White-line Eelpout

description

(Figs. 1 and 2) “ Espécie indeterminada 1 ” [unidentified species 1]. — Bernardes et al., 2005: 242 [five specimens, 197 – 217 mm, off Cabo de Santa Marta, 490 m].

A new genus and species of eelpout (Teleostei: Zoarcidae) from Brazil

description

Description. Nine specimens: three adult males, a juvenile male, four adult females and a juvenile female. Head ovoid, deeper across nape in adults than juveniles. No sexual dimorphism of head width detected. Scales and epidermal prickles absent. Eye rounded, not entering dorsal profile of head. Gill slit extending ventrally to opposite second to fourth from lowermost pectoral-fin ray. Gill slit posterodorsally inclined, no opercular flap at upper end. Pectoral-fin origin well below body midline, insertion on abdomen; posterior margin of fin rounded, ventralmost rays slightly exserted, lowermost 5 – 6 rays slightly thickened. Mouth subterminal in juveniles, inferior in adults. Upper jaw extending to middle of eye or slightly beyond it. Upper lip broadly adnate to snout tip and coalesced with thickened flesh of cheek, lower lip lobe weak. Nasal tube short, not reaching upper lip when pressed forward. Oral valve weak, not reaching anterior edge of vomer and coalesced with lateral margin of palate before posterior corner of rictus. Jaw teeth small, conical, premaxillae with 2 – 3 irregular rows of teeth anteriorly, blending into single posterior row; dentaries with 3 – 5 irregular too

A new genus and species of eelpout (Teleostei: Zoarcidae) from Brazil

diagnosis

Diagnosis. As for the genus. Counts and proportions. Holotype followed parenthetically by the range of the paratypes. Vertebrae 24 + 65 = 89 (23 – 26 + 62 – 66 = 85 – 92); dorsal-fin rays 85 (81 – 86); anal-fin rays 64 (62 – 67); caudal-fin rays 9 (9); pectoral-fin rays 17 (16 – 18); pelvic-fin rays 2 (2); vomerine teeth 11 (6 – 10); palatine teeth (left / right) 8 / 7 (6 – 12 / 6 – 12); gill rakers 2 + 14 = 16 (1 – 3 + 13 – 14 = 14 – 17); branchiostegal rays 6 (6); pseudobranchial filaments 5 (4 – 7). Following proportions as percent SL: head length 19.5 (20.0 – 23.0); head width 11.4 (7.9 – 11.5); head depth 11.7 (10.3 – 13.3); pectoral-fin length 12.3 (11.5 – 12.8); predorsal length 21.5 (21.2 – 24.3); preanal length 47.2 (47.5 – 51.7); body depth 12.8 (10.3 – 13.0); gill slit length 6.1 (5.6 – 7.8). Following proportions as percent HL: head width 58.3 (38.3 – 54.9); head depth 60.1 (49.5 – 62.8); upper jaw length 57.5 (49.8 – 57.0); pectoral-fin length 63.2 (52.2 – 60.7); snout length 21.5 (18.8 – 28.6); eye diameter 14.8 (6 adults: 12.8 – 17.0; 2 juveniles: 20.6 – 21.0); gill slit length 31.1 (26.8 – 37.0); interorbital width 9.8 (6.8 – 9.0); interpupillary width 31.1 (25.6 –

A new genus and species of eelpout (Teleostei: Zoarcidae) from Brazil

discussion

Discussion. On the basis of its restricted gill slit, two pelvic-fin rays, weak oral valve, lack of scales and submental crests on the dentary and six branchiostegal rays, the new genus keys to Dieidolycus Anderson, 1988 in Anderson (1994 a). Dieidolycus, a rare, lower bathyal genus (1957 – 3040 m) is known from only 12 specimens representing three Southern Ocean species (Anderson, 1988, 1994 b, 2006, Anderson and Pequeño, 1998). Leucogrammolycus differs markedly from Dieidolycus chiefly in its firm flesh with head and body striping (vs. gelatinous, unpigmented flesh in Dieidolycus), its minute head pores (vs. enlarged pores in Dieidolycus), its adnate upper lip (vs. free lip in Dieidolycus), its double lateral line (vs. single lateral line in Dieidolycus), its greater number of vertebrae (85 – 92 in Leucogrammolycus vs. 78 – 81 in Dieidolycus), the first anal-fin pterygiophore associating with the first or second caudal vertebrae (vs. associating with the last precaudal vertebra in Dieidolycus), and the presence of a pseudobranch (absent in Dieidolycus).

A new genus and species of eelpout (Teleostei: Zoarcidae) from Brazil