Encyclopedia > Actinopterygii

  Article Content


Ray-finned fish
(image here)
Scientific classification

The Actinopterygii are the ray-finned fish. They are the dominant group of vertebrates, with over 27,000 species ubiquitous throughout freshwater and marine environments. They are traditionally treated as a subclass of the Osteichthyes, or bony fish, but as that group is paraphyletic they may be treated as a full class.

Traditionally three grades of Actinopterygii have been recognized: the Chondrostei, Holostei, and Teleostei. The second is paraphyletic and tends to be abandoned, however, while the first is now restricted to those forms closer to extant Chondrostei than to the other groups. Nearly all fish alive today are teleosts. A listing of the different groups is given below, down to the level of orders, arranged in what is believed to represent the evolutionary sequence down to the level of superorder.

External link

  • NCBI Taxonomy entry (http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?name=actinopterygii)

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article

... of flying individuals are dark, but termites which remain in the nest are whitish with only their heads being heavily pigmented. The temporary wings of termites are long and ...