Hymenocephalus longipes Smith & Radcliffe, 1912

Schwarzhans, Werner, 2014, Head and otolith morphology of the genera Hymenocephalus, Hymenogadus and Spicomacrurus (Macrouridae), with the description of three new species, Zootaxa 3888 (1), pp. 1-73 : 29-30

Hymenocephalus longipes Smith & Radcliffe, 1912

Figs. 9A–G , 12

Hymenocephalus longipes Smith & Radcliffe, 1912: 109 (type locality: 09°38’N, 121°11’E).

Hymenocephalus longipes: Gilbert & Hubbs, 1920: 527 .

Material examined. 6 specimens; 1 specimen MNHN 2011–0226 , 146 mm TL, 11°57’N, 121°28’E, 388–404 m ; 2 specimens (otoliths only) USNM 99474 , 11°10’N, 121°28’E ; 1 specimen USNM 150156, 137 mm TL, 10°08’N, 123°52’E ; 1 specimen (otolith only) USNM 150157 , 10°10’N, 123°53’E ; 1 specimen USNM 150158, 155 mm TL, 08°48’N, 123°35’E ; 1 specimen (otolith only) USNM 150160 , 12°52’N, 123°23’E .

Diagnosis. Pelvic fin rays 8; pectoral fin rays 13–15; pelvic fins with black-colored tips; snout barely projecting; head bones rather firm; barbel absent; orbit diameter 28–33% HL; interorbital width 40–50% HW; gill rakers 19–21; ventral striae reaching close to periproct; OL:OH = 1.1–1.25; TCL:PCL = 1.7–2.1.

Comparison. See H. longibarbis .

Description. Head morphology (n = 3) ( Fig. 9A–C ): Head with rounded, soft-tipped snout, not projecting. Snout length 15% HL, orbit diameter 28–33% HL, interorbital width 40–50% HW. Barbel absent. Head canals well developed, infraorbital width 10–12% HL, supraorbital canal with 6 segments, width 5–10% HL, supratemporal canal indistinct, preopercular canal width 7–12% HL, postorbital-preopercular interspace 11–13% HL. Infranasal supporter small; infraorbital supporter moderately widened throughout length below orbit, expanding beyond rear part of orbit, 80–100% OD; preopercular supporter broad, blunt, with straight rear margin short (3–5% HL).

Otolith morphology (n = 7) ( Fig. 9D–G ): Otolith moderately high bodied; OL:OH = 1.1–1.25; OL:OT about 4. Predorsal lobe large, with pointed tip, triangular in shape, rather gently inclining towards rear part of otolith with some undulation. Anterior rim irregular, broadly rounded to blunt; posterior tip moderately pointed. Ventral rim deep, smooth and regularly curved, deepest anterior of middle. Inner face very slightly convex along horizontal axis, with median sulcus. Ostial and caudal colliculi moderately large, narrowly placed at collum, terminating at considerable distance from anterior and posterior tips of otolith; pseudocolliculum moderately enlarged. CCL:OCL = 0.9–1.0; TCL:PCL = 1.7–2.1. Dorsal depression wide; ventral furrow thin, close to ventral rim.

Distribution ( Fig. 12 ). Known from a relatively small area within the Sulu Sea and southern Luzon to northern Mindanao.

Figures

FIGURE 9. Hymenocephalus longipes: A–B—USNM 150156, A—Lateral view of head, B—Dorsal view of head. C—MNHN 2011-0226, lateral view of head. D–G—Otoliths, D—MNHN 2011-0226, inner face, E—MNHN 2011-0226, ventral view, F–G—USNM 150160.

FIGURE 12. Geographical distribution of Hymenocephalus longibarbis, H. longipes and H. iwamotoi.