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 skin supported by radially extended thin bony spines called lepidotrichia, as opposed to the bulkier, fleshy lobed fins of the sister class Sarcopterygii. Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton.
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 perch and darters (Percidae), sea bass and groupers (Serranidae).
The bowfin is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. It is one of two species in the genus Amia, along with Amia ocellicauda, the eyespot bowfin. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
Teleostei, members of which are known as teleosts, is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, and contains 96% of all extant species of fish. Teleosts are arranged into about 40 orders and 448 families. Over 26,000 species have been described. Teleosts range from giant oarfish measuring 7.6 m (25 ft) or more, and ocean sunfish weighing over 2 t, to the minute male anglerfish Photocorynus spiniceps, just 6.2 mm (0.24 in) 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 seahorses.
Neopterygii is a subclass of ray-finned fish (Actinopterygii). Neopterygii includes the Holostei and the Teleostei, of which the latter comprise the vast majority of extant fishes, and over half of all living vertebrate species. While living holosteans include only freshwater taxa, teleosts are diverse in both freshwater and marine environments. Many new species of teleosts are scientifically described each year.
The Osmeriformes are an order of ray-finned fish that includes the true or freshwater smelts and allies, such as the galaxiids and noodlefishes; they are also collectively called osmeriforms. They belong to the teleost superorder Protacanthopterygii, which also includes pike and salmon, among others. The order's name means "smelt-shaped", from Osmerus + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek osmé + Latin forma, the former in reference to the characteristic aroma of the flesh of Osmerus.
Beloniformes is an order composed of six families of freshwater and marine ray-finned fish:
Blenny is a common name for many types of fish, including several families of percomorph marine, brackish, and some freshwater fish sharing similar morphology and behaviour. Six families are considered "true blennies", grouped under the order Blenniiformes; its members are referred to as blenniiformids. About 151 genera and nearly 900 species have been described within the order. The order was formerly classified as a suborder of the Perciformes but the 5th Edition of Fishes of the World divided the Perciformes into a number of new orders and the Blenniiformes were placed in the percomorph clade Ovalentaria alongside the such taxa as Cichliformes, Mugiliformes and Gobiesociformes.
Nitric oxide synthases (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, insulin secretion, airway tone, and peristalsis, and is involved in angiogenesis and neural development. It may function as a retrograde neurotransmitter. Nitric oxide is mediated in mammals by the calcium-calmodulin controlled isoenzymes eNOS and nNOS. The inducible isoform, iNOS, involved in immune response, binds calmodulin at physiologically relevant concentrations, and produces NO as an immune defense mechanism, as NO is a free radical with an unpaired electron. It is the proximate cause of septic shock and may function in autoimmune disease.
Caproidae, or boarfishes, are a small family of marine fishes comprising two genera and 19 species. These fishes are found throughout the world in temperate and tropical seas.
A fish 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 fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communicate acoustically with each other, such as during courtship displays.
The Gobiiformes are an order of fish that includes the gobies and their relatives. The order, which was previously considered a suborder of Perciformes, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobiiformes have been elucidated using molecular data. Gobiiforms are primarily small species that live in marine water, but roughly 10% of these species inhabit fresh water. This order is composed chiefly of benthic or burrowing species; like many other benthic fishes, most gobiiforms do not have a gas bladder or any other means of controlling their buoyancy in water, so they must spend most of their time on or near the bottom. Gobiiformes means "goby-like".
Nitric oxide synthase, inducible is an enzyme which is encoded by the NOS2 gene in humans and mice.
Fish are very diverse animals and can be categorised in many ways. Although most fish species have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase about 34,800 species of fish had been described as of February 2022, which is more than the combined total of all other vertebrate species: mammals, amphibians, reptiles and birds.
Percomorpha is a large clade of ray-finned fish with more than 17 000 known species that includes the tuna, seahorses, gobies, cichlids, flatfish, wrasse, perches, anglerfish, and pufferfish.
Otocephala is a clade of ray-finned fishes within the infraclass Teleostei that evolved some 230 million years ago. It is named for the presence of a hearing (otophysic) link from the swimbladder to the inner ear. Other names proposed for the group include Ostarioclupeomorpha and Otomorpha.
The Trachichthyiformes are an order of ray-finned fishes in the superorder Acanthopterygii.
Teleosteomorpha is a clade of ray-finned fishes containing all teleost fish and their closest extinct relatives. Also in this group are two diverse Mesozoic fish orders, the Aspidorhynchiformes and the Pachycormiformes. Several other non-teleostomorph teleosteans existed throughout the Mesozoic, although not as dominant as the two main clades in the group.
Lamprimorpha is a superorder of marine ray-finned fishes, representing a basal group of the highly diverse clade Acanthomorpha. Represented today only by the order Lampriformes, recent studies have recovered other basal fossil species of the group dating as far back as the Cenomanian stage of the Late Cretaceous. Some of these fossil taxa, such as the paraphyletic genus Aipichthys, are among the oldest known fossil acanthomorphs, and overall they appear to have been a major component of the marine fish fauna at that time. Lamprimorpha is thought to be the sister group to the superorder Paracanthopterygii, which contains cod, dories, and trout-perches; however, Lamprimorpha may instead be sister to Acanthopterygii.
