Leitoscoloplos abranchiatus ( Hartman, 1967 )

Blake, James A., 2017, Polychaeta Orbiniidae from Antarctica, the Southern Ocean, the Abyssal Pacific Ocean, and off South America, Zootaxa 4218 (1), pp. 1-145 : 18-19

Leitoscoloplos abranchiatus ( Hartman, 1967)

Figure 6 A–C

Haploscoloplos abranchiatus Hartman, 1967: 103 –104; Rozbaczylo 1985: 129. Haploscoloplos sp. Hartman 1978: 156 (in part, Sta. 69-21).

Leitoscoloplos abranchiatus: Mackie 1987: 720 .

Material examined: Scotia Sea, West Scotia Basin , Falkland Islands, Eltanin Sta. 6-350, 2452m, Menzies trawl (3, USNM 56455 ) . —off Cape Horn, Eltanin Sta. 4-112, 20 Jul 1962, 55.52°S, 61.92°W, 4008 m, holotype and 7 paratypes, ( USNM 55531–2 ) . —off Tierra del Fuego, R/V Vema Sta. V- 17-56, 4006 m, (1, LACM-AHF Poly 5010) — South Shetland Islands, Eltanin Sta. 4-138, 1437 m (3, USNM 56454 ) .—off South Georgia, Eltanin Sta. 9- 711, 2983– 3331 m (1, USNM 60630).—Drake Passage, Eltanin Sta. 9-740, 384– 494 m (1, USNM 61944 ).— South Orkney Islands, Eltanin Sta. 6-1082, 298 – 302 m (1, USNM 60631 ).— Weddell Sea, Antarctica , Glacier Sta. 69 - 21, 2288 m (1, USNM 61945). — Weddell Sea , ANDEEP III ANT XXII- 3 , R/ V Polarstern, Sta. PS-67/078 - 6, 2168 m (1, SEM, JAB); Weddell Sea, abyssal plain, ANDEEP SYSTCO ANT XXIV-2, R/V Polarstern, Sta. 33- 14, 5338 m, 6 specimens ( ZMH P-27794).— South Pacific Ocean , Albatross Cordillera, Eltanin Sta. 14-1250, 3638 – 3825 m (2, USNM 60632).

Description. A small species, up to 18 mm long, 1.0 mm wide for about 30 setigerous segments. Prostomium conical, narrowly rounded on anterior margin ( Fig. 6 A); peristomium deeply folded, with 2–3 superficial annuli. Thoracic region with 9–13 setigers. Thoracic parapodia with short, conical noto- and neuropodial postsetal lobes. Abdominal parapodia only weakly elevated dorsally; with short, fingerlike notopodial postsetal lobes; neuropodia flattened, prolonged, rectangular in shape, distally entire ( Fig. 6 B). Thoracic parapodia with fascicles of long crenulated capillaries; abdominal notopodia with capillaries and 1–2 furcate setae, each with unequal tynes connected by row of thin needles ( Fig. 6 C). Branchiae entirely absent. Pygidium unknown.

Remarks. This species was well described by Hartman (1967) and is illustrated here for the first time. Leitoscoloplos abranchiatus is readily differentiated from related forms by the numerous long, silky appearing capillaries of the thoracic region, the complete absence of branchiae, and abdominal parapodia that are lateral or only weakly elevated.

Distribution. Subantarctic and Antarctic seas, 1400–5338 m.

Figures

FIGURE 6. Leitoscoloplos abranchiatus (Hartman, 1967). Holotype (USNM 55531). A, anterior end, dorsal view; B, abdominal parapodium, anterior view; C, furcate seta. — Leitoscoloplos simplex n. sp. Holotype (USNM 1407119). D, anterior end, dorsal view; E, anterior abdominal parapodium, posterior view.