Gray Smoothhound Shark: Mustelus californicus

Family: Triakidae
Common name(s)

Gray Smoothhound Shark (USA), Grey Smoothhound.


Body slender. Snout fairly long and pointed. Upper and lower labial furrows are of similar length. Small, visible spiracle behind eye. First dorsal fin origin posterior to pectoral fin free rear tip. Second dorsal fin much larger than anal fin. First and second dorsal fin margins un-frayed. Lower caudal lobe indistinct. Dorsal coloration grey-brown. Fins may be slightly dusky with a subtle white margins.

Interestingly, there are several reports of albinism in this species. Albino sharks are not that uncommon but multiple albinos of the same species is unusual. All of the records are from animals collected in Elkhorn Slough, California. One adult female contained ten embryos, five of which were albino.


Maximum length 116cm. In 1972  Miller and Lea reported a 163cm specimen but this was probably an error based on the average size of other adults. Size at birth 23-30cm.


A temperate water species inhabiting shallow muddy or sandy bays and estuaries. Present in deeper water closer to the equator. Surface to 256m. 2-45m in California.


The gray smoothhound shark is found from Northern California to the tip of the Baja Peninsula and throughout the Sea of Cortez.

Conservation Status


The brown smoothhound is taken by recreational fishers and as bycatch off California and is both targeted and caught as bycatch in trawl and gillnet fisheries off Mexico. This is a relatively fast-growing smooth-hound, with a generation length of ten years, an early age at first maturity (2-3 years for females), and moderate fecundity (3-16 pups per litter). The majority of fishing pressure on this species occurs in the southern half of its range throughout the Gulf of California, with little fishing mortality reported in the United States. While no species-specific catch data are available from the northern Gulf of California, surveys from Baja California Sur suggest that the population of Gray Smooth-hound is stable in the region. Given this survey information and the life history characteristics of this species, Gray Smooth-hound is assessed as Least Concern. However, as fishing pressure is ongoing throughout much of this species’ range, catch levels need to be quantified and catch and population trends should be monitored to ensure sustainability.

Citations and References
Pérez-Jiménez, J., Vásquez, V.E., Chabot, C.L. & Ebert, D.A. 2015. Mustelus californicusThe IUCN Red List of Threatened Species 2015: e.T161334A80672080. Downloaded on 22 October 2020.


A viviparous species with yolk-sac placenta. 7-16 pups per litter. Gestation is approximately 11 months. Birthing occurs in the Gulf of California in April-May.


Predates heavily on crustaceans (stomatopods and crabs). Also feeds on small bony fishes and molluscs.


Large aggregations of gray smoothhound sharks can be found in shallow water during the fall and winter months in central California. They are rarely seen at other times of year.

Reaction to divers

Rarely seen by divers. Retreats quickly when approached.

Diving logistics

One or two gray smoothhound sharks can sometimes be seen in the La Jolla area in the late summer, mixed in with large schools of leopard houndsharks that migrate through that area. I have seen one (in a handful of visits) while snorkeling at a spot called The Marine Room. In July-early September this a is a great place to see scores of leopard houndsharks, although the visibility is often poor and the ocean can be quite rough in the surf zone, where they are generally hunting.

Gray smoothhounds are occasionally seen from the bank and by kayakers at Elkhorn Slough Nature Reserve south of San Francisco. The water is not very clear in the muddy bay but the sharks have to traverse very shallow bars on their way into the slough so you can sometimes see their fins breaking the surface.

Similar species

Brown Smoothhound Shark Distinguished by its dorsal and caudal fins that have frayed posterior margins.

Sicklefin Smoothhound Shark Distinguished by its more falcate first dorsal fin, more pointed head, and shorter upper labial furrows.