Author: Bigelow, et al., 1953
Field Marks:
Two spined dorsal fins, no anal fin, bladelike unicuspidate teeth in lower jaw and teeth with cusps and cusplets in upper jaw, very slendercrowned lateral trunk denticles, first dorsal fin far behind pectorals and about equidistant between pectoral and pelvic bases, no enlarged thorns on flanks, fins with highly fringed distal webbing.
Diagnostic Features:
A slender lanternshark with a moderately short tail, distance from pelvic insertions to ventral caudal origin slightly less than from tip of snout to first gill openings, 1.5 times in distance between pectoral and pelvic bases, and 0.6 times interdorsal space; distance between pectoral and pelvic bases moderately long in adults, about 1.1 to 1.3 times head length; distance from snout tip to first dorsal spine nearly or quite equal to distance from first dorsal spine to dorsal caudal margin. Head width about 1.4 times preoral snout; prespiracular length about equal to distance from spiracles to pectoral origins; gill openings very short, about as wide as spiracle, 1/3 eye length or less; upper teeth generally with less than 3 pairs of cusplets. Origin of first dorsal fin well behind free rear tips of pectoral fins, dorsal fin base about equidistant between pectoral and pelvic bases or somewhat closer to pectorals; interdorsal space short, about as long as distance from snout tip to first gill slits or less; second dorsal fin much larger than first, about twice its area; distance between second dorsal base and upper caudal origin betewen 1 to 1.5 times in interdorsal space; caudal fin moderately long, length of dorsal caudal margin about equal to or somewhat greater than head length. Lateral trunk denticles with very slender, hooked conical crowns, widespaced 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 naked and with a prominently fringed margin of naked and distally separated ceratotrichia. Colour light brown above, with underside of snout and abdomen dusky grey, with an elongated narrow dusky mark running above and behind pelvic fins, and elongated black marks at caudal fin base and along its axis.
Geographical Distribution:
Western North Atlantic: Northern Gulf of Mexico, Texas to Florida (USA), Mexico.
Habitat and Biology:
A lanternshark from the upper continental slopes, on or near bottom at depths of 384 to 732 m.
Size:
Maximum total length about 30 cm; adult males 27 cm long, females 28 to 30 cm.
Interest to Fisheries:
None at present.
Type material:
Holotype: U.S. National Museum of Natural History, USNM 113381, 270 mm adult or adolescent male. Type Locality: Northern Gulf of Mexico, 29°11'N, 86° 53'W, 558 m depth.