''Squalus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

dogfish shark Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned t ...

s in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Squalidae Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned t ...

. Commonly known as spurdogs, these

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

s are characterized by smooth

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

spines, teeth in upper and lower

jaw The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...

s similar in size,

caudal peduncle Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

with lateral keels; upper precaudal pit usually present, and

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

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, or brain-pan 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 calvaria or sk ...

, 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 branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

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

Species

Currently, 32 recognized species are placed in this genus: * '' Squalus acanthias''

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, t ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoological ...

(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 A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods, cast iron, and ...

, W. T. White & J. D. Stevens, 2007 (eastern highfin spurdog) * '' Squalus altipinnis''

, 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''

, Séret & Pogonoski, 2007 (bighead spurdog) * ''

Squalus chloroculus The greeneye spurdog (''Squalus chloroculus'') is a species of dogfish described in 2007. It is a member of the family Squalidae, found off the coast of southeastern Australia. The length of the longest specimen measured is . It was considered ...

, W. T. White & Motomura, 2007 (greeneye spurdog) * ''

Squalus clarkae ''Squalus clarkae'', also known as Genie's dogfish, is a species of shark from the Gulf of Mexico and western Atlantic. It was described in 2018 and named in honor of ichthyologist Eugenie Clark. It was previously believed to be a part of ''Squa ...

'' Pfleger, Grubbs, Cotton & Daly-Engel, 2018 (Genie's dogfish) * ''

Squalus crassispinus ''Squalus crassispinus'', the fatspine spurdog, is a dogfish of the family Squalidae, found on the continental shelf off the northern coast of Western Australia, at depths of . The length of the longest male specimen measured is . ''Squalus c ...

, M. J. Edmunds &

Yearsley Yearsley is a small village and civil parish in the district of Hambleton in North Yorkshire, England. The population of the civil parish was less than 100 at the 2011 Census. Details are included in the civil parish of Brandsby-cum-Stearsby. ...

, 2007 (fatspine spurdog) * ''

Squalus cubensis The Cuban dogfish (''Squalus cubensis'') is a dogfish, a member of the family Squalidae in the order Squaliformes. Distribution and habitat It is found in the Western Atlantic from North Carolina to Florida, in the Gulf of Mexico, around Cuba, ...

'' Howell-Rivero, 1936 (Cuban dogfish) * '' Squalus edmundsi'' W. T. White,

& J. D. Stevens, 2007 (Edmund's spurdog) * '' Squalus formosus'' W. T. White & Iglésias, 2011 (Taiwan spurdog) * ''

Squalus grahami ''Squalus grahami'', the eastern longnose spurdog, is a dogfish of the family Squalidae Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it ...

'' W. T. White,

& J. D. Stevens, 2007 (eastern longnose spurdog) * '' Squalus griffini'' Phillipps, 1931 (northern spiny dogfish) * ''

Squalus hawaiiensis ''Squalus hawaiiensis'', the Hawaiian spurdog, is a dogfish, a member of the family Squalidae, found in waters surrounding the Hawaiian Islands, from the surface to 950 m. Its length is up to 75 cm. Taxonomy ''Squalus hawaiiensis'' was o ...

'' Daly-Engel,

Koch Koch may refer to: People * Koch (surname), people with this surname * Koch dynasty, a dynasty in Assam and Bengal, north east India * Koch family * Koch people (or Koche), an ethnic group originally from the ancient Koch kingdom in north east ...

, Anderson,

Cotton Cotton 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 cellulose, and can contain minor p ...

, Grubbs, 2018 (Hawaiian spurdog) * '' Squalus hemipinnis'' W. T. White,

, 2007 (Indonesian shortsnout spurdog) * '' Squalus japonicus'' Ishikawa, 1908 (Japanese spurdog) * ''

Squalus lalannei The Seychelles spurdog (''Squalus lalannei'') is a dogfish described in 2003. It is a member of the family Squalidae Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized ...

'' Baranes, 2003 (Seychelles spurdog) * ''

Squalus lobularis The Atlantic lobefin dogfish (''Squalus lobularis'') is a dogfish described in 2016. It is a member of the family Squalidae Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks cate ...

'' Viana, M. R. de Carvalho & U. L. Gomes, 2016 (Atlantic lobefin dogfish) * '' Squalus megalops'' ( W. J. Macleay, 1881) (shortnose spurdog) * ''

Squalus melanurus The blacktailed spurdog (''Squalus melanurus'') is a dogfish, a member of the family Squalidae, found around New Caledonia in the central Pacific Ocean, at depths from 320 to 320 m. Its length is up to 75 cm. Its reproduction is o ...

'' Fourmanoir & Rivaton, 1979 (blacktailed spurdog) * ''

Squalus mitsukurii The shortspine spurdog (''Squalus mitsukurii'') is a dogfish, a member of the family Squalidae, found on continental shelves off Japan in temperate waters, from the surface to 950 m. Its length is up to 75 cm. Taxonomy The shortspine dogf ...

'' D. S. Jordan & Snyder, 1903 (shortspine spurdog) * ''

Squalus montalbani ''Squalus montalbani'', the Philippine spurdog or Indonesian greeneye spurdog, is a relatively large species of dogfish shark native to waters off the coast of Australia, the Philippines, and Indonesia. The species was identified in 1912 from ...

'' Whitley, 1931 (Indonesian greeneye spurdog) * ''

Squalus nasutus '' Squalus nasutus'', the western longnose spurdog, is a dogfish of the family Squalidae, found on the continental shelf off the northwest and southwest coasts of Western Australia, at depths between 300 and 510 m. Its length is at least 55&n ...

, L. J. Marshall & W. T. White, 2007 (western longnose spurdog) * '' Squalus notocaudatus''

, 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 The Cyrano spurdog (''Squalus rancureli'') is a dogfish, a member of the family Squalidae Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making i ...

'' Fourmanoir & Rivaton, 1979 (Cyrano spurdog) * '' Squalus raoulensis'' Duffy &

, 2007 (Kermadec spiny dogfish) *''

Squalus shiraii ''Squalus'' is a genus of dogfish sharks in the family Squalidae. Commonly known as spurdogs, these sharks are characterized by smooth dorsal fin spines, teeth in upper and lower jaws similar in size, caudal peduncle with lateral keels; up ...

'' Viana & M. R. de Carvalho, 2020 (Shirai's spurdog) * ''

Squalus suckleyi The Pacific spiny dogfish (''Squalus suckleyi'') is a common species of the Squalidae (dogfish) family of sharks and are among the most abundant species of sharks in the world. This species is closely related to ''Squalus acanthias'' and for many ...

'' ( Girard, 1855) (Pacific spiny dogfish) Image:Spiny dogfish.jpg, '' Squalus acanthias'' Image:Squalus altipinnis.jpg, '' Squalus altipinnis'' Image:Squalus blainville.jpg, '' Squalus blainville'' Image:Squalus bucephalus JNC2621 Body.JPG, '' Squalus bucephalus'' Image:Squalus chloroculus.jpg, ''

'' Image:Squalus crassispinus.jpg, ''

'' Image:Squalus cubensis eits.jpg, ''

'' Image:Squalus megalops.jpg, '' Squalus megalops'' Image:Squalus melanurus JNC2719 Body.JPG, ''

'' Image:HutoTZ.jpg, ''

References

{{Taxonbar, from=Q737224 Extant Campanian first appearances Taxa named by Carl Linnaeus

Species

See also

References