Species: Etmopterus pusillus, Smooth lanternshark

Etmopterus pusillus (Lowe, 1839)

Smooth lanternshark

Body slender; head and snout flattened, short, thick, at level of eyes head is wider than deep; snout short, thick, flat, broadly rounded; no nictitating eyelids; spiracle large, behind eye; mouth short, at acute angle; upper teeth with a long, central point plus generally 2 (female)-4 (male)  smaller points on each side, 23-31 rows, lower teeth compressed and blade-like, with small, oblique tips that do not become more erect in large fish, particularly males, 30-53 rows; five gill slits, all before pectoral base, relatively long; two dorsal fins, second bigger than first, both with long thick grooved spines; first dorsal located behind pectorals, distance from pectoral axil to 1st dorsal >1/3 interdorsal space,  center of first dorsal nearer pectoral fin axil than origin of pelvics; 1st dorsal spine short, slender, < 1st dorsal base; pectoral small, rounded to angular; no anal fin; no ridges between pectoral and pelvic fins, no precaudal pits, no keel on tail base; tail short, broad tail fin strongly asymmetrical, notch at top; denticles on sides of body without points, block-like, wide-spaced, not arranged in rows, skin smooth.

Dark brown to blackish, a little darker below; a small white blotch between eyes; fins with light edges; conspicuous dark areas on side of head, above & behind pelvic fin, at lower origin of tail fin, on underside of pectoral; luminescent organs visible as black dots and streaks on underside of head and body.

Size: 50 cm.

Habitat: Outer continental shelf and upper slopes; partly epipelagic in open ocean.

Depth: 0-1998 m.

Atlantic: Gulf of Mexico; records from the Indo-Pacific may be another species.