Neopterygii (from Greek νέος ''neos'' 'new' and πτέρυξ ''pteryx'' 'fin') is a subclass of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

(Actinopterygii). Neopterygii includes the Holostei and the

Teleostei Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...

, of which the latter comprise the vast majority of extant

fishes A fish (: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed ...

, and over half of all living

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. While living holosteans include only freshwater

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

, teleosts are diverse in both

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

and marine environments. Many new species of teleosts are scientifically described each year. The potentially oldest known neopterygian is the putative " semionotiform" '' Acentrophorus varians'' from the

Middle Permian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

of Russia; however, one study incorporating morphological data from

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

and molecular data from

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics * Nuclear space *Nuclear ...

and

mitochondrial A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

, places this

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...

date at least 284 mya (million years ago), during the Artinskian stage of the Early

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

. Another study suggests an even earlier split (360 myr ago, near the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

boundary).

Evolution and diversity

Living neopterygians are subdivided into two main groups (

infraclass In biology, taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of or ...

es): teleosts and holosteans. Holosteans comprise two

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

, the Ginglymodi and the Halecomorphi. All of these groups have a long and extensive

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

. The evolutionary relationships between the different groups of Neopterygii is summarized in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below (

time for each

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

in mya are based on). Neopterygians are a very speciose group. They make up over 50% of the total

diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...

today, and their diversity grew since the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

era. However, the diversity of the various groups of neopterygians (or of

in general) is unevenly distributed, with teleosts making up the vast majority (96%) of living species. Watsonulus eugnathoides

Early in their

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

, neopterygians were a very successful group of fish, because they could 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 Electroreception and electrogenesis are the closely related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes, such ...

and the ampullae of Lorenzini are present in all other extant groups of fish (except for

hagfish Hagfish, of the Class (biology), class Myxini (also known as Hyperotreti) and Order (biology), order Myxiniformes , are eel-shaped Agnatha, jawless fish (occasionally called slime eels). Hagfish are the only known living Animal, animals that h ...

), neopterygians have lost this sense, even if it has later re-evolved within Gymnotiformes and

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

es, which possess non-homologous teleost ampullae. Only a few changes occurred during the evolution of neopterygians from the earlier actinopterygians. However, a very important step in the evolution of neopterygians is the acquisition of a better control of the movements of both

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

s, resulting in an improvement in their swimming capabilities. They additionally acquired several modifications in the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

, which allowed the evolution of different

feeding Eating (also known as consuming) is the ingestion of food. In biology, this is typically done to provide a heterotrophic organism with energy and nutrients and to allow for growth. Animals and other heterotrophs must eat in order to survive – ...

mechanisms and consequently the colonization of new ecological niches. All of these characters represented major improvements, resulting in Neopterygii becoming the dominant group of fishes (and, thus, taxonomically of

vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

in general) today. The great diversity of extant teleosts has been linked to a whole genome duplication event during their evolution.

Classification

* Order † Pholidopleuriformes * Order † Redfieldiiformes * Order † Platysiagiformes * Order † Polzbergiiformes * Order † Perleidiformes * Order † Louwoichthyiformes * Order † Peltopleuriformes * Order † Luganoiiformes * Order †

Pycnodontiformes Pycnodontiformes is an extinct order of primarily marine bony fish. The group first appeared during the Late Triassic and disappeared during the Eocene. The group has been found in rock formations in Africa, Asia, Europe, North and South America. ...

* Infraclass Holostei **Clade Halecomorphi ***Order † Parasemionotiformes ***Order † Panxianichthyiformes ***Order † Ionoscopiformes ***Order

Amiiformes The Amiiformes order (biology), order of fish has only two extant taxa, extant species, the bowfins: ''Amia calva'' and ''Amia ocellicauda'', the latter recognized as a separate species in 2022. These Amiiformes are found in the freshwater syste ...

, the bowfin **Clade Ginglymodi ***Order †? Dapediiformes ***Order Semionotiformes ***Order Lepisosteiformes, the gars *Clade Teleosteomorpha **Order † Prohaleciteiformes ** Division Aspidorhynchei ***Order † Aspidorhynchiformes ***Order Pachycormiformes * Infraclass

** Order †? Araripichthyiformes ** Order †? Ligulelliiformes ** Order † Pholidophoriformes ** Order † Dorsetichthyiformes ** Order † Leptolepidiformes ** Order † Crossognathiformes ** Order †

Ichthyodectiformes Ichthyodectiformes is an Extinction, extinct order of marine stem-teleost ray-finned fish. The order is named after the genus ''Ichthyodectes'', established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of th ...

** Order † Tselfatiiformes ** Superorder Osteoglossomorpha *** Order † Lycopteriformes ***Order Osteoglossiformes, the bony-tongued fishes *** Order Hiodontiformes, including the mooneye and goldeye ** Superorder Elopomorpha *** Order Elopiformes, including the ladyfishes and tarpon *** Order Albuliformes, the bonefishes *** Order Notacanthiformes, including the halosaurs and spiny eels *** Order

Anguilliformes Eels are ray-finned fish belonging to the order (biology), order Anguilliformes (), which consists of eight suborders, 20 Family (biology), families, 164 genus, genera, and about 1000 species. Eels undergo considerable development from the earl ...

, the true eels *** Order Saccopharyngiformes, including the gulper eel ** Superorder Clupeomorpha *** Order † Ellimmichthyiformes ***Order

Clupeiformes Clupeiformes is the order of ray-finned fish that includes the herring family, Clupeidae, and the anchovy family, Engraulidae and sardines. The group includes many of the most important forage and food fish. Clupeiformes are physostomes, ...

, including

herring Herring are various species of forage fish, belonging to the Order (biology), order Clupeiformes. Herring often move in large Shoaling and schooling, schools around fishing banks and near the coast, found particularly in shallow, temperate wate ...

s and anchovies ** Superorder

Ostariophysi Ostariophysi is the second-largest superorder of fish. Members of this superorder are called ostariophysians. This diverse group contains 10,758 species, about 28% of known fish species in the world and 68% of freshwater species, and are present ...

*** Order † Sorbininardiformes ***Order Gonorynchiformes, including the milkfishes *** Order

Cypriniformes Cypriniformes is an order of ray-finned fish, which includes many families and genera of cyprinid ( carps and their kin) fish, such as barbs, loaches, botias, and minnows (among others). Cypriniformes is an "order-within-an-order", placed ...

, including barbs,

carp The term carp (: carp) is a generic common name for numerous species of freshwater fish from the family (biology), family Cyprinidae, a very large clade of ray-finned fish mostly native to Eurasia. While carp are prized game fish, quarries and a ...

, danios,

goldfish The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of the order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the w ...

es, loaches, minnows, rasboras *** Order Characiformes, including characins, pencilfishes, hatchetfishes, piranhas, tetras. *** Order Gymnotiformes, including

electric eel The electric eels are a genus, ''Electrophorus'', of neotropical freshwater fish from South America in the family Gymnotidae, of which they are the only members of the subfamily Electrophorinae. They are known for their electric fish, ability ...

s and knifefishes *** Order Siluriformes, the

es ** Superorder Lepidogalaxii ***Order Lepidogalaxiiformes, the salamanderfish **Superorder

Protacanthopterygii Protacanthopterygii is a superorder of ray-finned fish. They inhabit both Marine (ocean), marine and freshwater habitats. They appear to have evolved in the Cretaceous or perhaps late Jurassic, originating probably roughly 150 million years ago; ...

*** Order Argentiniformes, including the barreleyes and slickheads (formerly in Osmeriformes) *** Order Salmoniformes, including

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

Arctic char The Arctic char or Arctic charr (''Salvelinus alpinus'') is a cold-water fish in the family Salmonidae, native to alpine lakes, as well as Arctic and subarctic coastal waters in the Holarctic realm, Holarctic. Distribution and habitat It Spaw ...

, and

trout Trout (: trout) is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of which are members of the subfamily Salmoninae in the ...

*** Order

Esociformes The Esocoidei () is a small suborder of freshwater Actinopterygii, ray-finned fish, one of two suborders in the order Salmoniformes. It contains two families, Umbridae and Esocidae. The pikes of genus ''Esox'' give the order its name. This order ...

, the pikes and mudminnows ***Order Galaxiiformes, the galaxiids *** Order Osmeriformes, including the smelts ** Superorder Stenopterygii (may belong in Protacanthopterygii) *** Order Ateleopodiformes, the jellynose fish *** Order

Stomiiformes Stomiiformes is an order (biology), order of deep-sea ray-finned fishes of very diverse Morphology (biology), morphology. It includes, for example, Barbeled dragonfish, dragonfishes, lightfishes (Gonostomatidae and Phosichthyidae), loosejaws, ma ...

, including the bristlemouths and marine hatchetfishes ** Superorder Cyclosquamata (may belong in Protacanthopterygii) *** Order

Aulopiformes Aulopiformes is a diverse order (biology), order of Marine (ocean), marine ray-finned fish consisting of some 15 Extant taxon, extant and several prehistoric family (biology), families with about 45 genera and over 230 species. The common names ...

, including the Bombay duck, tripod fish, and lancetfishes ** Superorder Scopelomorpha *** Order Myctophiformes, including the

lanternfish Lanternfish (or myctophids, from the Greek language, Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family (biology), family Myctophidae. One of two families in the order Myctophiformes, ...

es ** Superorder Lampridiomorpha *** Order Lampriformes, including the oarfish, opah and ribbonfishes ** Superorder Polymyxiomorpha *** Order † Pattersonichthyiformes ***Order † Ctenothrissiformes ***Order Polymixiiformes, the beardfishes ** Superorder

Paracanthopterygii Paracanthopterygii is a superorder of fishes. Members of this group are called paracanthopterygians. The oldest members are known as fossils from the Cenomanian. It includes five orders: * † Sphenocephaliformes * Percopsiformes ( trout-perche ...

*** Order

Percopsiformes The Percopsiformes are a small order of freshwater teleost fishes measuring less than 20 cm in length, comprising the trout-perch and its allies. It contains just ten extant taxon, extant species, grouped into seven genus, genera and three ...

, including the cavefishes and trout-perches ***Order † Sphenocephaliformes *** Order Batrachoidiformes, the toadfishes *** Order Lophiiformes, including the

anglerfish The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common name, common and scientific name comes from the characteristic mode of predation, in which a modified dorsal Fish fin#Ray-fins, fin ray acts as a Aggressiv ...

es *** Order

Gadiformes Gadiformes , also called the Anacanthini, are an order of ray-finned fish that include the cod, hakes, pollock, haddock, burbot, rocklings and moras, many of which are food fish of major commercial value. They are mostly marine fish found thr ...

, including

cod Cod (: cod) is the common name for the demersal fish genus ''Gadus'', belonging to the family (biology), family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gad ...

s *** Order Ophidiiformes, including the pearlfishes ** Superorder

Acanthopterygii Acanthopterygii (meaning "spiny-finned one") is a superorder of teleost, bony fishes in the class Actinopterygii. Members of this superorder are sometimes called ray-finned fishes for the characteristic sharp, bony rays in their fins; however th ...

*** Order Mugiliformes, the mullets *** Order

Atheriniformes The Atheriniformes, also known as the silversides, are an order of ray-finned fishes that includes the Old & New World silversides, the rainbowfishes, and several less-familiar families, including the unusual Phallostethidae. The order incl ...

, including silversides and

rainbowfish Rainbowfishes are small, colourful freshwater fishes belonging to the Family (biology), family Melanotaeniidae, found in northern and eastern Australia, New Guinea (including islands in Cenderawasih Bay and Raja Ampat Islands in Indonesia), Sula ...

es *** Order

Beloniformes Beloniformes is an order composed of six families (and about 264 species) of freshwater and marine ray-finned fish: * Adrianichthyidae (ricefish and medakas) * Belonidae (needlefish) * Exocoetidae (flyingfishes) * Hemiramphidae (halfb ...

, including the flyingfishes *** Order Cetomimiformes, the

whalefish The Cetomimoidea or whalefishes are a superfamily of small, deep-sea ray-finned fish. Formerly treated as either their own order (Cetomimiformes) due to their unusual anatomy, more recent studies incorporating genetic data confirm them to be dee ...

es *** Order

Cyprinodontiformes Cyprinodontiformes is an order (biology), order of Actinopterygii, ray-finned fish, comprising mostly small, freshwater fish. Many popular aquarium fish, such as killifish and Poeciliidae, live-bearers, are included. They are closely related t ...

, including live-bearers, killifishes *** Order

Stephanoberyciformes The Stephanoberycoidei is a suborder of marine ray-finned fishes, consisting of about 68 species, the majority (61) of which belong to the ridgehead family (biology), family (Melamphaidae). They were formerly placed as their own order, the Stepha ...

, including the

ridgehead Ridgeheads, also known as bigscales, are a family (Melamphaidae, from the Greek ''melanos'' lackand ''amphi'' y both sides of small, deep-sea beryciform fish. The family contains approximately 37 species in five genera; their distribution is ...

s *** Order Beryciformes, including the fangtooths and pineconefishes *** Order

Zeiformes The Zeiformes are a small order of exclusively marine ray-finned fishes most notable for the dories, a group of common food fish. The order consists of about 33 species in six extant families, mostly deep-sea types. The boarfishes ( Caproidae) ...

, including the dories *** Order Gobiesociformes, the

clingfish Clingfishes are ray-finned fishes of the family Gobiesocidae, the only family in the suborder Gobiesocoidei of the order Blenniiformes. These fairly small to very small fishes are widespread in tropical and temperate regions, mostly near the coa ...

es *** Order

Gasterosteiformes Gasterosteoidei is a suborder of ray-finned fishes that includes the sticklebacks and relatives, the 5th edition of ''Fishes of the World'' classifies this suborder within the order Scorpaeniformes. Systematics Gasterosteoidei is treated as a ...

including

stickleback The sticklebacks are a family of ray-finned fishes, the Gasterosteidae which have a Holarctic distribution in fresh, brackish and marine waters. They were thought to be related to the pipefish and seahorses but are now thought to be more close ...

s *** Order Syngnathiformes, including the seahorses and pipefishesIn ITIS, Syngnathiformes is placed as the suborder

Syngnathoidei The Syngnathiformes are an order of ray-finned fishes that includes the leafy seadragons, sea moths, trumpetfishes and seahorses, among others.FishBase (2005)Order Summary for Syngnathiformes Version of 2005-FEB-15. Retrieved 19 Aug 2008. Th ...

of the order

. *** Order

Synbranchiformes Synbranchiformes, often called swamp eels, though that name can also refer specifically to Synbranchidae, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii. ...

, including the swamp eels *** Order

Tetraodontiformes Tetraodontiformes (), also known as the Plectognathi, is an order of ray-finned fishes which includes the pufferfishes and related taxa. This order has been classified as a suborder of the order Perciformes, although recent studies have found ...

, including the sunfish, filefishes and

pufferfish Tetraodontidae is a family of marine and freshwater fish in the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowers, blowies, bubblefish, globefish, swellfis ...

*** Order Pleuronectiformes, the

flatfish A flatfish is a member of the Ray-finned fish, ray-finned demersal fish Order (biology), suborder Pleuronectoidei, also called the Heterosomata. In many species, both eyes lie on one side of the head, one or the other migrating through or around ...

es *** Order

Scorpaeniformes The Scorpaeniformes are a diverse Order (biology), order of Actinopterygii, ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of spec ...

, including scorpionfishes and the sculpins *** Order

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

40% of all fish including anabantids,

bass Bass or Basses may refer to: Fish * Bass (fish), various saltwater and freshwater species Wood * Bass or basswood, the wood of the tilia americana tree Music * Bass (sound), describing low-frequency sound or one of several instruments in th ...

cichlid Cichlids () are a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with on ...

gobies Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising over 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the fam ...

gourami Gouramis, or gouramies , are a group of fresh water, freshwater Anabantiformes, anabantiform fish that comprise the family (biology), family Osphronemidae. The fish are native to Asia—from the Indian Subcontinent to Southeast Asia and northeas ...

mackerel Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment. ...

perch Perch is a common name for freshwater fish from the genus ''Perca'', which belongs to the family Percidae of the large order Perciformes. The name comes from , meaning the type species of this genus, the European perch (''P. fluviatilis'') ...

es, scats, whiting, wrasses

References

{{Taxonbar, from=Q740005 Lopingian first appearances Extant Permian first appearances Taxa named by Charles Tate Regan