Seleniolycus pectoralis

description

Description. Principal counts and measurements are presented in Table 1. Vertebral centra symmetrical, with prezygapophyses and postzygapophyses of equal horizontal length. Anal fin pterygiophores 3 (3 - 4), inserted anterior to haemal spine of first caudal vertebra. Caudal fin with 1 epural, 4 upper and 5 lower hypural rays. Epipleural ribs on 3 (3 - 4) to penultimate precaudal vertebra. Gill rakers on outer surface of first gill arch simple (not furcate) and with spinules. Branchiostegal rays 6. Pectoral fin wedge-shaped; its origin below body midline; lower rays thickened, exserted. Pelvic fin absent. Body elongate; trunk relatively robust, tail laterally compressed. Head ovoid, robust; anterior profile of snout almost vertical. Eyes relatively large, circular, not reaching dorsal profile of head. Mouth subterminal; lower lips without lateral lobe, upper lip continuous across snout. Snout blunt, upper jaw slightly longer than lower jaw, reaching past middle of eye. Nasal tube well developed, but not reaching upper lip. Gill slit large, extending ventrally to level of lower pectoral fin base or just below. Opercular lobe at dorsal margin of gill slit, angular and relatively promi

Two new species of eelpouts (Teleostei, Zoarcidae) of the genus Seleniolycus from the Ross Dependency, Antarctica.

diagnosis

Diagnosis. Differs from congeners by having ventralmost pectoral fin rays exserted, scales present on posterior 2 / 5 of body, dorsal fin rays 76 - 80, and anal fin rays 64 - 66. It is further diagnosed by the following combination of characters: suborbital head pores 6 - 7, preoperculomandibular pores 8; predorsal length 28.0 - 30.7 % SL; snout length 28.3 - 36.6 % HL, eye diameter 9.4 - 12.0 % HL; pectoral fin rays 14 - 16; anterior dorsal fin pterygiophore associated with vertebra 6 - 7; vertebrae 23 - 27 + 61 - 63 = 86 - 89.

Two new species of eelpouts (Teleostei, Zoarcidae) of the genus Seleniolycus from the Ross Dependency, Antarctica.

discussion

Comparison with congeners. Seleniolycus pectoralis is very similar to S. robertsi in having scales on the posterior part of the body (vs. absent in S. laevifasciatus), a relatively long predorsal distance (28.0 - 30.7 and 27.1 - 36.4 % SL vs. 20.0 - 23.8 % SL in S. laevifasciatus), and in the number of suborbital head pores (6 - 7 and 6 vs. 5 in S. laevifasciatus). Seleniolycus pectoralis differs, however, from both S. robertsi and S. laevifasciatus by the wedge-shaped pectoral fin, with exserted lower rays (vs. with no exserted rays) (Fig. 3), and in the more robust head and body which is expressed in several morphometric characters (Table 1). Seleniolycus pectoralis further differs from S. robertsi in having a longer pre-scaled distance (58.7 - 61.8 % SL vs. 48.9 - 55.4 % SL) and a larger head (19.8 - 24.6 % SL vs. 16.1 - 18.8 % SL).

Two new species of eelpouts (Teleostei, Zoarcidae) of the genus Seleniolycus from the Ross Dependency, Antarctica.

distribution

Distribution and habitat. Currently known from only four specimens, caught at two positions along the Pacific-Antarctic Ridge (64 ° 42.3 ' S, 176 ° 44.6 ' E and 63 ° 39 ' S, 173 ° 04 ' E), at depths of 1948 - 2594 m (Fig. 4).

Two new species of eelpouts (Teleostei, Zoarcidae) of the genus Seleniolycus from the Ross Dependency, Antarctica.