Mustelus californicus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Carcharhiniformes Triakidae

Scientific Name: Mustelus californicus Gill, 1864
Common Name(s):
English Gray Smooth-hound
Taxonomic Source(s): Eschmeyer, W.N. and Fricke, R. (eds). 2015. Catalog of Fishes: genera, species, references. Updated 1 October 2015. Available at: (Accessed: 1 October 2015).
Taxonomic Notes: Shark species within the genus Mustelus are very similar in both appearance and size, making proper identifications challenging. Five species of Mustelus are known to frequent the waters surrounding Baja California. One of these five species, M. albipinnis, was only recently described and has likely been misidentified in the past as other Mustelus spp. (Castro-Aguirre et al. 2005, Pérez-Jiménez et al. 2005). Mustelus albipinnis is distinguished from M. californicus by white margins present on its fins and a habitat preference for deeper waters (Castro-Aguirre et al. 2005, Pérez-Jiménez et al. 2005, Ebert et al. 2013). Another Baja California smooth-hound, M. lunulatus is considered to be the most similar to M. californicus due to similar colour patterns (grey dorsal colouration with a lighter ventral side). Mustelus lunulatus can be distinguished from M. californicus by its wider set eyes, longer snout and shorter upper labial furrows (Pérez-Jiménez et al. 2005, Ebert et al. 2013). Both species, however, have well developed lower caudals and molariform teeth (Ebert et al. 2013). Dentition can be used to distinguish M. californicus from both M. dorsalis and M. henlei which both have sharper high-cusped teeth (Starks 1917, Pérez-Jiménez et al. 2005, Ebert et al. 2013). Mustelus henlei can also be differentiated by the dorsal fins, which are frayed at the posterior margins and more anteriorly placed along the body than M. californicus (Starks 1917, Ebert 2003, Ebert et al. 2013).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2014-03-19
Assessor(s): Pérez-Jiménez, J., Vásquez, V.E., Chabot, C.L. & Ebert, D.A.
Reviewer(s): Nosal, A.P., Carlisle, A.B. & Cordova, J.
Facilitator/Compiler(s): Lawson, J., Walls, R.H.L. & Dulvy, N.K.
Gray Smooth-hound (Mustelus californicusranges from Cape Mendocino, northern California to Mazatlan, Mexico in the southeastern Gulf of California, Eastern Central Pacific. It is demersal and usually occurs in shallow waters, from 8 m depth, but has been found offshore to depths of 265 m. This species is viviparous, with a yolk sac placenta. It 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.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Gray Smooth-hound is found in the eastern central Pacific Ocean, ranging from Cape Mendocino in northern California to Mazatlan, Mexico in the southeastern Gulf of California (Ebert 2003).
Countries occurrence:
Mexico; United States (California)
FAO Marine Fishing Areas:
Pacific – eastern central
Additional data:
Lower depth limit (metres):67
Upper depth limit (metres):12
Range Map:Click here to open the map viewer and explore range.

Population [top]


In the artisanal elasmobranch fishery of Baja California Sur, Mexico a ten-year survey (2000-2010) found Grey Smooth-hound to be most abundant during the summer and autumn seasons and distributed along the entire coast. While this shark, when identified to species-level, represented a low proportion of total annual catch records regardless of gear type (Gray Smooth-hound represented 192 out of 10,682 sharks caught), the general genus category of Mustelus was by far the most well-represented of the total 455 undetermined elasmobranch species with 404 individuals listed under this genus. Morphological similarities among members of the genus Mustelus can lead to identification errors. Thus it should also be noted that during this survey a reported total catch of 78 individuals of M. lunulatus were recorded, which is the species most similar in appearance to Gray Smooth-hound. In addition, one of the most commonly taken elasmobranchs (taken specifically by gill nets) was another species of related smooth-hound, M. henlei, with a total of 3,233 individuals caught (Ramirez-Amaro et al. 2013). Catches of Grey Smooth-hound over this ten-year survey period in Baja California Sur, Mexico were reported to be stable (Galván-Magaña, 2015, pers. comm.). Within the official Mexican fisheries catch and fishing effort data, species-specific data are lacking for elasmobranchs (Pérez-Jiménez and Sosa-Nishizaki 2010). Currently, there are only three recognized elasmobranch categories: a) Sharks (sharks >150 cm total length (TL)); b) Cazones (sharks < 150 cm TL) and Rays (all batoids; Ramirez-Amaro et al. 2013).

Marquez-Farias (2000) reported that Gray Smooth-hound and other small shark species (Rhizoprionodon longurioM. lunulatus and M. henlei) in Sonora state (northeastern Gulf of California) are sometimes caught in numbers as high as 1,200-1,500 individuals per fishing trip. In three regions of the Gulf of California (Southeastern, Central and Northern) the highest catches of Gray Smooth-hound obtained by a trawler vessel (operating at depths of 1-200 m) were: a) 51 kilograms per hour (kg/h-1) during February-March at depths of 41-80 m in the Southeastern Gulf of California (Sonora and Sinaloa coasts); b) 106.43 kg/ h-1 during September at depths from 81-120 m in the Central Gulf of California (Midriff Islands) and; c) 186 kg/h-1 during May at depths of 81-120 m in the Northern Gulf of California (Ehrhardt et al. 1980). Although these authors state that these catches only included M. californicus, they may also have included M. lunulatus in shallower areas (from 1-80 m) and M. henlei in deeper areas (from 80-200 m). In Santa Rosalillita, Baja California (approximately 400 km south of Ensenada) 4,638 kg of Mustelus species were caught from May to September 2001 (Rodríguez-Medrano and Almeda-Jauregui 2002).

Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:

This species is found both inshore and offshore in warm-temperate to tropical waters. It is demersal on continental shelves and enters shallow muddy bays (Ebert 2003, Ebert et al2013). It moves into north-central California waters in summer, but is resident in warmer waters from southern California and south to Mexico (Ebert 2003, Ebert et al2013). In California it is usually found in water < 12 m deep, but has been caught at a depth of 67 m (Sandell 1973, Ebert 2003). In the northern Gulf of California, the species has been caught at depths ranging between 6-265 m with the majority of catches occurring at depths < 80 m where the species is abundant (Pérez-Jiménez et al. 2010). 

This shark tends to travel in schools and has often been observed to congregate with Leopard Shark (Triakis semifasciata) in very shallow water (Ebert 2003). Marquez-Farias (2000) report that this smooth-hound and other small shark species (including Rhizoprionodon longurioM. lunulatus and M. henlei), make seasonal migrations in Sonora state (northeastern Gulf of California) during the autumn and winter months. Espinoza et al. (2011) found this shark to be a seasonal resident of the Full Tidal Basin of Bolsa Chica, California with higher abundance during summer months and a high proportion of immature individuals. Elkhorn Slough and Anaheim Bay, California have both been described as nursery areas for this species. In Elkhorn Slough, parturition occurs from January to May (Yudin 1987). In Anaheim Bay, mating reportedly occurs from February to June and parturition from March to June (Sandell 1973). In the Upper Gulf of California, mating and parturition is thought to occur from March to June and the region is considered a nursery area for this species (Pérez-Jiménez 2006).

This species is live-bearing with a yolk sac placenta and litter sizes range between 3-16 pups (Talent 1985, Yudin 1987, Pérez-Jiménez 2006, Ebert et al. 2013). Reproduction is annual and gestation takes about 10-12 months (Sandell 1973, Yudin 1987, Pérez-Jiménez 2006). Data from central California indicates that males mature at 57-65 cm total length (TL; Yudin and Cailliet 1990), and data from the Northern Gulf of California suggests they mature at 72-74 cm TL (Pérez-Jiménez 2006, Pérez-Jiménez and Sosa-Nishizaki 2010). Females mature at 70-90 cm TL (Yudin and Cailliet 1990, Pérez-Jiménez 2006, Pérez-Jiménez and Sosa-Nishizaki 2010). The maximum recorded size for this species is 160 cm TL (Eschmeyer et al. 1983). Males mature between 1-2.5 years of age, females mature between 2-3 years of age, and the maximum observed lifespan is nine years (Yudin and Cailliet 1990, Pérez-Jiménez 2006, Ebert et al. 2013). Size at birth is 20-30 cm (Sandell 1973, Talent 1985, Yudin 1987, Yudin and Cailliet 1990, Pérez-Jiménez 2006). In the Northern Gulf of California, all young-of-the-year were found to be 49 cm TL or smaller. Average reproductive age is estimated at 4.6 years of age (Cortés 2002). Generation length is estimated to be 11 years (Chen and Yuan 2006).


Use and Trade [top]

Use and Trade: Not known to be utilized.

Threats [top]

Major Threat(s): In the USA this species is regularly caught by recreational anglers in southern California and is of little economic value (Ebert 2003). The California Department of Fish and Wildlife reports <1 metric tonne of Grey Smooth-hound being landed by the commercial fisheries in 2013 (California Department of Fish and Wildlife, 2014).
The majority of the fishing pressure on Gray Smooth-hound occurs in Mexico, specifically in the Gulf of California. In Baja California, Mustelus species have been caught by the artisanal fishing fleet in the northern Gulf of California since the 1980s (Cudney and Turk 1998) and by the medium size trawl fleet since 1996, when 59 shrimp trawler vessels obtained fishing permits to catch finfish and elasmobranch species out of the shrimp fishing season. When they are not being targeted, they are taken as bycatch by the shrimp trawl fleet (Sustentabilidad y Pesca Responsible en México: Evaluación y manejo 1997-1998). No catch data are available but these trawl vessels operate in shallow waters where this species is present. In addition to trawl vessels, this species is frequently targeted with bottom gill-nets (4-6 inches mesh size) in the northern Gulf of California from March to July, especially when most valuable teleost species are not abundant. Neonates are not thought to be vulnerable to the gill-nets used because they are smaller than the mesh size (4, 6, 8 inches) in this area. In this region the catches can be as high as 500 kg per fishing trip. In the Baja California Sur, this species is commonly caught in the southern Gulf of California by medium size trawl vessels that target finfish and elasmobranchs from April to July (at depths shallower than 100 m), and is bycatch in the shrimp fishery from September to January (Pérez-Jiménez 2006).

Conservation Actions [top]

Conservation Actions: There are no specific management measures in place for this species. 

After the 2006 restoration of the Full Tidal Basin of Bolsa Chica, California, immature individuals of this species became seasonal residents (Espinoza et al. 2011). This shark utilizes the area by day for warm water temperatures then apparently forages at night (Espinoza et al. 2011). Though the area does not yet meet all the criteria for a nursery ground (Heupel et al. 2007), this wetland restoration project still appears to be of ecological importance to juveniles of this species (Espinoza et al2011).

A set of national regulations, the Mexican Official Standard Rules for Shark and Ray responsible fisheries (NOM-029-PESC-2004-2006) entered into place in May 2007. These rules state that every individual kept aboard commercial shark fishery vessels must be used entirely, however, oceanic vessels may discard the shark guts and head and shark finning is prohibited. No information is available on how effectively these measures are enforced.

Citation: Pérez-Jiménez, J., Vásquez, V.E., Chabot, C.L. & Ebert, D.A. 2015. Mustelus californicus. The IUCN Red List of Threatened Species 2015: e.T161334A80672080. . Downloaded on 24 September 2018.
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