Author: (Fowler, 1934)
Field Marks:
An Apristurus with an unusually short abdomen, long narrow caudal fin without a crest of denticles, a very long low anal fin, and second dorsal fin about half the length of first.
Diagnostic Features:
Body relatively slender, trunk slightly tapering toward head. Snout moderately long, broad, and bell-shaped, preoral snout about 9% of total length; gill slits very small, much less than eye length; gill septa somewhat incised but without pleats or projecting medial lobes; eyes rather small, about 3% of total length; nostrils broad, their width about 1.2 times in internarial space; incurrent and excurrent apertures very narrow and almost slitlike, anterior nasal flap low and angular; mouth fairly short, large, and broadly arched, with dental bands little expanded but with lower ones falling well behind uppers; mouth and labial furrows extending partly in front of eyes; labial folds somewhat enlarged, with lower nearly transverse to body axis. Interdorsal space slightly greater than first dorsal base, about half of preorbital snout; first dorsal fin about a third as large as the second, base of first about half that of second; origin of first dorsal slightly anterior to pelvic insertions; second dorsal insertion well in front of anal insertion; pectoral fins rather large, anterior margins about 14% of total length; inner margins long, nearly the length of pectoral bases; interspace between pectoral and pelvic bases extremely short, about half of preoral snout and about 6% of total length; pelvic fins fairly high and broadly rounded; anal fin very long, fairly high, and rounded-angular, nearly five times as long as high, its base about equal to prebranchial space and 19% of total length; caudal fin rather long and narrow, without a crest of enlarged denticles on dorsal margin. Lateral trunk denticles with crowns flat and close-set, body surface fairly smooth and not with a feltlike or fuzzy texture. Colour brownish without conspicuous markings. Adult size unknown.
Geographical Distribution:
Known only from the type locality.
Habitat and Biology:
A poorly known deepwater bottom shark, known only from the holotype (Cagayan Island, Jolo Sea, The Philippines).
Size:
Maximum 31cm (immature female holotype).
Interest to Fisheries:
None.
Remarks:
The writer has examined the holotype, a distinctive species closest to the single dorsal-finned Pentanchus profundicolus and possibly identical to it.
Type material:
Holotype: U.S. National Museum of Natural History, USNM, 93134, 312 mm total length, immature female. Type Locality: 9°37'N, 121°12.5'E, Cagayan Island. Jolo Sea, The Philippines.