Teleost

Teleost
Temporal range: Triassic – Recent
Retroculus (Cichlidae); Hairy Blenny, Labrisomus; Ogcocephalus and Acanthurus
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Infraclass: Teleosteomorpha
Division: Teleostei

Teleosts are the dominant fish of the present day. They arose in the Mesozoic era, and include 20,000 living species. The oldest teleost fossils date back to the late Triassic. They evolved from fish like bowfins in the clade Holostei. During the Mesozoic and Cainozoic they diversified. 96 percent of all known fish species are teleosts.

They are, in order of evolution, vertebrates, jawed fish (Gnathostomata), bony fish (Osteichthyes) and ray-finned fish (Actinopterygii).

Advantages

To account for their success, teleosts must have advantages over earlier fish. In general, teleosts tend to be quicker and more flexible than earlier bony fishes. Their skeletal structure has evolved towards greater lightness. Teleost bones are constructed from a scaffolding of struts, which makes them strong without adding weight.

Teleosts have a movable jaw and changes in the jaw muscles. These changes make it possible for them to protrude their jaws outwards from the mouth. This adaptation improves their ability to grab fast-moving prey.

Date of origin

The date of origin of the teleosts is a difficult problem. Two kinds of evidence are available. There is evidence from the fossil record that the first teleost comes from the late Triassic period.

This date is somewhat later than molecular divergence time estimates (molecular clock). A recent paper finds that fossil dates and molecular clock dates are similar to each other. These researchers state:

"Divergence times estimated from relaxed-molecular clock analyses yield a comprehensive time-scale of actinopterygian diversification that is remarkably close to ages inferred from the fossil record".
Osteichthyes
Actinopterygii 400 mya

part of Chondrostei. So the former "Chondrostei" is paraphyletic (not a clade), and has been broken up by more recent studies. Polypteridae (bichirs)

part of Chondrostei:

Acipenseriformes (sturgeons, paddlefish)

Neopterygii 360 mya

Holostei (bowfins, gars) 275 mya

Teleostei 210 mya

Sarcopterygii
Evolution of ray-finned fish

Teleost superorders

Teleostei

References

  1. ↑ "FishBase". 2006.
  2. ↑ Nelson, Joseph S. 2006. Fishes of the world. Wiley, N.Y. ISBN 0471250317.
  3. ↑ Helfman G. Collette B. & Facey D. 1997. The diversity of fishes. Blackwell, Oxford. ISBN 0-86542-256-7
  4. ↑ Ben Waggoner (1995-07-17). "Telostei". Museum of Paleontology, University of California, Berkeley. Retrieved 2006-06-08.
  5. ↑ Video of a slingjaw wrasse catching prey by protruding its jaw
  6. ↑ Video of a red bay snook catching prey by suction feeding
  7. ↑ Kemp T.S. 1999. Fossils and evolution. Oxford University Press. p122 ISBN 0198504241
  8. ↑ Palmer D. (ed) 1999. The Marshall illustrated encyclopedia of dinosaurs and prehistoric animals. London: Marshall Editions. p38 ISBN 1-84028-152-9
  9. 1 2 3 Near, Thomas J. et al. 2012. Resolution of ray-finned fish phylogeny and timing of diversification. PNAS (Proceedings of the National Academy of Sciences of the United States of America). pp. 13698–13703. Archived 2018-04-30 at the Wayback Machine
  10. ↑ Betancur-R, Ricardo; et al. (2013). "The Tree of Life and a new classification of bony fishes". PLOS Currents Tree of Life. 5 (1st ed.). doi:10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288. hdl:2027.42/150563. PMC 3644299. PMID 23653398.