958:29, 31, 34 [key], fig. 4.

MATERIAL EXAMINED.—Aleutian Islands, Unalaska Island, off Dutch Harbor, 54°01′40″N, 166°48′50″W, 640 m, R/V Albatross, sta 3331, 21 Aug 1890 (1, holotype, USNM 81528).

Another specimen, not a type, from the same station, which was identified as Colossendeis sp. by L. Giltay and apparently not seen by Hilton.

Aleutians, off Kiska Island, 51°32.6′N, 177°19.3′E, 377 m, R/V Miller Freeman, cruise 833, sta 4, 28 Jul 1983 (1 spec.). Aleutians, off Little Tanaga Islands, 52°02.1′N, 176°22.6′W, 249 m, R/V Miller Freeman, cruise 833, sta 56, 6 Aug 1983 (1 spec.).

DISTRIBUTION.—The type locality is to the east of the western Aleutian Islands localities of the Miller Freeman. Its depth range is from 249 to 640 m.

The western Aleutian localities of this species are very shallow in relation to the majority of depths recorded for members of this deep-sea genus, but this same phenomenon occurs in Antarctic seas where some Colossendeis have been taken in 20 to 30 m or even less. Colossendeis microsetosa is only known from the Aleutian Islands except for Losina-Losinsky's specimens, which came from the Sea of Okhotsk.

DIAGNOSIS.—Proboscis moderately narrow, expanding proximally to midpoint, with slight taper distal to midpoint, about 1.8 times length of trunk, with moderate distal downcurve in lateral view. Trunk typical, lateral processes slightly longer than their diameters. Ocular tubercle a truncate cone, anterior pair of eyes twice larger than posterior pair. Abdomen carried horizontally, moderately long, extending beyond distal rim of first coxae of 4th leg pair.

Palp segment 3 about 1.3 times length of segment 5, distal 5 segments subequal in length, with ventral fields of tiny spines. Legs slender, tarsus short, only about 0.4 times as long as slightly curved propodus. Both tarsus and propodus with very short sole spines and scattered lateral and dorsal setae. Terminal claw about 0.3 times length of propodus.

slope