Editing Teleost (section)

{{Short description|Division or infraclass of fishes}}
{{Featured article}}
{{Use dmy dates|date=May 2016}}
{{Automatic taxobox
| fossil_range      = {{Fossil range|Early Triassic|Recent|ref=<ref name=Palmer>{{cite book |last=Palmer |first=Douglas |title=The Marshall Illustrated Encyclopedia of Dinosaurs & Prehistoric Animals |publisher=Marshall Editions Developments |year=1999 |isbn=978-1-84028-152-1}}</ref><ref>{{cite web |title=The Paleobiology Database |publisher=The Paleobiology Database |date=14 June 2013 |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=202677 |access-date=14 June 2013 |archive-date=27 March 2020 |archive-url=https://web.archive.org/web/20200327181728/http://paleodb.org/?a=basicTaxonInfo&taxon_no=202677 |url-status=live }}</ref>}}
| image             = F de Castelnau-poissons - Diversity of Fishes (Composite Image).jpg
| image_upright     = 1.3
| image_caption     = Teleosts of different orders, painted by [[François-Louis Laporte, comte de Castelnau|Castelnau]], 1856 (left to right, top to bottom): <!--Plate 9: "Aulastoma margravii"=-->''[[Fistularia tabacaria]]'' ([[Syngnathiformes]]), <!--Plate 34: "Myletes duriventris"=-->''[[Mylossoma duriventre]]'' ([[Characiformes]]), <!--Plate 9: "Chromys ?acora"=-->''[[Mesonauta acora]]'' ([[Cichliformes]]), <!--Plate 18: "Callichthys splendens"=-->''[[Corydoras splendens]]'' and <!--Plate 22: "Hypostomus spinosus"=-->''[[Pseudacanthicus spinosus]]'' ([[Siluriformes]]), <!--Plate 12: "Acanthurus coeruleus"=-->''[[Acanthurus coeruleus]]'' ([[Acanthuriformes]]), <!--Plate 2: "Pomacanthus pictus"=-->''[[Stegastes pictus]]'' ([[Blenniiformes]])
| taxon             = Teleostei
| authority         = [[Johannes Peter Müller|J. P. Müller]], 1845<ref>{{cite journal |last=Müller |first=Johannes |title=Über den Bau und die Grenzen der Ganoiden, und über das natürliche System der Fische |journal=Archiv für Naturgeschichte |date=1845 |volume=11 |issue=1 |page=129 |url=https://www.biodiversitylibrary.org/page/6483059}}</ref>
| subdivision_ranks = Subgroups<!--Superorders: disputable-->
| subdivision       = See text
}}

'''Teleostei''' ({{IPAc-en|ˌ|t|ɛ|l|i|ˈ|ɒ|s|t|i|aɪ}}; [[Ancient Greek|Greek]] ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as '''teleosts''' ({{IPAc-en|ˈ|t|ɛ|l|i|ɒ|s|t|s|,_|ˈ|t|iː|l|i|-}}),<ref>{{cite Dictionary.com|teleost}}</ref> is, by far, the largest group of ray-finned fishes (class [[Actinopterygii]]),{{efn|The other three groups are the [[Holostei]] ([[bowfin]]s and [[gar]]s), the [[Chondrostei]] ([[sturgeon]]s and [[paddlefish]]), and the [[Cladistia]] ([[bichir]]s and [[reedfish]]).}} with 96% of all [[neontology|extant]] species of [[fish]]. The Teleostei, which is variously considered a [[Division (zoology)|division]] or an [[infraclass]] in different taxonomic systems, include over 26,000 [[species]] that are arranged in about 40 [[order (biology)|orders]] and 448 [[family (biology)|families]]. Teleosts range from [[giant oarfish]] measuring {{convert|7.6|m|ft|0|abbr=on}} or more, and [[ocean sunfish]] weighing over {{convert|2|t|ton|1|abbr=on}}, to the minute male [[anglerfish]] ''[[Photocorynus spiniceps]]'', just {{convert|6.2|mm|in|2|abbr=on}} long. Including not only torpedo-shaped fish built for speed, teleosts can be flattened vertically or horizontally, be elongated cylinders or take specialised shapes as in anglerfish and [[seahorse]]s.

The difference between teleosts and other bony fish lies mainly in their jaw bones; teleosts have a movable [[premaxilla]] and corresponding modifications in the jaw musculature which make it possible for them to [[cranial kinesis|protrude their jaws outwards from the mouth]]. This is of great advantage, enabling them to [[predation|grab prey]] and [[suction feeding|draw it into the mouth]]. In more [[synapomorphy|derived]] teleosts, the enlarged premaxilla is the main tooth-bearing bone, and the maxilla, which is attached to the lower jaw, acts as a lever, pushing and pulling the premaxilla as the mouth is opened and closed. Other bones further back in the mouth serve to grind and swallow food. Another difference is that the upper and lower lobes of the [[fish anatomy|tail (caudal) fin]] are about equal in size. The [[vertebral column|spine]] ends at the [[caudal peduncle]], distinguishing this group from other fish in which the spine extends into the upper lobe of the tail fin.

Teleosts have adopted a range of [[fish reproduction|reproductive strategies]]. Most use external fertilisation: the female lays a batch of eggs, the male fertilises them and the [[larva]]e develop without any further parental involvement. A fair proportion of teleosts are sequential [[hermaphrodite]]s, starting life as females and transitioning to males at some stage, with a few species reversing this process. A small percentage of teleosts are [[viviparity|viviparous]] and some provide parental care with typically the male fish guarding a nest and fanning the eggs to keep them well-oxygenated.

Teleosts are economically important to humans, as is shown by their [[Fish in culture#In art|depiction in art]] over the centuries. The [[commercial fishing|fishing industry]] harvests them for food, and [[angling|anglers]] attempt to capture them [[recreational fishing|for sport]]. Some species are [[fish farming|farmed]] commercially, and this method of production is likely to be increasingly important in the future. Others are kept in [[aquarium]]s or used in research, especially in the fields of [[genetics]] and [[developmental biology]].