Author: Gilbert, 1891
llyophis brunneus Gilbert, 1891
Diagnosis: body greatly elongate, slender, compressed posteriorly, its depth uniform from pectoral region to near the tail tip. Head conical, snout slightly prominent. Anterior nostril tubular, subterminal; posterior nostril a collared pore in advance of eye. Mouth terminal, its cutaneous crease extending for about one eye diameter beyond posterior margin of eye; lips absent. Teeth conical, acute, slightly recurved, multiserial anteriorly, smaller and cardiform posteriorly on both jaws, larger sized teeth on premaxillary-ethmoid oval patch confluent with an irregular uniserial vomerine row, the anterior ones very large. Dorsal and anal fins well developed, confluent with caudal fin; dorsal fin origin over pectoral fin base; pectoral fin minute, only a little longer than eye. Lateral line with 35-38 preanal pores of which 4-6 prepectoral pores; cephalic system with 3 supra-orbital, 5-6 (usually 5) infra-orbital and 9-10 preoperculo-mandibular pores; no post-orbital or supra-temporal pores. Vertebrae 132-158. Scales, when present, all over the body, except on head, minute, very elongate, disposed in a 'basketwork' pattern. Colour: black to brown; fins darker; pores in lateral line white. Size: to 54 cm.
Habitat: benthopelagic on lower slope near upper abyssal zone, down to 3,120 m. Reproduction: very few data.
Distribution: probably throughout area. Elsewhere, recorded from central Atlantic, northern Indian Ocean, central eastern Pacific.
Eggs, larvae and young stages. No data.
Otoliths (sagitta). No data.