actinopterygii

File:Anatomia dei pesci.jpg)}}

A: dorsal fin, B: fin rays, C: lateral line, D: kidney, E: swim bladder, F: Weberian apparatus, G: inner ear, H: brain, I: nostrils, L: eye, M: gills, N: heart, O: stomach, P: gall bladder, Q: spleen, R: internal sex organs (ovaries or testes), S: ventral fins, T: spine, U: anal fin, V: tail (caudal fin). Possible other parts not shown: barbels, adipose fin, external genitalia (gonopodium)]]

Ray-finned fishes occur in many variant forms. The main features of typical ray-finned fish are shown in the adjacent diagram.

The swim bladder is a more derived structure and used for buoyancy.{{cite journal |last1=Funk |first1=Emily |last2=Breen |first2=Catriona |last3=Sanketi |first3=Bhargav |last4=Kurpios |first4=Natasza |last5=McCune |first5=Amy |author5-link=Amy McCune |title=Changing in Nkx2.1, Sox2, Bmp4, and Bmp16 expression underlying the lung-to-gas bladder evolutionary transition in ray-finned fishes |journal=Evolution & Development |date=2020 |volume=22 |issue=5 |pages=384–402|doi=10.1111/ede.12354 |pmid=33463017 |pmc=8013215 }} Except from the bichirs, which just like the lungs of lobe-finned fish have retained the ancestral condition of ventral budding from the foregut, the swim bladder in ray-finned fishes derives from a dorsal bud above the foregut.{{Cite journal|title=Changes in Nkx2.1, Sox2, Bmp4, and Bmp16 expression underlying the lung-to-gas bladder evolutionary transition in ray-finned fishes|first1=Emily C.|last1=Funk|first2=Catriona|last2=Breen|first3=Bhargav D.|last3=Sanketi|first4=Natasza|last4=Kurpios|first5=Amy|last5=McCune|author5-link=Amy McCune|date=25 September 2020|journal=Evolution & Development|volume=22|issue=5|pages=384–402|doi=10.1111/ede.12354|pmid=33463017|pmc=8013215}} In early forms the swim bladder could still be used for breathing, a trait still present in Holostei (bowfins and gars).{{Cite journal|title=A single-cell atlas of West African lungfish respiratory system reveals evolutionary adaptations to terrestrialization|first1=Ruihua|last1=Zhang|first2=Qun|last2=Liu|first3=Shanshan|last3=Pan|first4=Yingying|last4=Zhang|first5=Yating|last5=Qin|first6=Xiao|last6=Du|first7=Zengbao|last7=Yuan|first8=Yongrui|last8=Lu|first9=Yue|last9=Song|first10=Mengqi|last10=Zhang|first11=Nannan|last11=Zhang|first12=Jie|last12=Ma|first13=Zhe|last13=Zhang|first14=Xiaodong|last14=Jia|first15=Kun|last15=Wang|first16=Shunping|last16=He|first17=Shanshan|last17=Liu|first18=Ming|last18=Ni|first19=Xin|last19=Liu|first20=Xun|last20=Xu|first21=Huanming|last21=Yang|first22=Jian|last22=Wang|first23=Inge|last23=Seim|first24=Guangyi|last24=Fan|date=13 September 2023|journal=Nature Communications|volume=14|issue=1|pages=5630|doi=10.1038/s41467-023-41309-3|pmid=37699889 |pmc=10497629 |bibcode=2023NatCo..14.5630Z }} In some fish like the arapaima, the swim bladder has been modified for breathing air again,{{Cite journal|title=Morphology of the Amazonian Teleost Genus Arapaima Using Advanced 3D Imaging|first1=Miriam|last1=Scadeng|first2=Christina|last2=McKenzie|first3=Weston|last3=He|first4=Hauke|last4=Bartsch|first5=David J.|last5=Dubowitz|first6=Dominik|last6=Stec|first7=Judy|last7=St. Leger|date=25 November 2020|journal=Frontiers in Physiology|volume=11|page=260 |doi=10.3389/fphys.2020.00260 |pmid=32395105 |pmc=7197331 |doi-access=free }} and in other lineages it has been completely lost.{{Cite journal|title=Bone Density Variation in Rattails (Macrouridae, Gadiformes): Buoyancy, Depth, Body Size, and Feeding|first1=Rene P|last1=Martin|first2=Abigail S|last2=Dias|first3=Adam P|last3=Summers|first4=Mackenzie E|last4=Gerringer|date=16 October 2022|journal=Integrative Organismal Biology|volume=4|issue=1|pages=obac044|doi=10.1093/iob/obac044|pmid=36381998|pmc=9652093}}

The teleosts have urinary and reproductive tracts that are fully separated, while the Chondrostei have common urogenital ducts, and partially connected ducts are found in Cladistia and Holostei.[https://www.nature.com/articles/s41598-023-46900-8 Post-testicular sperm maturation in ancient holostean species]

Ray-finned fishes have many different types of scales; but all teleosts have leptoid scales. The outer part of these scales fan out with bony ridges, while the inner part is crossed with fibrous connective tissue. Leptoid scales are thinner and more transparent than other types of scales, and lack the hardened enamel- or dentine-like layers found in the scales of many other fish. Unlike ganoid scales, which are found in non-teleost actinopterygians, new scales are added in concentric layers as the fish grows.{{Cite web|title=Actinopterygii Klein, 1885|url=https://www.gbif.org/species/113225725|access-date=2021-09-20|website=www.gbif.org|language=en}}

Teleosts and chondrosteans (sturgeons and paddlefish) also differ from the bichirs and holosteans (bowfin and gars) in having gone through a whole-genome duplication (paleopolyploidy). The WGD is estimated to have happened about 320 million years ago in the teleosts, which on average has retained about 17% of the gene duplicates, and around 180 (124–225) million years ago in the chondrosteans. It has since happened again in some teleost lineages, like Salmonidae (80–100 million years ago) and several times independently within the Cyprinidae (in goldfish and common carp as recently as 14 million years ago).{{Cite journal|title=Fossilized cell structures identify an ancient origin for the teleost whole-genome duplication|first1=Donald|last1=Davesne|first2=Matt|last2=Friedman|first3=Armin D.|last3=Schmitt|first4=Vincent|last4=Fernandez|first5=Giorgio|last5=Carnevale|first6=Per E.|last6=Ahlberg|first7=Sophie|last7=Sanchez|first8=Roger B. J.|last8=Benson|date=27 July 2021|journal=Proceedings of the National Academy of Sciences|volume=118|issue=30|doi=10.1073/pnas.2101780118|pmid=34301898|pmc=8325350 |bibcode=2021PNAS..11801780D |doi-access=free }}{{Cite journal|url=https://genome.cshlp.org/content/early/2022/08/12/gr.276953.122|title=An atlas of fish genome evolution reveals delayed rediploidization following the teleost whole-genome duplication|first1=Elise|last1=Parey|first2=Alexandra|last2=Louis|first3=Jerome|last3=Montfort|first4=Yann|last4=Guiguen|first5=Hugues Roest|last5=Crollius|first6=Camille|last6=Berthelot|date=12 August 2022|journal=Genome Research|volume=32 |issue=9 |pages=1685–1697|via=genome.cshlp.org|doi=10.1101/gr.276953.122|pmid=35961774|pmc=9528989 }}{{Cite journal |last1=Du |first1=Kang |last2=Stöck |first2=Matthias |last3=Kneitz |first3=Susanne |last4=Klopp |first4=Christophe |last5=Woltering |first5=Joost M. |last6=Adolfi |first6=Mateus Contar |last7=Feron |first7=Romain |last8=Prokopov |first8=Dmitry |last9=Makunin |first9=Alexey |last10=Kichigin |first10=Ilya |last11=Schmidt |first11=Cornelia |last12=Fischer |first12=Petra |last13=Kuhl |first13=Heiner |last14=Wuertz |first14=Sven |last15=Gessner |first15=Jörn |date=2020 |title=The sterlet sturgeon genome sequence and the mechanisms of segmental rediploidization |journal=Nature Ecology & Evolution |language=en |volume=4 |issue=6 |pages=841–852 |doi=10.1038/s41559-020-1166-x |pmid=32231327 |bibcode=2020NatEE...4..841D |issn=2397-334X|pmc=7269910 }}{{Cite journal |last1=Kuraku |first1=Shigehiro |last2=Sato |first2=Mana |last3=Yoshida |first3=Kohta |last4=Uno |first4=Yoshinobu |date=2024 |title=Genomic reconsideration of fish non-monophyly: why cannot we simply call them all 'fish'? |journal=Ichthyological Research |language=en |volume=71 |issue=1 |pages=1–12 |doi=10.1007/s10228-023-00939-9 |bibcode=2024IchtR..71....1K |issn=1616-3915|doi-access=free }}{{Cite journal |last1=Xu |first1=Peng |last2=Xu |first2=Jian |last3=Liu |first3=Guangjian |last4=Chen |first4=Lin |last5=Zhou |first5=Zhixiong |last6=Peng |first6=Wenzhu |last7=Jiang |first7=Yanliang |last8=Zhao |first8=Zixia |last9=Jia |first9=Zhiying |last10=Sun |first10=Yonghua |last11=Wu |first11=Yidi |last12=Chen |first12=Baohua |last13=Pu |first13=Fei |last14=Feng |first14=Jianxin |last15=Luo |first15=Jing |date=2019 |title=The allotetraploid origin and asymmetrical genome evolution of the common carp Cyprinus carpio |journal=Nature Communications |language=en |volume=10 |issue=1 |pages=4625 |doi=10.1038/s41467-019-12644-1 |pmid=31604932 |bibcode=2019NatCo..10.4625X |issn=2041-1723|pmc=6789147 }}

{{clear-left}}

{{Further|Fish fin|Diversity of fish}}

Ray-finned fish vary in size and shape, in their feeding specializations, and in the number and arrangement of their ray-fins.

{{gallery

| height=100px

| mode=nolines

| noborder=true

|File:Bluefin-big.jpg|Tuna are streamlined for straight line speed with a deeply forked tail

|File:Swordfish (Duane Raver).png|The swordfish is even faster and more streamlined than the tuna

|File:Salmo salar.jpg|Salmon generate enough thrust with their tail fin to jump obstacles during river migrations

|File:Atlantic cod.jpg|Cod have three dorsal and two anal fins, which give them great maneuverability

|File:Ancylopsetta dilecta 2.jpg|Flatfish have developed partially symmetric dorsal and pelvic fins

|File:Anableps anableps2.jpg|The four-eyed fish Anableps anableps can see both below and above the water surface

|File:Diaphus metopoclampus.jpg|Lanternfish

|File:Gonostoma elongatum.jpg|Elongated bristlemouth

|File:Anoplogaster cornuta 2.jpg|Fangtooth are indifferent swimmers who try to ambush their prey

|File:Melanocetus johnsonii.jpg|The first spine of the dorsal fin of anglerfish is modified like a fishing rod with a lure

|File:Beryx decadactylus.jpg|Alfonsino

|File:Polypterus bichir (cropped).jpg|Bichirs and their relatives in the order Polypteriformes are sister to all other extant ray-fins; they possess lungs

|File:King of herrings.png|Giant oarfish

|File:Conger conger Gervais.jpg|European conger are ray-finned fish

|File:FMIB 42560 Pterois sphex Jordan & Evermann; from the type 2.jpeg|Hawaiian turkeyfish

|File:Ogcocephalus notatus Castelnau.jpg|The benthic batfish Ogcocephalus notatus

|File:Saccopharynx.JPG|The deep sea eel Saccopharynx ampullaceus

|File:Campylomormyrus curvirostris (Boulenger, 1898).jpg|The freshwater elephant fish Campylomormyrus curvirostris

|File:Acipenser oxyrhynchus (edit).png|The sturgeon Acipenser oxyrhynchus has a cartilaginous endoskeleton

|File:Belone belone1.jpg|The ambush predator needlefish Belone belone

|File:Seahorse-col.svg|Seahorses are in the extended pipefish family

|File:Mirror dory.png|Mirror dory

|File:Coryphaena hippurus.png|Mahi-mahi

|File:Exocoetus obtusirostris.jpg|The "flying fish" Exocoetus obtusirostris has specialized pectoral fins for gliding

|File:Momol u0.gif|The hoodwinker sunfish Mola tecta has no caudal fin

|File:Leedsichthys problematicus.jpg|The Jurassic {{extinct}}Leedsichthys was a filter-feeder and the largest ray-finned fish to have ever lived

|File:Lactoria fornasini1.jpg|Lactoria fornasini is a poisonous species of boxfish

|File:Lepisosteus platostomus drawing.jpg|Gars (along with the bowfin) are the only surviving members of the Holostei

}}

File:Gasterosteus aculeatus 1879.jpg (Gasterosteus aculeatus) males (red belly) build nests and compete to attract females to lay eggs in them. Males then defend and fan the eggs. Painting by Alexander Francis Lydon, 1879]]

In nearly all ray-finned fish, the sexes are separate, and in most species the females spawn eggs that are fertilized externally, typically with the male inseminating the eggs after they are laid. Development then proceeds with a free-swimming larval stage.{{cite book |title=Zoology |url=https://archive.org/details/zoology0000dori |url-access=registration |last1=Dorit |first1=R.L. |last2=Walker |first2=W.F. |last3=Barnes |first3=R.D. |year=1991 |publisher=Saunders College Publishing |isbn=978-0-03-030504-7 |page=[https://archive.org/details/zoology0000dori/page/819 819] }} However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism. In most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. Protandry, where a fish converts from male to female, is much less common than protogyny.{{cite journal |title=Evolutionary perspectives on hermaphroditism in fishes |journal=Sexual Development |year=2009 |first=J.C. |last=Avise |author-link=John Avise |author2=Mank, J.E. |volume=3 |issue=2–3 |pages=152–163|doi=10.1159/000223079|pmid=19684459 |s2cid=22712745 |url=https://escholarship.org/uc/item/1px4b8qn }}

Most families use external rather than internal fertilization.{{cite book|last=Pitcher|first=T|title=The Behavior of Teleost Fishes|year=1993|publisher=Chapman & Hall|location=London}} Of the oviparous teleosts, most (79%) do not provide parental care.{{cite journal |last=Reynolds |first=John|author2=Nicholas B. Goodwin |author3=Robert P. Freckleton |title=Evolutionary Transitions in Parental Care and Live Bearing in Vertebrates |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |date=19 March 2002 |volume=357 |issue=1419 |pmc=1692951 |pmid=11958696 |doi=10.1098/rstb.2001.0930 |pages=269–281}} Viviparity, ovoviviparity, or some form of parental care for eggs, whether by the male, the female, or both parents is seen in a significant fraction (21%) of the 422 teleost families; no care is likely the ancestral condition. The oldest case of viviparity in ray-finned fish is found in Middle Triassic species of {{extinct}}Saurichthys.{{cite journal | author = Maxwell | display-authors = etal | year = 2018 | title = Re-evaluation of the ontogeny and reproductive biology of the Triassic fish Saurichthys (Actinopterygii, Saurichthyidae) | journal = Palaeontology | volume = 61 | pages = 559–574 | doi = 10.5061/dryad.vc8h5 }} Viviparity is relatively rare and is found in about 6% of living teleost species; male care is far more common than female care.{{cite book|last=Clutton-Brock|first=T. H.|author-link=Tim Clutton-Brock|title=The Evolution of Parental Care|year=1991|publisher=Princeton UP|location=Princeton, NJ}} Male territoriality "preadapts" a species for evolving male parental care.{{cite journal |last=Werren |first=John|author2=Mart R. Gross |author3=Richard Shine |author3-link=Richard Shine |title=Paternity and the evolution of male parentage |journal=Journal of Theoretical Biology |year=1980 |volume=82|issue=4 |doi=10.1016/0022-5193(80)90182-4 |pmid=7382520|url=https://www.researchgate.net/publication/222458526 |access-date=15 September 2013 |pages=619–631}}{{cite journal |last=Baylis |first=Jeffrey |title=The Evolution of Parental Care in Fishes, with reference to Darwin's rule of male sexual selection |journal=Environmental Biology of Fishes |year=1981 |volume=6 |issue=2 |doi=10.1007/BF00002788 |pages=223–251|bibcode=1981EnvBF...6..223B |s2cid=19242013 }}

There are a few examples of fish that self-fertilise. The mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the fish's habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below {{convert|19|°C}} and can fertilise eggs that are then spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred.{{cite book|author1=Wootton, Robert J.|author2=Smith, Carl|title=Reproductive Biology of Teleost Fishes|url=https://books.google.com/books?id=_YnjBAAAQBAJ|year=2014|publisher=Wiley |isbn=978-1-118-89139-1}}

{{clear}}

File:Evolution of ray-finned fish.png

{{See also|Evolution of fish}}

Actinopterygii is divided into the subclasses Cladistia, Chondrostei and Neopterygii. The Neopterygii, in turn, is divided into the infraclasses Holostei and Teleostei. During the Mesozoic (Triassic, Jurassic, Cretaceous) and Cenozoic the teleosts in particular diversified widely. As a result, 96% of living fish species are teleosts (40% of all fish species belong to the teleost subgroup Acanthomorpha), while all other groups of actinopterygians represent depauperate lineages.{{cite journal |last1=Sallan |first1=Lauren C. |author1-link=Lauren Sallan |title=Major issues in the origins of ray-finned fish (Actinopterygii) biodiversity |journal=Biological Reviews |date=February 2014 |volume=89 |issue=4 |pages=950–971 |doi=10.1111/brv.12086|pmid=24612207 |hdl=2027.42/109271 |s2cid=24876484 |hdl-access=free }}

The classification of ray-finned fishes can be summarized as follows:

• Cladistia, which include bichirs and reedfish
• Actinopteri, which include:
• Chondrostei, which include Acipenseriformes (paddlefishes and sturgeons)
• Neopterygii, which include:
• Teleostei (most living fishes)
• Holostei, which include:
• Lepisosteiformes (gars)
• Amiiformes (bowfin)

The cladogram below shows the main clades of living actinopterygians and their evolutionary relationships to other extant groups of fishes and the four-limbed vertebrates (tetrapods).{{cite journal |title=Resolution of ray-finned fish phylogeny and timing of diversification |author=Thomas J. Near |author-link=Thomas J. Near |journal=PNAS |doi=10.1073/pnas.1206625109 |pmid=22869754 |date=2012 |volume=109 |issue=34 |pages=13698–13703 |display-authors=etal |pmc=3427055 |bibcode=2012PNAS..10913698N|doi-access=free }}{{cite journal|author=Betancur-R, Ricardo |display-authors=etal |year=2013 |title=The Tree of Life and a New Classification of Bony Fishes |journal=PLOS Currents Tree of Life |volume=5 |issue=Edition 1 |doi=10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288 |pmid=23653398 |pmc=3644299 |hdl=2027.42/150563 |doi-access=free }} The latter include mostly terrestrial species but also groups that became secondarily aquatic (e.g. whales and dolphins). Tetrapods evolved from a group of bony fish during the Devonian period.{{cite journal|author1=Laurin, M. |author2=Reisz, R.R. |year=1995 |title=A reevaluation of early amniote phylogeny|journal=Zoological Journal of the Linnean Society|volume=113 |issue=2 |pages=165–223 |doi=10.1111/j.1096-3642.1995.tb00932.x}} Approximate divergence dates for the different actinopterygian clades (in millions of years, mya) are from Near et al., 2012.

{{clade

|label1=Vertebrates

|1={{clade

|1=Jaw-less fishes (hagfish, lampreys) 80px

|label2=Jawed vertebrates

|2={{clade

|1=Cartilaginous fishes (sharks, rays, ratfish) 80px

|label2=Euteleostomi

|sublabel2=('bony fish')

|2={{clade

|label1=Sarcopterygii

|sublabel1=(lobe-fins)

|1={{clade

|label1=Actinistia

|1=Coelacanths 70px

|label2=Rhipidistia

|2={{clade

|1=Lungfish 70 px

|label2=Tetrapods

|2={{clade

|1=Amphibians 70px

|label2=Amniota

|2={{clade

|1=Mammals 60px

|2=Sauropsids (reptiles, birds) 70px

}}

}}

}}

}}

|label2=Actinopterygii

|sublabel2={{small|400 mya}}

|2={{clade

|label1=Cladistia

|1=Polypteriformes (bichirs, reedfishes) 80px

|label2=Actinopteri

|2={{clade

|label1=Chondrostei

|1=Acipenseriformes (sturgeons, paddlefishes) 80px

|label2=Neopterygii |sublabel2={{small|360 mya}}

|2={{clade

|sublabel1={{small|310 mya}}

|1=Teleostei 70px

|label2=Holostei

|sublabel2={{small|275 mya}}

|2={{clade

|1=Amiiformes (bowfins) 70px

|2=Lepisosteiformes (gars) 80px

}}

}}

}}

}}

}}

}}

}}

}}

The polypterids (bichirs and reedfish) are the sister lineage of all other actinopterygians, the Acipenseriformes (sturgeons and paddlefishes) are the sister lineage of Neopterygii, and Holostei (bowfin and gars) are the sister lineage of teleosts. The Elopomorpha (eels and tarpons) appear to be the most basal teleosts.

The earliest known fossil actinopterygian is Andreolepis hedei, dating back 420 million years (Late Silurian), remains of which have been found in Russia, Sweden, and Estonia.{{cite web|url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=34968|title=Fossilworks: Andreolepis|access-date=14 May 2008|archive-url=https://web.archive.org/web/20100212023014/http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=34968&is_real_user=1|archive-date=12 February 2010|url-status=live}} Crown group actinopterygians most likely originated near the Devonian-Carboniferous boundary.{{cite journal |last1=Henderson |first1=Struan |last2=Dunne |first2=Emma M. |last3=Fasey |first3=Sophie A. |last4=Giles |first4=Sam |author4-link=Sam Giles |date=3 October 2022 |title=The early diversification of ray-finned fishes (Actinopterygii): hypotheses, challenges and future prospects |journal=Biological Reviews |volume=98 |issue=1 |pages=284–315 |doi=10.1111/brv.12907 |pmid=36192821 |pmc=10091770 |s2cid=241850484 }} The earliest fossil relatives of modern teleosts are from the Triassic period (Prohalecites, Pholidophorus),{{Cite journal|author1=Arratia, G. |name-list-style=amp |year=2015 |title=Complexities of early teleostei and the evolution of particular morphological structures through time. |journal=Copeia |volume=103 |issue=4 |pages=999–1025 |doi=10.1643/CG-14-184|s2cid=85808890 }}{{cite journal |last1=Romano |first1=Carlo |last2=Koot |first2=Martha B. |last3=Kogan |first3=Ilja |last4=Brayard |first4=Arnaud |last5=Minikh |first5=Alla V. |last6=Brinkmann |first6=Winand |last7=Bucher |first7=Hugo |last8=Kriwet |first8=Jürgen |title=Permian-Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution |journal=Biological Reviews |date=February 2016 |volume=91 |issue=1 |pages=106–147 |doi=10.1111/brv.12161 |pmid=25431138 |s2cid=5332637 |url=https://hal.archives-ouvertes.fr/hal-01253154 }} although it is suspected that teleosts originated already during the Paleozoic Era.

class="wikitable"
Chondrostei |140px{{center|Atlantic sturgeon}} |valign=top |Chondrostei (cartilage bone) is a subclass of primarily cartilaginous fish showing some ossification. Earlier definitions of Chondrostei are now known to be paraphyletic, meaning that this subclass does not contain all the descendants of their common ancestor. There used to be 52 species divided among two orders, the Acipenseriformes (sturgeons and paddlefishes) and the Polypteriformes (reedfishes and bichirs). Reedfish and birchirs are now separated from the Chondrostei into their own sister lineage, the Cladistia. It is thought that the chondrosteans evolved from bony fish but lost the bony hardening of their cartilaginous skeletons, resulting in a lightening of the frame. Elderly chondrosteans show beginnings of ossification of the skeleton, suggesting that this process is delayed rather than lost in these fish.{{cite web|url=http://www.palaeos.com/Vertebrates/Units/090Teleostomi/090.300.html |title=Chondrosteans: Sturgeon Relatives |publisher=paleos.com |url-status=dead |archive-url=https://web.archive.org/web/20101225152809/http://www.palaeos.com/Vertebrates/Units/090Teleostomi/090.300.html |archive-date=25 December 2010}} This group had once been classified with the sharks: the similarities are obvious, as not only do the chondrosteans mostly lack bone, but the structure of the jaw is more akin to that of sharks than other bony fish, and both lack scales (excluding the Polypteriforms). Additional shared features include spiracles and, in sturgeons, a heterocercal tail (the vertebrae extend into the larger lobe of the caudal fin). However the fossil record suggests that these fish have more in common with the Teleostei than their external appearance might suggest.
Neopterygii |140px{{center|Atlantic salmon}} |Neopterygii (new fins) is a subclass of ray-finned fish that appeared somewhere in the Late Permian. There were only few changes during its evolution from the earlier actinopterygians. Neopterygians are a very successful group of fishes because they can move more rapidly than their ancestors. Their scales and skeletons began to lighten during their evolution, and their jaws became more powerful and efficient. While electroreception and the ampullae of Lorenzini is present in all other groups of fish, with the exception of hagfish, neopterygians have lost this sense, though it later re-evolved within Gymnotiformes and catfishes, who possess nonhomologous teleost ampullae.{{cite book|author=Theodore Holmes Bullock|author-link=Theodore Holmes Bullock|author2=Carl D. Hopkins|author3=Arthur N. Popper|title=Electroreception|url=https://books.google.com/books?id=d1-rak1asv0C&pg=PA229|year=2005|publisher=Springer Science+Business Media, Incorporated|isbn=978-0-387-28275-6|page=229 }}

File:Cheirolepis canadensis.jpg {{extinct}}cheirolepidiform {{extinct}}Cheirolepis canadensis]]

File:Elonichthys peltigerus.jpg {{extinct}}elonichthyiform {{extinct}}Elonichthys peltigerus]]

File:Aeduella sp.JPG {{extinct}}aeduelliform {{extinct}}Aeduella blainvillei]]

File:PalaeoniscusFreieslebenensis-NaturalHistoryMuseum-August23-08.jpg {{extinct}}palaeonisciform {{extinct}}Palaeoniscum freieslebeni]]

File:Bobasatrania canadensis 1.jpg {{extinct}}bobasatraniiform {{extinct}}Bobasatrania canadensis]]

File:Italopterus magnificus 01.jpg {{extinct}}perleidiform {{extinct}}Thoracopterus magnificus]]

File:Prohalecites sp Rasa 1.JPG {{extinct}}prohaleciteiform {{extinct}}Prohalecites sp., the earliest teleosteomorph]]

File:Aspidorhynchus sp.jpg {{extinct}}aspidorhynchiform {{extinct}}Aspidorhynchus sp.]]

File:Pachycormus curtus SMNS 55300.jpg {{extinct}}pachycormiform {{extinct}}Pachycormus curtus]]

File:Yanosteus longidorsalis MHNT.jpg acipenseriform {{extinct}}Yanosteus longidorsalis]]

File:Nematonotus longispinus.jpg aulopiform {{extinct}}Nematonotus longispinus]]

File:Thrissops formosus 3.JPG {{extinct}}ichthyodectiform {{extinct}}Thrissops formosus]]

File:Mene oblonga 23.JPG carangiform {{extinct}}Mene oblonga]]

File:Amphistium.JPG pleuronectiform {{extinct}}Amphistium paradoxum]]

File:Priscacara serrata FMNH PF13014 img1.jpg) from the Lower Eocene about 50 million years ago]]

File:Nerophis (7992564775).jpg syngnathiform {{extinct}}Nerophis zapfei]]

File:Lophius piscatorius MHNT.jpg. The first spine of the dorsal fin of the anglerfish is modified so it functions like a fishing rod with a lure]]

File:Lingcodskeleton1600ppx.JPG]]

File:Blue catfish skeleton.jpg skeleton}}]]

The listing below is a summary of all extinct (indicated by a dagger, †) and living groups of Actinopterygii with their respective taxonomic rank. The taxonomy follows Eschmeyer's Catalog of Fishes{{Cite web |last=Fricke |first=R. |last2=Eschmeyer |first2=W. N. |last3=Van der Laan |first3=R. |date=2025 |title=ESCHMEYER'S CATALOG OF FISHES: CLASSIFICATION |url=https://www.calacademy.org/eschmeyers-catalog-of-fishes-classification |access-date=2025-02-10 |website=California Academy of Sciences |language=en}} and Phylogenetic Classification of Bony Fishes with notes when this differs from Nelson, ITIS{{ITIS |id=161061 |taxon=Actinopterygii |access-date=3 April 2006}} and FishBase{{cite web |editor=R. Froese and D. Pauly|title=FishBase |url=http://www.fishbase.org |date=February 2006 |access-date=8 January 2020 |archive-url=https://web.archive.org/web/20180705004623/http://www.fishbase.org/Summary/FamilySummary.php?ID=11 |archive-date=5 July 2018 |url-status=live }} and extinct groups from Van der Laan 2016{{cite book|last=Van der Laan|first=Richard|title=Family-group names of fossil fishes|year=2016|doi=10.13140/RG.2.1.2130.1361|url=https://www.researchgate.net/publication/317888989}} and Xu 2021.{{Cite journal|last=Xu|first=Guang-Hui|date=2021-01-09|title=A new stem-neopterygian fish from the Middle Triassic (Anisian) of Yunnan, China, with a reassessment of the relationships of early neopterygian clades|url=https://academic.oup.com/zoolinnean/article/191/2/375/5859858|journal=Zoological Journal of the Linnean Society|language=en|volume=191|issue=2|pages=375–394|doi=10.1093/zoolinnean/zlaa053|issn=0024-4082|doi-access=free}}

• Order †?Asarotiformes Schaeffer 1968
• Order †?Discordichthyiformes Minikh 1998
• Order †?Paphosisciformes Grogan & Lund 2015
• Order †?Scanilepiformes Selezneya 1985
• Order †Cheirolepidiformes Kazantseva-Selezneva 1977
• Order †Paramblypteriformes Heyler 1969
• Order †Rhadinichthyiformes
• Order †Palaeonisciformes Hay 1902
• Order †Tarrasiiformes sensu Lund & Poplin 2002
• Order †Ptycholepiformes Andrews et al. 1967
• Order †Haplolepidiformes Westoll 1944
• Order †Aeduelliformes Heyler 1969
• Order †Platysomiformes Aldinger 1937
• Order †Dorypteriformes Cope 1871
• Order †Eurynotiformes Sallan & Coates 2013
• Subclass Cladistia Pander 1860
• Order †Guildayichthyiformes Lund 2000
• Order Polypteriformes Bleeker 1859 (bichirs and reedfishes)In Nelson, Polypteriformes is placed in its own subclass Cladistia.
• Subclass Actinopteri Cope 1972 s.s.
• Order †Elonichthyiformes Kazantseva-Selezneva 1977
• Order †Phanerorhynchiformes
• Order †Bobasatraniiformes Berg 1940
• Order †Saurichthyiformes Aldinger 1937
• Subclass Chondrostei Müller, 1844
• Order †Birgeriiformes Heyler 1969
• Order †Chondrosteiformes Aldinger, 1937
• Order Acipenseriformes Berg 1940 (includes sturgeons and paddlefishes)
• Subclass Neopterygii Regan 1923 sensu Xu & Wu 2012
• Order †Pholidopleuriformes Berg 1937
• Order †Redfieldiiformes Berg 1940
• Order †Platysiagiformes Brough 1939
• Order †Polzbergiiformes Griffith 1977
• Order †Perleidiformes Berg 1937
• Order †Louwoichthyiformes Xu 2021
• Order †Peltopleuriformes Lehman 1966
• Order †Luganoiiformes Lehman 1958
• Order †Pycnodontiformes Berg 1937
• Infraclass Holostei Müller 1844
• Division Halecomorphi Cope 1872 sensu Grande & Bemis 1998
• Order †Parasemionotiformes Lehman 1966
• Order †Ionoscopiformes Grande & Bemis 1998
• Order Amiiformes Huxley 1861 sensu Grande & Bemis 1998 (bowfins)
• Division Ginglymodi Cope 1871
• Order †Dapediiformes Thies & Waschkewitz 2015
• Order †Semionotiformes Arambourg & Bertin 1958
• Order Lepisosteiformes Hay 1929 (gars)
• Clade Teleosteomorpha Arratia 2000 sensu Arratia 2013
• Order †Prohaleciteiformes Arratia 2017
• Division Aspidorhynchei Nelson, Grand & Wilson 2016
• Order †Aspidorhynchiformes Bleeker 1859
• Order †Pachycormiformes Berg 1937
• Infraclass Teleostei Müller 1844 sensu Arratia 2013
• Order †?Araripichthyiformes
• Order †?Ligulelliiformes Taverne 2011
• Order †?Tselfatiiformes Nelson 1994
• Order †Pholidophoriformes Berg 1940
• Order †Dorsetichthyiformes Nelson, Grand & Wilson 2016
• Order †Leptolepidiformes
• Order †Crossognathiformes Taverne 1989
• Order †Ichthyodectiformes Bardeck & Sprinkle 1969
• Teleocephala de Pinna 1996 s.s.
• Megacohort Elopocephalai Patterson 1977 sensu Arratia 1999 (Elopomorpha Greenwood et al. 1966)
• Order Elopiformes Gosline 1960 (ladyfishes and tarpon)
• Order Albuliformes Greenwood et al. 1966 sensu Forey et al. 1996 (bonefishes)
• Order Notacanthiformes Goodrich 1909 (halosaurs and spiny eels)
• Order Anguilliformes Jarocki 1822 sensu Goodrich 1909 (true eels)
• Megacohort Osteoglossocephalai sensu Arratia 1999
• Supercohort Osteoglossocephala sensu Arratia 1999 (Osteoglossomorpha Greenwood et al. 1966)
• Order †Lycopteriformes Chang & Chou 1977
• Order Hiodontiformes McAllister 1968 sensu Taverne 1979 (mooneye and goldeye)
• Order Osteoglossiformes Regan 1909 sensu Zhang 2004 (bony-tongued fishes)
• Supercohort Clupeocephala Patterson & Rosen 1977 sensu Arratia 2010
• Cohort Otomorpha Wiley & Johnson 2010 (Otocephala; Ostarioclupeomorpha)
• Subcohort Clupei Wiley & Johnson 2010 (Clupeomorpha Greenwood et al. 1966)
• Order †Ellimmichthyiformes Grande 1982
• Order Clupeiformes Bleeker 1859 (herrings and anchovies)
• Subcohort Alepocephali
• Order Alepocephaliformes Marshall 1962
• Subcohort Ostariophysi Sagemehl 1885
• Section Anotophysa (Rosen & Greenwood 1970) Sagemehl 1885
• Order †Sorbininardiformes Taverne 1999
• Order Gonorynchiformes Regan 1909 (milkfishes)
• Section Otophysa Garstang 1931
• Order Cypriniformes Bleeker 1859 sensu Goodrich 1909 (barbs, carp, danios, goldfishes, loaches, minnows, rasboras)
• Order Characiformes Goodrich 1909 (characins, pencilfishes, hatchetfishes, piranhas, tetras, dourado / golden (genus Salminus) and pacu)
• Order Gymnotiformes Berg 1940 (electric eels and knifefishes)
• Order Siluriformes Cuvier 1817 sensu Hay 1929 (catfishes)
• Cohort Euteleosteomorpha (Greenwood et al. 1966) (Euteleostei Greenwood 1967 sensu Johnson & Patterson 1996)
• Subcohort Lepidogalaxii
• Order Lepidogalaxiiformes Betancur-Rodriguez et al. 2013 (salamanderfish)
• Subcohort Protacanthopterygii Greenwood et al. 1966 sensu Johnson & Patterson 1996
• Order Argentiniformes (barreleyes and slickheads) (formerly in Osmeriformes)
• Order Galaxiiformes
• Order Salmoniformes Bleeker 1859 sensu Nelson 1994 (salmon, trout and pike)
• Subcohort Stomiati
• Order Osmeriformes (smelts)
• Order Stomiiformes Regan 1909 (bristlemouths and marine hatchetfishes)
• Subcohort Neoteleostei Nelson 1969
• Infracohort Ateleopodia
• Order Ateleopodiformes (jellynose fish)
• Infracohort Eurypterygia Rosen 1973
• Section Aulopa [Cyclosquamata Rosen 1973]
• Order Aulopiformes Rosen 1973 (Bombay duck and lancetfishes)
• Section Ctenosquamata Rosen 1973
• Subsection Myctophata [Scopelomorpha]
• Order Myctophiformes Regan 1911 (lanternfishes)
• Subsection Acanthomorpha Betancur-Rodriguez et al. 2013
• Division Lampridacea Betancur-Rodriguez et al. 2013 [Lampridomorpha; Lampripterygii]
• Order Lampriformes Regan 1909 (oarfish, opah and ribbonfishes)
• Division Paracanthomorphacea sensu Grande et al. 2013 (Paracanthopterygii Greenwood 1937)
• Order Percopsiformes Berg 1937 (cavefishes and trout-perches)
• Order †Sphenocephaliformes Rosen & Patterson 1969
• Order Zeiformes Regan 1909 (dories)
• Order Gadiformes Goodrich 1909 (cods)
• Division Polymixiacea Betancur-Rodriguez et al. 2013 (Polymyxiomorpha; Polymixiipterygii)
• Order †Pattersonichthyiformes Gaudant 1976
• Order †Ctenothrissiformes Berg 1937
• Order Polymixiiformes Lowe 1838 (beardfishes)
• Division Euacanthomorphacea Betancur-Rodriguez et al. 2013 (Euacanthomorpha sensu Johnson & Patterson 1993; Acanthopterygii Gouan 1770 sensu])
• Order Trachichthyiformes (fangtooths and pineconefishes)
• Subdivision Berycimorphaceae Betancur-Rodriguez et al. 2013
• Order Beryciformes (alfonsinos and holocentrids) (incl. Holocentriformes,Stephanoberyciformes; Cetomimiformes)
• Subdivision Percomorphaceae Betancur-Rodriguez et al. 2013 (Percomorpha sensu Miya et al. 2003; Acanthopteri)
• Series Ophidiimopharia Betancur-Rodriguez et al. 2013
• Order Ophidiiformes (pearlfishes)
• Series Batrachoidimopharia Betancur-Rodriguez et al. 2013
• Order Batrachoidiformes (toadfishes)
• Series Gobiomopharia Betancur-Rodriguez et al. 2013
• Order Gobiiformes (cardinalfishes, sleepers and gobies)
• Series Scombrimopharia Betancur-Rodriguez et al. 2013
• Order Syngnathiformes (seahorses, pipefishes, sea moths, cornetfishes and flying gurnardsIn Nelson and ITIS, Syngnathiformes is placed as the suborder Syngnathoidei of the order Gasterosteiformes.)
• Order Scombriformes (Tunas and (mackerels)
• Series Carangimopharia Betancur-Rodriguez et al. 2013
• Subseries Anabantaria Betancur-Rodriguez et al. 2014
• Order Synbranchiformes (swamp eels)
• Order Anabantiformes (Labyrinthici) (gouramies, snakeheads, )
• Subseries Carangaria Betancur-Rodriguez et al. 2014
• Order Carangiformes (Jack mackerels, pompanos, flatfishes, billfishes)
• Subseries Ovalentaria Smith & Near 2012 (Stiassnyiformes sensu Li et al. 2009)
• Order Atheriniformes Rosen 1964 (silversides and rainbowfishes)
• Order Cyprinodontiformes Berg 1940 (livebearers, killifishes)
• Order Beloniformes Berg 1940 (flyingfishes and ricefishes)
• Order Cichliformes Betancur-Rodriguez et al. 2013 (Cichlids, Convict blenny, leaf fishes)
• Order Mugiliformes Berg 1940 (mullets)
• Order Blenniiformes Springer 1993 (Blennies, damselfish,Clingfishes)
• Series Eupercaria Betancur-Rodriguez et al. 2014 (Percomorpharia Betancur-Rodriguez et al. 2013)
• Order Perciformes Bleeker 1859
• Order Centrarchiformes Bleeker 1859 (Sunfishes and mandarin fishes)
• Order Labriformes (Wrasses and Parrotfishes)
• Order Acropomatiformes
• Order Acanthuriformes
• Order Lophiiformes Garman 1899 (Anglerfishes)
• Order Tetraodontiformes Regan 1929 (Filefishes and pufferfish)

{{clear}}

{{Reflist|20em}}

• {{Commons category-inline}}
• {{Wikispecies-inline}}

{{Actinopterygii|}}

{{Chordata}}

{{Evolution of fish}}

{{Fins, limbs and wings}}

{{Taxonbar|from=Q127282}}

{{Authority control}}

Category:Fish classes

Category:Extant Silurian first appearances