''Squalus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of dogfish sharks in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Squalidae. Commonly known as spurdogs, these

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s are characterized by smooth dorsal fin spines, teeth in upper and lower jaws similar in size,

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

with lateral keels; upper precaudal pit usually present, and caudal fin without subterminal notch. In spurdogs, the hyomandibula (the bone connecting the braincase to the jaws) is oriented at a right angle to the

neurocranium In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the cal ...

, while in other sharks, the hyomandibula runs more parallel to the body. This led some to think that the upper jaw of ''Squalus'' would not be as protractile as the jaws of other sharks. However, a study that compared different jaw suspension types in sharks showed that this is not the case and that ''Squalus'' is quite capable of protruding its upper jaw during feeding.Wilga, C.D., Motta, P.J. & Sanford, C.P. (2007): Evolution and ecology of feeding in elasmobranchs. ''Integrative and Comparative Biology, 47 (1): 55-69.'' The name comes from ''squalus'', the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for shark; this word is the root for numerous words related to sharks such as squaline and

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

s for sharks, such as the order

Squaliformes The Squaliformes are an order of sharks that includes about 126 species in seven families. Members of the order have two dorsal fins, which usually possess spines, they usually have a sharp head, no anal fin or nictitating membrane, and fi ...

Species

Currently, 33 recognized species are placed in this genus: * ''

Squalus acanthias The spiny dogfish (''Squalus acanthias''), spurdog, mud shark, or piked dogfish is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. While these common names may apply to seve ...

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

, 1758 (spiny dogfish) * '' Squalus albicaudus'' Viana, M. R. de Carvalho & U. L. Gomes, 2016 (Brazilian whitetail dogfish) Viana, S.T.d.F., Carvalho, M.R.d. & Gomes, U.L. (2016): Taxonomy and morphology of species of the genus ''Squalus'' Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae). ''Zootaxa, 4133 (1): 1-89.'' * '' Squalus albifrons'' Last, W. T. White & J. D. Stevens, 2007 (eastern highfin spurdog) * '' Squalus altipinnis'' Last, W. T. White & J. D. Stevens, 2007 (western highfin spurdog) * '' Squalus bahiensis'' Viana, M. R. de Carvalho & U. L. Gomes, 2016 (northeastern Brazilian dogfish) * '' Squalus blainville'' ( A. Risso, 1827) (longnose spurdog) * '' Squalus brevirostris'' S. Tanaka (I), 1917 (Japanese shortnose spurdog) * '' Squalus bucephalus'' Last, Séret & Pogonoski, 2007 (bighead spurdog) * '' Squalus chloroculus'' Last, W. T. White & Motomura, 2007 (greeneye spurdog) * '' Squalus clarkae'' Pfleger, Grubbs, Cotton & Daly-Engel, 2018 (Genie's dogfish) * '' Squalus crassispinus'' Last, M. J. Edmunds & Yearsley, 2007 (fatspine spurdog) * '' Squalus cubensis'' Howell-Rivero, 1936 (Cuban dogfish) * '' Squalus edmundsi'' W. T. White, Last & J. D. Stevens, 2007 (Edmund's spurdog) * '' Squalus formosus'' W. T. White & Iglésias, 2011 (Taiwan spurdog) * '' Squalus grahami'' W. T. White, Last & J. D. Stevens, 2007 (eastern longnose spurdog) * '' Squalus griffini'' Phillipps, 1931 (northern spiny dogfish) * '' Squalus hawaiiensis'' Daly-Engel, Koch, Anderson,

Cotton Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...

, Grubbs, 2018 (Hawaiian spurdog) * '' Squalus hemipinnis'' W. T. White, Last & Yearsley, 2007 (Indonesian shortsnout spurdog) * '' Squalus hima'' Swetha, Bineesh, Beira, Das, & Bhaskar, 2024 (Indian spurdog) * '' Squalus japonicus'' Ishikawa, 1908 (Japanese spurdog) * '' Squalus lalannei'' Baranes, 2003 (Seychelles spurdog) * '' Squalus lobularis'' Viana, M. R. de Carvalho & U. L. Gomes, 2016 (Atlantic lobefin dogfish) * '' Squalus megalops'' ( W. J. Macleay, 1881) (shortnose spurdog) * '' Squalus melanurus'' Fourmanoir & Rivaton, 1979 (blacktailed spurdog) * '' Squalus mitsukurii'' D. S. Jordan & Snyder, 1903 (shortspine spurdog) * '' Squalus montalbani'' Whitley, 1931 (Indonesian greeneye spurdog) * '' Squalus nasutus'' Last, L. J. Marshall & W. T. White, 2007 (western longnose spurdog) * '' Squalus notocaudatus'' Last, W. T. White & J. D. Stevens, 2007 (bartail spurdog) * '' Squalus quasimodo'' Viana, M. R. de Carvalho & U. L. Gomes, 2016 (humpback western dogfish) * '' Squalus rancureli'' Fourmanoir & Rivaton, 1979 (Cyrano spurdog) * '' Squalus raoulensis'' Duffy & Last, 2007 (Kermadec spiny dogfish) *'' Squalus shiraii'' Viana & M. R. de Carvalho, 2020 (Shirai's spurdog) * '' Squalus suckleyi'' ( Girard, 1855) (Pacific spiny dogfish) Image:Spiny dogfish.jpg, ''

'' Image:Squalus altipinnis.jpg, '' Squalus altipinnis'' Image:Squalus blainville.jpg, '' Squalus blainville'' Image:Squalus bucephalus JNC2621 Body.JPG, '' Squalus bucephalus'' Image:Squalus chloroculus.jpg, '' Squalus chloroculus'' Image:Squalus crassispinus.jpg, '' Squalus crassispinus'' Image:Squalus cubensis eits.jpg, '' Squalus cubensis'' Image:Squalus megalops.jpg, '' Squalus megalops'' Image:Squalus melanurus JNC2719 Body.JPG, '' Squalus melanurus'' Image:HutoTZ.jpg, '' Squalus mitsukurii''

References

{{Authority control Extant Campanian first appearances Taxa named by Carl Linnaeus

Species

See also

References