Author: (Tanaka, 1909)
Field Marks:
One of several Apristurus with the first dorsal fin half area of second or less. See diagnostic features and key to species for further characters.
Diagnostic Features:
Body relatively slender, trunk slightly tapering toward head. Snout moderately long, broad, and bell-shaped, preoral snout about 8% of total length; gill slits small, less than eye length; gill septa without projecting medial lobes or pleats, not strongly incised; eyes rather small in adults; about 3% of total length; nostrils broad, their width about 1.2 times internarial space; incurrent and excurrent apertures narrowly oval, anterior nasal flaps low and angular; mouth short, moderate-sized, and broadly arched, with dental bands little expanded and with lower one falling just behind uppers; mouth and labial furrows mostly below ovoc- Inhinl fnidc nnt PnlarnPd with Inwars diannnal to body axis. Interdorsal space about twice first dorsal base, slightly less than preorbital snout; first dorsal fin about half as large as second, base of first about two-thirds length of second; origin of first dorsal posterior to pelvic insertions; second dorsal insertion well in front of anal insertion; pectoral fins moderate-sized, anterior margins about 14% of total length; inner margins long, nearly length of pectoral bases; interspace between pectoral and pelvic bases short, sligthly less than prespiracular length and about 10% of total length in adults; pelvic fins fairly high and broadly rounded; anal fin long, low and subangular, about five times as long as high, base slightly greater than prebranchial space and 19% of total length in adults; caudal fairly broad, without a dorsal crest of enlarged denticles. Lateral trunk denticles of body with crowns flat and closely imbricating, surface smooth and without a feltlike or fuzzy texture. Colour probably dark, without conspicuous markings. Adults moderately large, adult female 64 cm.
Geographical Distribution:
Western North Pacific: Japan (Honshu).
Habitat and Biology:
A little-known deepwater species of the continental slopes. Oviparous, probably one egg per oviduct laid at a time.
Size:
Maximum about 80 cm.
Interest to Fisheries:
None at present.
Type material:
Holotype: Imperial University collection, Tokyo, Japan, no. 2154, 800 mm male, presumably adult. Type Locality: Off Japan.