Featured Elasmobranch- Sicklefin Smoothhound Shark
Category : Featured Elasmobranch
Copyright: Photographer/SFTEP, 2002/www.discoverlife.org
Sicklefin Smoothhound Shark
Mustelus lunulatus (Jordan & Gilbert 1882)
Family Triakidae (Houndsharks)
Identification: Head short, narrow, eyes small, internarial space broad, mouth long, and upper labial furrows shorter than lower. Teeth blunt, pebble-like, and numerous. First dorsal fin originates over the pectoral fins. Lower caudal lobe long, pointed, and “sickle-shaped”. Dorsal surface is gray to olive brown with no spotting or other distinguishing marks; ventral surface lighter.
Size: One of the largest Mustelus sharks in the eastern Pacific with a maximum length of at least 162 cm for females and 129 cm for males. Birth size 28 to 34 cm.
Distribution: This species ranges from southern California (abundant in warm-water years) to the Gulf of Panama. They are common in the Gulf of California southward to Panama and possibly Columbia.
Habitat: A little is known hound shark usually found nearshore in warm temperate to tropical waters of the eastern Pacific. It occurs close to the bottom, usually at depths of less than 100m, but down to at least 200 m.
Biology: Reproductive mode viviparous species, producing 6–19 pups annually after an 11 month gestation period. Fifty percent of females are mature at about 103 cm and males at 97 cm. In coastal Mexican waters birth usually occurs from February to May. An abundant fast-growing species, it has a low longevity and an early age at first maturity. The diet mainly consists of crustaceans, cephalopods, and teleosts.
General Interest: In California uncommon and of little commercial value. In Mexican waters Mustelus species, including the sicklefin houndshark is taken in coastal shark fisheries, but do to difficulty in identifying this species from other houndshark species catch abundance is unknown. The origin of the name comes from the sickle-shaped posterior fin edges. This species is listed as “Least Concern” on the IUCN Red List.
Jennifer S. Bigman
Graduate Student – Ichthyology
Pacific Shark Research Center
Moss Landing Marine Laboratories
8272 Moss Landing Road
Moss Landing, CA 95039