Author: (Jordan and Gilbert, 1882)
Field Marks:
The only requiem shark in the eastern Pacific with long labial furrows and a second dorsal origin well behind the anal origin. See key to species and diagnostic features for characters separating it from other members of its genus.
Diagnostic Features:
Prenarial snout 4.5 to 6% of total length; upper labial furrows long, 2.1 to 2.6% of total length; total count of enlarged hyomandibular pores on both sides of head just behind mouth angle usually over 16 (8 to 15 on each side); teeth with serrated edges in adults; teeth not differentiated between sexes; total tooth rows usually 27 to 29/26 to 28. First dorsal origin usually over or slightly in front of pectoral free rear tips; second dorsal origin above last third of anal base in front of its insertion; pectoral anterior margin usually equal to or shorter than first dorsal length from origin to free rear tip; adpressed apex of pectoral reaches anterior third or two-thirds of first dorsal base. Posterior monospondylous precaudal centra greatly enlarged; precaudal centra variably 12 less to 8 more than caudals, precaudals 68 to 86, total counts 146 to 167. Size moderate, males maturing over 60 cm total length. Colour grey or grey-brown above, white below, pectoral fins with light edges, dorsals with dusky tips.
Geographical Distribution:
Eastern Pacific: Southern California to Peru.
Habitat and Biology:
An abundant but little-known tropical littoral shark of the continental shelves of the eastern Pacific, found at depths from the intertidal to at least 27 m depth.
Size:
Maximum at least 110 cm and possibly to 154 cm, males maturing between 58 and 69 cm and reaching at least 92 cm, adult femiaes 103 to possibly 154 cm; size at birth between 33 to 34 cm.
Interest to Fisheries:
A locally abundant shark, in some areas (as in the Gulf of California) one of the most abundant if not the most abundant of inshore sharks; fished by longline and probably other gear and utilized fresh or fresh frozen for human consumption and also for fishmeal.
Type material:
Holotype: Three syntypes in U.S. National Museum of Natural History collections: USNM 28306, 517 mm female, USNM 28330, 792 mm adult male, and USNM 29551, 518 mm female, all from Pacific Mexico. Type Locality: Mazatlan, Mexico, eastern Pacific.