Fish Codexery

Chondrichthyes

Last updated

Chondrichthyes

Prehistoricplanes · via Wikipedia: Chondrichthyes · CC BY-SA 4.0

Chondrichthyes are jawed vertebrates with a cartilaginous skeleton.[1] The class includes sharks, rays, skates, sawfish, and chimaeras.[2] The smallest living chondrichthyan is the finless sleeper ray at 10 cm, while the largest is the whale shark exceeding 10 m in length.[2]

Scientific classification

  1. KingdomAnimalia
  2. PhylumChordata
  3. ClassChondrichthyes

Named by Huxley, 1880

Sources: Wikipedia taxobox: Chondrichthyes (CC BY-SA 4.0)

Quick Facts

Size range
10 cm (3.94 in) to over 10 m / 32 ft 10 in

Facts from the source article.

Biology and range

Pelagic species must keep swimming to oxygenate their gills, while demersal species can pump water through spiracles.[3] They have electroreceptors called ampullae of Lorenzini that sense electric fields.[4] Most species have large eyes, powerful nostrils, and three semicircular canals in the inner ear.[4] A cartilaginous skeleton is present, and in most species the notochord gets progressively replaced by vertebrae as the animal matures, though Holocephali retain the notochord throughout life.[1]

Certain sharks living in deep water exhibit a diminished vertebral column.[1] Locomotion in the majority of sharks is assisted by a tail with a heterocercal shape.[5] Every member of Chondrichthyes uses five to seven gill pairs for respiration.[3] The nervous system comprises a compact brain, between eight and ten cranial nerve pairs, and a nerve cord running along the spine.[6]

Motion, vibrations, and water pressure are detected by the lateral line system.[4] Acanthodians are thought to be the ancestral group from which cartilaginous fishes arose.[7]

What the specialist sources record

Myelin structure in chondrichthyans is nearly identical to that of tetrapods.[4] Capture-induced parturition occurs in at least 12% of live-bearing sharks and rays.[9] The earliest unequivocal fossils of acanthodian-grade cartilaginous fishes are from the early Silurian, around 439 million years ago.[10] The notochord persists in Holocephali while in other groups it is replaced by a vertebral column.[8][1]

References

  1. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Compagno, "Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date", Food & Agriculture Org., 20 November 2001 (we also read that source) en.wikipedia.org
  2. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: "Chondrichthyan Definition, Species, & Facts Britannica", www.britannica.com (original not read by us) en.wikipedia.org
  3. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Long, "Chondrichthyan/Form and function", Britannica, September 8, 1998 (original not read by us) en.wikipedia.org
  4. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: de Bellard, "Myelin in cartilaginous fish", Brain Research, 2016-06-15, p. 34–42 (original not read by us) en.wikipedia.org
  5. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Wilga, "Function of the heterocercal tail in sharks: quantitative wake dynamics during steady horizontal swimming and vertical maneuvering", Journal of Experimental Biology, 2002, p. 2365–2374 (original not read by us) en.wikipedia.org
  6. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Collin, "The Neuroecology of Cartilaginous Fishes: Sensory Strategies for Survival", Brain, Behavior and Evolution, 2012, p. 80–96 (original not read by us) en.wikipedia.org
  7. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: "A Silurian placoderm with osteichthyan-like marginal jaw bones", Nature, 2013, p. 188–193; Burrow, "The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland", Palaeontologia Electronica, 2016; Maisey, "Pectoral Morphology in Doliodus: Bridging the 'Acanthodian'-Chondrichthyan Divide", American Museum Novitates, 2017, p. 1–15 (original not read by us) en.wikipedia.org
  8. Open Library record, ISBN 9789251045435 ("Sharks of the world"). CC0 (metadata); book content not read. openlibrary.org
  9. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Adams, "Sharks, rays and abortion: The prevalence of capture-induced parturition in elasmobranchs", Biological Conservation, January 2018, p. 11–27; Adams, "Sharks, rays and abortion: The prevalence of capture-induced parturition in elasmobranchs", Biological Conservation, January 2018, p. 11–27 (original not read by us) en.wikipedia.org
  10. Wikipedia, "Chondrichthyes" (CC BY-SA 4.0), which cites: Andreev, "Spiny chondrichthyan from the lower Silurian of South China", Nature, September 2022, p. 969–974; Andreev, "The oldest gnathostome teeth", Nature, 2022-09-28, p. 964–968; Zhu, "The oldest complete jawed vertebrates from the early Silurian of China", Nature, 2022, p. 954–958 (original not read by us) en.wikipedia.org

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Chondrichthyes (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

More in Fish

CoelacanthCypriniformesGalaxiidaeGrouperHaddockHagfishLungfishMahi-mahiMullet (fish)AcanthodiiActinopterygiiAlaska pollock

Sources

Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

Spotted an error? Know more?

Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced

Comments

Loading…
Open in the interactive codex →