“Rectarcturus tuberculatus sp. nov.
Diagnosis. Dorsum tuberculate; some tubercles extend beyond posterior margins on peraeonal segments, especially on I-III.
Description. Cephalic horns short, notched at apexes; folded anteriorly. Cephalon with several small tubercles; tubercles anterior to large tubercles on peraeonal segment I. Many tubercles on all peraeonal segments. Some, especially those on peraeonal segments I-III, extend beyond posterior border of peraeons. Edges of peraeonal segments each, except I, enlarged with laterally flat bosses that project beyond anterior border, especially on peraeonal segments II-IV. Pleon with anterior three segments strongly indicated; edges extended beyond edges of body proper (dorsal view); dorsum with low tubercles. Posterolateral spines moderately large with posterior margin strongly produced and with shallow notch.
Antenna 1 about 3 times length of basal peduncular segment; flagellum about as long as basal segment with about five groups of aesthetascs. Antenna 2 slightly less than half length of body; two flagellar articles.
Maxilliped normal with more or less curved sensory edge of endite; exopod with apex broadly rounded. Peraeopod I normal. Peraeopod II with proximal three segments short; carpus and propodus each slightly shorter than three proximal segments combined and each with many long setae. Dactylus narrow, elongate, and with few setae; unguis narrow, elongate, and slightly shorter than dactylus proper. Peraeopods III and IV longer than II, with spines on bases especially on IV. Valves smooth.
Measurements. Holotype gravid female 9.5 mm long.
Derivation of name. The name to the tubercles covering the dorsum.
Type locality. North of South Shetland Islands; Eltanin 6-363; 57°09'S, 58°58'W; 58°00'S, 58°50'W; December 7 and 8, 1962; about 3477-3590 m.
Distribution. Known only from type locality.
Affinities. The species is most like the type species in dorsal ornamentation, having many rounded tubercles instead of many elongate ridgelike tubercles. The edges of the peraeons are similar, and the configuration of the pleons is similar (especially lateral views).
Remarks. The depth at which this species was recorded (3477-3560 m) by far exceeds the greatest depth record (208 m) of the other three species in the genus. It also is the only one of the four from south of the Antarctic Convergence.”
(Schultz, George, 1981: 68-69)
