|Scientific Name:||Apristurus brunneus (Gilbert, 1892)|
Catulus brunneus Gilbert, 1892
|Taxonomic Source(s):||Eschmeyer, W.N. and Fricke, R. (eds). 2015. Catalog of Fishes: genera, species, references. Updated 1 October 2015. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 1 October 2015).|
|Taxonomic Notes:||The genus Apristurus contains at least 32 described species and a relatively large number of potentially undescribed ones. Morphological conservatism and, until recently, a lack of objectively defined characters makes this one of the most taxonomically confused shark genera (Compagno 1984, Nakaya and Sato 1999).
Nakaya and Sato (1999) defined three species groups within Apristurus: the longicephalus-group (two species), brunneus-group (20 species) and spongiceps-group (10 species). The brunneus-group is characterized by: a short, wide snout (prenarial length <6% total length (TL), 0.36 to 0.94 times in interorbital); 13 to 22 valves in the spiral intestine; upper labial furrows obviously longer than the lower furrows; a discontinuous supraorbital sensory canal.
Compagno (1984) considered it likely that the specimens and records of A. brunneus from the western North Pacific represent an assemblage of two or more brunneus-like species.
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Huveneers, C., Duffy, C.A.J., Cordova, J. & Ebert, D.A.|
|Reviewer(s):||Jew, M.L. & Nehmens, M.C.|
|Facilitator/Compiler(s):||Lawson, J., Walls, R.H.L. & Dulvy, N.K.|
Brown Catshark (Apristurus brunneus) is a little-known deepwater catshark from the outer continental shelf and upper slope of the Eastern Pacific, known from depths of 33-1,298 meters. This species is oviparous with an egg incubation period of possibly two years or more. Size at 50% maturity is reported to be 514 mm total length for males, and 501 mm total length for females, however maturity varied by latitude in females with those at lower latitudes reaching maturity more quickly than those at higher latitudes. Although this catshark is reported to be a relatively common bycatch in deepwater trawl fisheries, insufficient catch and biological information are available to assess its extinction risk beyond Data Deficient. Species-specific monitoring of catches should be undertaken.
|Previously published Red List assessments:|
|Range Description:||Brown Catshark is found in the eastern Pacific Ocean from southern Alaska (Wilson and Hughes 1978) to southern California (Roedel and Ripley 1950) and the Gulf of California (Taylor 1972). It is also found in Central and South America in Panama, Ecuador, Peru, and Chile (Andrade and Pequeno 2008, Ebert et al. 2013, Bustamante et al. 2014).|
Native:Canada (British Columbia); Chile; Costa Rica; Ecuador; Guatemala; Honduras; Mexico (Baja California, Baja California Sur); Nicaragua; Panama; Peru; United States (Alaska, California, Oregon, Washington)
|FAO Marine Fishing Areas:|
Present - origin uncertain:
Pacific – northeast; Pacific – southeast; Pacific – eastern central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This catshark is considered abundant from British Columbia, Canada to northern and southern California (Roedel 1951, Cross 1988, Castro 2011).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Brown Catshark is a little-known demersal and mid-water deepwater shark that occurs on the outer continental shelf and upper slope from depths of 33-1,298 m. It inhabits cold water (5-8°C), and thus tends to occur shallower in the northern parts of its range (i.e., 137-360 m off British Columbia; Castro 2011) and deeper in southern parts of its range (i.e., 656-932 m off southern California; Roedel 1951).|
Reproduction is oviparous with a single egg at a time per oviduct and an incubation period of possibly two or more years (Flammang 2005). Egg cases are about 5 cm long and 2.5 cm wide, with long tendrils that are probably used to attach them to hard substrates and/or biogenic structures. Within the Monterey Bay Canyon possible nursery grounds were identified to be locations at the shelf-slope break, upper continental slope, high vertical relief with rugose substrate, and circulation water currents (Flammang et al. 2011). In Canadian waters females carry egg cases from February to August, but are usually gravid in all months in the southern regions (Flammang et al. 2008, Ebert et al. 2013). Size at hatching is estimated to be 7 cm (Clemens and Wilby 1946). Size at 50% maturity is reported to be 514 mm total length (TL) in males, and 501 mm TL in females, however maturity varied by latitude in females with those at lower latitudes reaching maturity more quickly than those at higher latitudes (Flammang et al. 2008).
|Use and Trade:||This species is not known to be utilized.|
|Major Threat(s):||Brown Catshark is commonly taken as bycatch in deepwater trawl fisheries. Deepwater fisheries have expanded at an annual rate of 62.5 m depth per decade from 1950-2004 (Watson and Morato 2013). If they continue to expand the impact on this species should be assessed. Species-specific identification is often challenging due to the soft bodies of these sharks, which are often damaged during the fishing process (Castro 2011).|
|Conservation Actions:||There are no management measures currently in place for this species.|
Andrade, I. and Pequeno, G. 2008. Mesobathic chondrichthyes of the Juan Fernandez seamounts: are they different from those of the central Chilean continental slope? Revista de biologia tropical 56(1): 181-190.
Bustamante, C., Vargas-Caro, C. and Bennett, M.B. 2014. Not all fish are equal: functional biodiversity of cartilaginous fishes (Elasmobrnachii and Holocephali) in Chile. Journal of Fish Biology 85(5): 1617-1633.
Castro, J.I. 2011. The Sharks of North America. Oxford University Press, New York.
Clemens, W.A. and Wilby, G.V. 1946. Fishes of the Pacific coast of Canada. Fisheries Research Board Canadian Bulletin 68: 368.
Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fisheries Synopsis No. 125, Volume 4, Part 1.
Cross, J.N. 1988. Aspects of the biology of two scyliorhinid sharks, Apristurus brunneus and Parmaturus xaniurus, from the upper continental slope off Southern California. Fisheries Bulletin 86: 691-702.
Ebert, D.A., Fowler, S. and Compagno, L. 2013. Sharks of the World. Wild Nature Press, Plymouth.
Flammang, B.E., Ebert, D.A., and Cailliet, G.M. 2008. Reproductive biology of deap-sea catsharks (Chondrichthyes: Scyliorhinidae) in the eastern north pacific. Environmental Biology of Fishes 81: 35-49.
Flammang, B.E., Ebert, D.A. and Cailliet, G.M. 2011. Intraspecific and Interspecific Spatial Distribution of Three Eastern North Pacific Catshark Species and Their Egg Cases (Chondrichthyes: Scyliorhinidae). Breviora 525: 1-18.
IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: www.iucnredlist.org. (Accessed: 19 November 2015).
Nakaya, K. and Sato, K. 1999. Species grouping within the genus Apristurus (Elasmobranchii: Scyliorhinidae). In: B. Séret and J.-Y. Sire (eds). Proceedings of the 5th Indo-Pacific Fish Conference (Nouméa, 3-8 November 1997). Paris, Society Francaise d’Ichthyologie et Instutue de Recherches pour le Development: 307–320.
Roedel, P. 1951. The brown shark, Apristurus brunneus, in California. California Fish and Game 37: 61-63.
Roedel, P. M. and W. E. Ripley. 1950. California sharks and rays. California Department of Natural Resources, Division of Fish and Game. Fisheries Bulletin 75(1-88).
Taylor, L.R. 1988. Apristurus kampae, a new species of scyliorhinid shark from the eastern Pacific Ocean. Copeia 1972: 71-78.
Watson, R.A. and Morato, T. 2013. Fishing down the deep: Accounting for within-species changes in depth of fishing. Fisheries Research 140: 63-65.
Wilson, D.E. and Hughes, G.W. 1978. The first record of the brown cat shark, Apristurus brunneus (Gilbert, 1891) from Alaskan waters. Syesis 11: 283.
|Citation:||Huveneers, C., Duffy, C.A.J., Cordova, J. & Ebert, D.A. 2015. Apristurus brunneus. The IUCN Red List of Threatened Species 2015: e.T44209A80671448.Downloaded on 24 October 2017.|
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