Spurdog

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; 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, 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.[2]

Spurdogs
Temporal range: 83–0 Ma Campanian to Present[1]
Spiny dogfish (Squalus acanthias)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Squaliformes
Family: Squalidae
Genus: Squalus
Linnaeus, 1758

The name comes from squalus, the Latin 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.

Species

Currently, 30 recognized species are placed in this genus:

See also

References

  1. Sepkoski, J.J.Jr (2002). "A Compendium of Fossil Marine Animal Genera". Bulletins of American Paleontology. 363: 1–560.
  2. 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.
  3. 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.
  4. Viana, Sarah T. F. L.; Carvalho, Marcelo R. de (2020-10-06). "Squalus shiraii sp. nov. (Squaliformes, Squalidae), a new species of dogfish shark from Japan with regional nominal species revisited". Zoosystematics and Evolution. 96(2): 275–311. doi:10.3897/zse.96.51962. ISSN 1860-0743.
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