Lycenchelys antarctica Regan 1913

Lycenchelys antarctica Regan, 1913

Lycenchelys antarcticus Regan, 1913: 242, pl. IX, fig. 3 (type locality: abyss off South Orkney Islands); Norman, 1938: 81, fig. 52.

Lycenchelys atacamensis Andriashev, 1980: 1105, figs. 1-4 (type locality: Peru-Chile Trench).

Lycenchelys antarctica: Anderson, 1988: 88, fig. 28; Anderson, 1990b: 258, fig. 2.

Material examined. Scotia Sea: USNM 356654 (1 specimen; 181 mm SL), W of South Orkney Islands, 60°45.5'S, 48°13.5'W, 2511-2542 m, ISLAS ORCADAS coll. UMO 116, 10 ft beam trawl, 18 Feb. 1976, H. H. DeWitt. SAM 34530 (1; 242 mm SL), N of Elephant Island, 60°37.2'S, 54°55.9'W, 3213-3219 m, POLARSTERN sta. AGT-39, Agassiz dredge, 26 Nov. 1996, K.-H. Kock. SAM 34600 (1; 211 mm SL), N of Elephant Island, 59°09.5'S, 58°32.3'W, 3721-3723 m, POLARSTERN sta. AGT-2, Agassiz dredge, 15 Nov. 1996, K.-H. Kock. Weddell Sea: MNHN 1990-645 (2; 135-154 mm SL), off Kapp Norvegia, 71°09.0'S, 13°48.0'W, 2025-2037 m, POLARSTERN sta. 295, Agassiz beam trawl, 21 Feb. 1989, W. Arntz.

Diagnosis. Lycenchelys antarctica is distinguished from its congeners by the following combination of characters: single, ventrolateral lateral line; preoperculomandibular pores usually nine; vertebrae 117-138; predorsal length 27-33 % SL; free dorsal-fin pterygiophores 6-16.

Description. Vertebrae 26-27 + 91-97 = 117-124; D 102-108; A 95-100; P 15-16; C 8-10; pelvics 2; branchiostegal rays 6; gill rakers 2 + 12; vomerine teeth 4; palatine teeth 4-6; pseudobranch and pyloric caeca absent. Following proportions as percent SL: head length 15.3-15.9; head width 5.6-7.9; head depth 6.2-7.2; predorsal length 28.7-29; preanal length 35.4-36.7; pectoral base depth 4.3-4.4; pectoral-fin length 7.9-9.7; body height 5.3-7.4; gill slit length 5.0-5.6. Following proportions as percent HL: head width 35.4-51.6; head depth 38.9-47.0; upper jaw length 38.5-41.6; snout length 32.4-32.6; eye diameter 15.8-17.8; gill slit length 31.6-36.8; pectoral-fin length 51.6-60.8; interorbital width 7.6-8.9; interpupillary width 17.4-22.4; caudal-fin length 5.4-6.9; pelvic-fin length 11.9-15.3. Pectoral base/length ratio: 44.6-54.5.

Cephalic lateralis pore variation minimal; USNM 356654 with eight preoperculomandibular pores (pores 5 and 6 joined), the others with nine pores; suborbital pores 7 + 0 in SAM 34530, 8 + 0 in others; postorbital pore 1 only in all specimens; occipital and interorbital pores absent; two supraorbital (nasal) pores. Caudal-fin rays highly variable in this species (Anderson, 1988); present material with one epural, four upper hypural and three lower hypural rays in four fish; one (SAM 34600) with two epural and four upper and lower hypural rays, increasing count to 6-10 rays for the species. Lateral line ventrolateral, complete to tail tip. Dorsal-fin origin associated with vetebrae 13-14, with 8-9 free pterygiophores. Anal-fin pterygiophores inserted anterior to haemal spine of first caudal vertebra 4-6.

Remarks. Anderson (1988) redescribed this species from 14 specimens 139-257 mm SL, including the holotype of Lycenchelys atacamensis Andriashev. The present material agrees well with other specimens, but meristics are extended as USNM 356654 had the fewest vertebrae (26 + 91) encountered so far, and consequently the fewest dorsal and anal rays. Morphometric data are extended slightly for a few characters. The largest specimen here, SAM 34530, is the second known gravid female. It contained 17 ova 4.6-5.9 mm in diameter. MNHN 1990-645 extends the range of this species into the Weddell Sea.