Author: (Engelhardt, 1912)
Diagnostic Features:
A stout-bodied lanternshark with a moderately long tail, distance from pelvic insertions to ventral caudal origin about as long as from tip of snout to spiracles, about 2 times in distance between pectoral and pelvic bases, and about 1.5 times interdorsal space; distance between pectoral and pelvic bases moderately long in adults, about 1.2 times head length; distance from snout tip to first dorsal spine about equal to distance from first dorsal spine to second dorsal rear tip. Head width about 1.5 times preoral snout; prespiracular length about equal to distance from spiracles to pectoral origins; gill openings fairly large, wider than spiracle, 1/2 eye length; upper teeth generally with less than 3 pairs of cusplets. Origin of first dorsal fin behind free rear tips of pectoral fins, dorsal fin base somewhat closer to pectoral bases than pelvics; interdorsal space short, almost equal to head length, to pectoral midbases; second dorsal fin larger than first, its area about half again that of first; distance between second dorsal base and upper caudal origin about 2 in interdorsal space; caudal fin moderately long, length of dorsal caudal margin about equal to head length. Lateral trunk denticles with slender hooked conical crowns, wide-spaced but not arranged in regular longitudinal rows; snout largely covered with denticles; no rows of greatly enlarged denticles on flanks above pectoral fins. Distal margins of fins largely covered with skin, not fringed with naked ceratotrichia. Colour dark brown or grey-brown, with inconspicuous dark lower surface and a broad, elongated mark on tail above pelvic fins.
Geographical Distribution:
Western North Pacific: Japan(southeastern Honshu).
Habitat and Biology:
A little-known lanternshark, biology almost unknown.
Size:
Maximum total length at least 53 cm, adult males to 48 cm, adult females to 53 cm.
Interest to Fisheries:
None at present.
Remarks:
The account of this species is based on Abe's (1965) redescription.
Type material:
Holotype: 550 mm female. Type Locality: Sagami Bay, Honshu, Japan.