Fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

vary greatly in size. The

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of .McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, D ...

and

basking shark The basking shark (''Cetorhinus maximus'') is the second-largest living shark and fish, after the whale shark, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Adults typically reach in length. ...

exceed all other fish by a considerable margin in weight and length. Fish are a

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

group that describes aquatic vertebrates while excluding

tetrapods Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids ...

, and the

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...

that often represent the group are more closely related to

cetaceans Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

such as whales, than to the

cartilaginous fish Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue ...

such as sharks and rays. As such, cross group comparisons on this page only serve a colloquial purpose.

Largest extant fish

Jawless fish (Agnatha)

* Hagfish ( Myxini) :The

hagfish Hagfish, of the class Myxini (also known as Hyperotreti) and order Myxiniformes , are eel-shaped, slime-producing marine fish (occasionally called slime eels). They are the only known living animals that have a skull but no vertebral column, a ...

, which are not taxonomically true fish, are among the most primitive extant vertebrates. There is only one order and family in this animal class. All of the 77 known species have elongated, eel-like bodies but can be distinguished by their downward-facing mouths. The largest form is the Goliath hagfish (''Eptatretus goliath''). This species can range up to in length and weigh to . * Lampreys (

Petromyzontiformes Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like s ...

)

:As with the hagfish, lampreys appear eel-like in shape. They have cartilaginous skeletons and have been evolving separately from any other group for over 400 million years. They are predatory and often attach themselves to a fish or other small animal and gradually drain blood and organs. The largest species is the

sea lamprey The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish". Description The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ro ...

(''Petromyzon marinus''), which can grow to and weigh .

Armored fish (Placodermi)

The largest fish of the now-extinct class

Placodermi Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally 'Plate (animal anatomy), plate-skinned') is a Class (biology), class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devoni ...

was the giant predatory ''

Dunkleosteus ''Dunkleosteus'' is an extinct genus of large armored, jawed fishes that existed during the Late Devonian period, about 382–358 million years ago. It consists of ten species, some of which are among the largest placoderms to have ever lived: ...

''. The largest and most well known species was ''D. terrelli'', which grew almost in length and in weight. Its filter feeding relative, ''

Titanichthys ''Titanichthys'' is an extinct genus of giant, aberrant marine placoderm from shallow seas of the Late Devonian of Morocco, Eastern North America, and possibly Europe. Many of the species approached ''Dunkleosteus'' in size and build. Unlike ...

'', may have rivaled it in size. ''Titanichthys'' reached a length of though in older paper it was estimated at .

Cartilaginous fish (Chondrichthyes)

The cartilaginous fish are not directly related to the "bony fish," but are sometimes lumped together for simplicity in description. The largest living

, of the order

Orectolobiformes Carpet sharks are sharks classified in the order Orectolobiformes . Sometimes the common name "carpet shark" (named so because many species resemble ornately patterned carpets) is used interchangeably with "wobbegong", which is the common name ...

, is the

(''Rhincodon typus''), of the world's tropical oceans. It is also the largest living animal that is not a

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

and, like the largest whales, it is a docile creature that filter-feeds on tiny

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

. An average adult of this species measures long and weighs an average of 9 tonnes. The largest verified specimen was caught in 1949 off

Karachi, Pakistan Karachi (; ur, ; ; ) is the most populous city in Pakistan and 12th most populous city in the world, with a population of over 20 million. It is situated at the southern tip of the country along the Arabian Sea coast. It is the former cap ...

and was long and weighed 21.5 tonnes. Although many are dubious, there are several reports of larger whale sharks, with reliable sources citing unverified specimens of up to 37 tonnes and . * Ground sharks (

Carcharhiniformes Carcharhiniformes , the ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and the sandbar shark. Members of this order are characterized by the presenc ...

)

:The largest species of this order is the widely distributed

tiger shark The tiger shark (''Galeocerdo cuvier'') is a species of requiem shark and the last extant member of the family Galeocerdonidae. It is a large macropredator, capable of attaining a length over . Populations are found in many tropical and tempera ...

(''Galeocerdo cuvier''). Specimens have been verified to at least but even larger ones have been reported. One specimen, a gravid female caught off Australia and measuring only long, weighed an exceptional . A female caught in 1957 reportedly measured and weighing , although this very outsized shark is not known to have been confirmed. The largest of the infamous "requiem sharks" (in the genus ''

Carcharhinus ''Carcharhinus'' is the type genus of the family Carcharhinidae, the requiem sharks. One of 12 genera in its family, it contains over half of the species therein. It contains 35 extant and eight extinct species to date, with likely more species y ...

'') seems to be the dusky shark (''C. obscurus''), at up to and a weight of . However, the bulkier

bull shark The bull shark (''Carcharhinus leucas''), also known as the Zambezi shark (informally zambi) in Africa and Lake Nicaragua shark in Nicaragua, is a species of requiem shark commonly found worldwide in warm, shallow waters along coasts and in riv ...

(''C. leucas'') has been estimated to weigh about in recent specimens that measured over long. The

silky shark The silky shark (''Carcharhinus falciformis''), also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the f ...

(''C. falciformis'') is another contender for the largest requiem shark at a maximum weight of and a maximum length of around . The largest

hammerhead shark The hammerhead sharks are a group of sharks that form the family Sphyrnidae, so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Most hammerhe ...

is the

great hammerhead The great hammerhead (''Sphyrna mokarran'') or great hammerhead shark is the largest species of hammerhead shark, belonging to the family Sphyrnidae, attaining an average length of and reaching a maximum length of . It is found in tropical and w ...

(''Sphyrna mokarran''), which can reach and weigh . The most species-rich shark family, the catsharks, are fairly small-bodied. The largest, the

nursehound The nursehound (''Scyliorhinus stellaris''), also known as the large-spotted dogfish, greater spotted dogfish or bull huss, is a species of catshark, belonging to the family Scyliorhinidae, found in the northeastern Atlantic Ocean. It is general ...

(''Scyliorhinus stellaris''), can grow up to and a weight of at least . * Chimaeras ( Chimaeriformes) :These odd, often translucent cartilaginous fish are typically quite small. The largest species is the carpenter's chimaera (''Chimaera lignaria'') of the oceans near Australia and New Zealand. It can reach up to in length and weigh . * Frill sharks and cow sharks (

Hexanchiformes The Hexanchiformes are the order consisting of the most primitive types of sharks, and numbering just seven extant species. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens. Hexanchi ...

) :The largest frill sharks and cow shark is the

Bluntnose sixgill shark The bluntnose sixgill shark (''Hexanchus griseus''), often simply called the cow shark, is the largest hexanchoid shark, growing to in length. It is found in tropical and temperate waters worldwide and its diet is widely varied by region. The ...

(''Hexanchus griseus''). This large species typically inhabits depths greater than , and has been recorded as deep as . The largest specimen known (caught off Cuba) reportedly weighed and measured long. * Bullhead sharks ( Heterodontiformes) :These tropical, small sharks are noted for their broad head shape. The largest species is the

Port Jackson shark The Port Jackson shark (''Heterodontus portusjacksoni'') is a nocturnal, oviparous (egg laying) type of bullhead shark of the family (biology), family Bullhead shark, Heterodontidae, found in the coastal region of southern Australia, including th ...

(''Heterodontus portusjacksoni'') of Australasian waters, at up to long and weighing up to . * Mackerel sharks (

Lamniformes The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order (biology), order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, ...

)

:Most species in this order grow quite large. The largest living species is the

(''Cetorhinus maximus'') of the world's northern temperate oceans, also the second largest fish. The largest specimen, which was examined in 1851, measured long and weighed 16 tonnes. Perhaps the most famous "big fish" is the

great white shark The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is nota ...

(''Carcharodon carcharias''). Specimens have been measured up to and weighing , with great whites of at least long generally accepted. The

common thresher The common thresher (''Alopias vulpinus''), also known as Atlantic thresher, is the largest species of thresher shark, family Alopiidae, reaching some in length. About half of its length consists of the elongated upper lobe of its caudal fin. Wi ...

(''Alopias vulpinus''), can grow to and weigh over , but much of its length is comprised by its extreme tail. Odd and recently discovered giants also live in this order: the slender, sword-snouted

goblin shark The goblin shark (''Mitsukurina owstoni'') is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This pink-skinned anima ...

(''Mitsukurina owstoni''), with unweighed specimens of up to approximately , and the massive

megamouth shark The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant taxon, extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. ...

(''Megachasma pelagios''), up to long and a weight of . :The largest shark in the fossil record is the

megalodon Megalodon (''Otodus megalodon''), meaning "big tooth", is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. It was formerly thought to be a member ...

(''Otodus megalodon''), a colossal

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

lamniform. The range of estimates of the maximum length for megalodon are from , with a mass ranging from . It is also regarded as the largest macro-predatory fish ever. * Stingrays and allies (

Myliobatiformes Myliobatiformes () is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic grou ...

)

:Both the largest species of this order and the largest of all rays is the

giant oceanic manta ray The giant oceanic manta ray, giant manta ray, or oceanic manta ray (''Mobula birostris'') is a species of ray in the family Mobulidae, and the largest type of ray in the world. It is circumglobal and is typically found in tropical and subtropica ...

(''Manta birostris''). This peaceful leviathan can reach a size of , a "disk" width of and a total length of . A related species reaches barely smaller sizes, the

devil fish The devil fish or giant devil ray (''Mobula mobular'') is a species of ray in the family Mobulidae. It is currently listed as endangered, mostly due to bycatch mortality in unrelated fisheries. Description The devil fish is larger than its clo ...

(''Mobula mobular''). It can grow up to a disk width, a total length of and a weight of at least . The largest

stingray Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae ( ...

is generally accepted to be the

short-tail stingray The short-tail stingray or smooth stingray (''Bathytoshia brevicaudata'') is a common species of stingray in the family Dasyatidae. It occurs off southern Africa, typically offshore at a depth of , and off southern Australia and New Zealand, f ...

(''Dasyatis brevicaudata''), found off the southern tip of Africa and Australasia, at up to across the disk and weighing more than . Although there are several large stingrays that at least approach this species' size. One, the

giant freshwater stingray The giant freshwater stingray (''Urogymnus polylepis'', also widely known by the junior synonym ''Himantura chaophraya'') is a species of stingray in the family Dasyatidae. It is found in large rivers and estuaries in Southeast Asia and Borneo, ...

(''Himantura polylepis''), of the large rivers of South Asia, can weigh up to , measure up to in total length and have a disc span of . * Carpet sharks (

) :The whale shark is the largest species in this order, reaching up to 20 meters long when fully mature. No other species in the order even approaches this size. The next largest species is the

nurse shark The nurse shark (''Ginglymostoma cirratum'') is an elasmobranch fish in the family Ginglymostomatidae. The conservation status of the nurse shark is globally assessed as Vulnerable in the IUCN List of Threatened Species. They are considered t ...

(''Ginglymostoma cirratum''), which can grow up to across the disk and weighing more than . * Sawfish (

Pristiformes Sawfish, also known as carpenter sharks, are a Family (biology), family of batoidea, rays characterized by a long, narrow, flattened rostrum (anatomy), rostrum, or nose extension, lined with sharp transverse plane, transverse teeth, arranged i ...

) :Distinguished by a long snout decorated with sharp teeth on the sides, these little-known cartilaginous fish are often reported to attain huge sizes. The definitive largest species is not known, although the

smalltooth sawfish The smalltooth sawfish (''Pristis pectinata'') is a species of sawfish in the family Pristidae. It is found in shallow tropical and subtropical waters in coastal and estuarine parts of the Atlantic. Reports from elsewhere are now believed to be m ...

(''Pristis pectinata'') and the

green sawfish The longcomb sawfish, narrowsnout sawfish or green sawfish (''Pristis zijsron'') is a species of sawfish in the family Pristidae, found in tropical and subtropical waters of the Indo-West Pacific. It has declined drastically and is now considered ...

(''P. zijsron''), at up to reportedly , respectively, may be the largest. Weights of up to have been reported, possibly for the smalltooth species, but are not verified. The large-tooth sawfish (''P. pristis'') and

freshwater sawfish The largetooth sawfish (''Pristis pristis'', syn. ''P. microdon'' and ''P. perotteti'') is a species of sawfish, family Pristidae. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined dra ...

(''P. microdon'') can both exceed . * Sawsharks ( Pristiophoriformes) :Despite sharing a similar appearing snout adapted in both to shred fish prey, the sawsharks are typically much smaller than

sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish wi ...

. The largest sawshark is the

Sixgill sawshark The sixgill sawshark, ''Pliotrema warreni'' is a sawshark of the family (biology), family Pristiophoridae. Presence of 6 pairs of gill slits highlights this genus among sharks; outside Hexanchiformes order, ''Pliotrema'' is the only shark with m ...

(''Pliotrema warreni'') of the South Indian ocean, which can grow up to and weigh . * Skates and allies (

Rajiformes Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head ...

)

:The largest and most diverse order of

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

' largest species is the

giant guitarfish The giant guitarfish (''Rhynchobatus djiddensis''), also known as the whitespotted wedgefish, is a large species of guitarfish in the family Rhinidae. It is restricted to the Red Sea, Persian Gulf, and western Indian Ocean, but was formerly con ...

(''Rhynchobatus djiddensis'') of the Red Sea and the eastern Indian ocean. The top size of the species is and . The largest of the skates is the

common skate The common skate (''Dipturus batis''), also known as the blue skate, is the largest skate in the world, attaining a length of up to .Griffiths AM, Sims DW, Cotterell SJ, El Nagar A, Ellis JR, Lynghammar A, McHugh M, Neat FC, Pade NG, Queiroz N, ...

(''Dipturus batis''). This species can grow up to in length and weigh . * Dogfish and allies (

Squaliformes The Squaliformes are an order (biology), order of sharks that includes about 126 species in seven families. Members of the order have two dorsal fins, which usually possess spines, they usually have a sharp head, no anal fin or nictitating me ...

) :The largest known member of this order is the

Greenland shark The Greenland shark (''Somniosus microcephalus''), also known as the gurry shark, grey shark, or by the Kalaallisut name ''eqalussuaq'', is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and southern s ...

(''Somniosus microcephalus''), a giant predator of sub-Arctic waters. This species has been confirmed to as much as in length and a weight of , although specimens of up to have been reportedly caught. The

Pacific sleeper shark The Pacific sleeper shark (''Somniosus pacificus'') is a sleeper shark of the family Somniosidae, found in the North Pacific on continental shelves and slopes in Arctic and temperate waters between latitudes 70°N and 22°N, from the surface t ...

(''Somniosus pacificus'') has been measured only to and in a gravid female, although specimens up to an estimated have been scientifically observed.Castro, José I., ''The Sharks of North America''. Oxford University Press (2011), The

spiny dogfish The spiny dogfish (''Squalus acanthias''), spurdog, mud shark, or piked dogfish is one of the best known species of the Squalidae (dogfish) family (biology), family of sharks, which is part of the Squaliformes order. While these common names ma ...

(''Squalus acanthias''), a very common species, reaches the largest sizes of the " true dogfish" family. Specimens have been measured at up to and . * Angelsharks ( Squatiniformes) :The largest of the bottom-dwelling angelsharks (named for their shape rather than disposition) is the common angelshark (''Squatina squatina'') of the northeast Atlantic ocean. This species can grow up to long and weigh more than . * Electric rays (

Torpediniformes Fernando de Buen y Lozano was a Spanish ichthyologist and oceanographer Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including e ...

) :The largest of the electric rays is

Atlantic torpedo The Atlantic torpedo (''Tetronarce nobiliana'') is a species of electric ray in the family Torpedinidae. It is found in the Atlantic Ocean, from Nova Scotia to Brazil in the west and from Scotland to West Africa and off southern Africa in the ea ...

(''Torpedo nobiliana''). This fish can measure long and weigh . However, a length of and weight of is more typical.Bester, C
Biological Profiles: Atlantic Torpedo
Florida Museum of Natural History Ichthyology Department. Retrieved on November 30, 2009. Females attain a larger size than males.

Spiny sharks (Acanthodii)

The largest of the now-extinct

Acanthodii Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes), typically considered a paraphyletic group. They are currently considered to represent a grade of various fish lineages leading up to the extant Chondrichthyes, which ...

was '' Xylacanthus grandis'', an ischnacanthiform based on a ~ long jaw bone. Based on the proportions of its relative ''

Ischnacanthus ''Ischnacanthus'' is an extinct genus of jawed fish in the class Acanthodii. It lived during the Early Devonian period, approximately 421–409 million years ago. It is known from a single species, which is also the type species, ''I. gracilis'' ...

'', ''X. grandis'' had an estimated total length of .

Bony fish (Osteichthyes)

Ray-finned fish (Actinopterygii)

Mola mola ocean sunfish Monterey Bay Aquarium 2

The largest living

( superclass

Osteichthyes Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilage ...

, which includes both

ray-finned Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

and lobe-finned fish) are the lesser known

southern sunfish The giant sunfish or bumphead sunfish (''Mola alexandrini''), also known as the Ramsay's sunfish, southern sunfish, southern ocean sunfish, short sunfish or bump-head sunfish in many parts of the world,Diane J. Bray, 2011, Short Sunfish, or even ...

(''Mola alexandrini'') followed by widely distributed and better known

ocean sunfish The ocean sunfish or common mola (''Mola mola'') is one of the largest bony fish in the world. It was misidentified as the heaviest bony fish, which was actually a different species, ''Mola alexandrini''. Adults typically weigh between . The spe ...

(''Mola mola'') and , both being members of the order

Tetraodontiformes The Tetraodontiformes are an order of highly derived ray-finned fish, also called the Plectognathi. Sometimes these are classified as a suborder of the order Perciformes. The Tetraodontiformes are represented by 10 extant families and at least ...

. The largest verified specimen belongs to the southern sunfish discovered dead near the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

in the Atlantic has set the record for being the largest extant bony fish with the weight of 2744 kg (6049 lb). The record size ocean sunfish crashed into a boat off Bird Island, Australia in 1910 and measured from fin-to-fin, in length and weighed about ,Wood, Gerald ''The Guinness Book of Animal Facts and Feats'' (1983) while the other record for the biggest bony fish is yet held by a''Mola alexandrini'' which was also coincidentally 2,300 kg in mass and 3.0 m in length, caught off in 1996 and misidentified as a ''Mola mola''.springer.com and new scientist.com As for length, the longest

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

bony fish on earth is the

giant oarfish The giant oarfish (''Regalecus glesne'') is a species of oarfish of the family Regalecidae. It is an oceanodromous species with a worldwide distribution, excluding polar regions. Other common names include Pacific oarfish, king of herrings, ribb ...

(''Regalecus glesne''). Slender and compressed, it averages over long at maturity. A specimen caught in 1885 of in length weighed . The longest known example, which was hit by a steamship, was measured as long. Much larger bony fish existed prehistorically, the largest ever known having been ''

Leedsichthys ''Leedsichthys'' is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic.Liston, JJ (2004). An overview of the pachycormiform ''Leedsichthys''. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - System ...

'' of the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period. This species is certainly the largest bony fish ever and perhaps the largest non-

marine animal to have ever existed. Estimates of the size of this fish range from and mass from 20 to 50 tons. A maximum size of and 25–30 tons has been deemed to be most realistic. * Sturgeons and paddlefishes (

Acipenseriformes Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest div ...

)

:The largest species is the

beluga sturgeon The beluga (), also known as the beluga sturgeon or great sturgeon (''Huso huso''), is a species of anadromous fish in the sturgeon family (Acipenseridae) of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, a ...

(''Huso huso'') of the Caspian and Black seas, the only extant bony fish to rival the massiveness of the ocean sunfish. The largest specimen considered reliable (based on remains) was caught in the

Volga The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

estuary in 1827 and measured and weighed . The slightly smaller

kaluga Kaluga ( rus, Калу́га, p=kɐˈɫuɡə), a city and the administrative center of Kaluga Oblast in Russia, stands on the Oka River southwest of Moscow. Population: Kaluga's most famous resident, the space travel pioneer Konstantin Tsiol ...

(''Huso dauricus'') or great Siberian sturgeon has been weighed reliably up to (Berg, 1932) and a length of . The North American

white sturgeon White sturgeon (''Acipenser transmontanus'') is a species of sturgeon in the family Acipenseridae of the order Acipenseriformes. They are an anadromous fish species ranging in the Eastern Pacific; from the Gulf of Alaska to Monterey, Californ ...

(''Acipenser transmontanus''), unverified to and ,

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, European oceanic, and the

Russian sturgeon The Russian sturgeon (''Acipenser gueldenstaedtii''), also known as the diamond sturgeon or Danube sturgeon, is a species of fish in the family Acipenseridae. It is found in Azerbaijan, Bulgaria, Georgia, Iran, Kazakhstan, Romania, Russia, Turkey ...

(''A. gueldenstaedtii''), at as much as and for a 75-year-old female, also can attain great sizes.

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

s and

Baikal sturgeon The Siberian sturgeon (''Acipenser baerii'') is a species of sturgeon in the family Acipenseridae. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian Seas, including the O ...

s are following as well. These fish are sometimes called the largest freshwater fish but sturgeons spend a great deal of time in

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

and switch back and forth between saltwater and freshwater environments in their life cycle. Also included in this order are the

paddlefish Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...

and the

Chinese paddlefish The Chinese paddlefish (''Psephurus gladius''; : literal translation: "white sturgeon"), also known as the Chinese swordfish, is an Extinction, extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. Wit ...

(''Psephurus gladius''), which is now officially recognised as extinct by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(as of July 2022), is also a very large fish. Reportedly, fisherman as recently as the 1950s have caught paddlefish measuring up to in total length, although no specimen greater than has been scientifically measured. The weight of the Chinese paddlefish is reportedly .Paxton & Eschmeyer (editors), ''Encyclopedia of Fishes, Second Edition''. Academic Press (1998), * Bonefish ( Albuliformes) :The largest ''Albuliformes'' is the

bonefish The bonefish (''Albula vulpes'') is the type species of the bonefish family (Albulidae), the only family in order Albuliformes. History Bonefish were once believed to be a single species with a global distribution, however 9 different species ...

(''Albula vulpes''), which weighs up to and measures up to long. It is silvery in color with dusky fins. The bases of the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s are yellow. * Bowfins (

Amiiformes The Amiiformes order of fish has only one extant species, the bowfin (''Amia calva''). These Amiiformes are found in the freshwater systems of North America, in the United States and parts of southern Canada. They live in freshwater streams, r ...

) :The

bowfin The bowfin (''Amia calva'') 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 the sole surviving species of the Halecomorphi ...

(''Amia calva'') is the sole member of its order. The most distinctive characteristic of the bowfin is its very long

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

consisting of 145 to 250 rays, and running from mid-back to the base of the tail. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is a single lobe, though heterocercal. They can grow up to in length, and weigh . * Eels (

Anguilliformes Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

)

:The largest species of "true eel," if measured in weight and overall bulk, is the

European conger The European conger (''Conger conger'') is a species of conger of the family Congridae. It is the heaviest eel in the world and native to the northeast Atlantic, including the Mediterranean Sea. Description and behavior European congers have an ...

(''Conger conger''). The maximum size of this species has been reported to and a mass of . Several

moray eel Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...

s can equal or exceed the previous eel in length but do not weigh as much. The longest fish in the order, at up to , is the

slender giant moray The slender giant moray or Gangetic moray, ''Strophidon sathete'', is the longest member of the family of moray eels. It is in the genus '' Strophidon''. The longest recorded specimen was caught in 1927, on the Maroochy River in Queensland; it m ...

(''Strophidon sathete'') of the Indo-Pacific oceans. * Silversides (

Atheriniformes The Atheriniformes, also known as the silversides, are an order (biology), order of ray-finned fishes that includes the Atherinidae, Old World silversides and several less-familiar families, including the unusual Phallostethidae. The order inclu ...

) :An order best known for its tiny representatives, the largest species is the jacksmelt ('' Atherinopsis californiensis'') of the Pacific Ocean. Although it reaches , it is not known to even reach . * Barreleyes, slickheads and argentines (

Argentiniformes The Argentiniformes are an order of ray-finned fish whose distinctness was recognized only fairly recently. In former times, they were included in the Osmeriformes (typical smelt and allies) as suborder Argentinoidei. That term refers only to ...

) :The largest species is the greater argentine ('' Argentina silus''), that has TL. :The largest barreleyes are javelin spookfish (''Bathylychnops exilis'')found in the northern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

and in the eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

near the

where it is found at depths of around . This species grows to a length of SL. * Jellynose fishes ( Ateleopodiformes) :The largest jellynose fishes is ''

Ateleopus ''Ateleopus'' is a genus of ray-finned fish in the jellynose family Ateleopodidae. It is the type genus of its family, and the order Ateleopodiformes. For some time, it was known as ''Podateles'', because ''Ateleopus'' had been used to repla ...

japonicus'' is an exception, retaining several fins as adults and having

ventral fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s that are located behind (not below) the pectoral fins.

Dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

s tend to be high, with a rather short base (9-13 rays, but in some as few as three); they are placed just behind the head. They have seven branchiostegal rays. The species have a range of sizes, the longest reaching . * Grinners (

Aulopiformes Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are someti ...

) :The largest member of this order is the

lancetfish Lancetfishes are large oceanic predatory fishes in the genus ''Alepisaurus'' ("scaleless lizard") in the monogeneric family Alepisauridae. Lancetfishes grow up to in length. Very little is known about their biology, though they are widely di ...

(''Alepisaurus ferox''), found in all the world's oceans. Slender, with a huge spine, these fish can reach long and can weigh up to . * Toadfish ( Batrachoidiformes) Batrachoides surinamensis

:The largest

toadfish Toadfish is the common name for a variety of species from several different families of fish, usually because of their toad-like appearance. "Dogfish" is a name for certain species along the gulf coast. Dolphin-Toadfish relationship Toadfish mak ...

is the Pacuma toadfish (''Batrachoides surinamensis''), reaching a size of up to and . * Flying-fish and allies (

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 (halfbeaks) ...

) :The largest member of this order, best known for its members' ability to

breach Breach, Breached, or The Breach may refer to: Places * Breach, Kent, United Kingdom * Breach, West Sussex, United Kingdom * ''The Breach'', Great South Bay in the State of New York People * Breach (DJ), an Electronic/House music act * Miroslava ...

the water and zip through the sky, is the pelagic

Houndfish The houndfish (''Tylosurus crocodilus'') is a game fish of the family (biology), family Belonidae. It is the largest member of its family, growing up to in length and in weight. It is also often called the crocodile needlefish. Description Whi ...

(''Tylosurus crocodilus''), a slender fish at up to and a weight of . The largest true "

flying fish The Exocoetidae are a family of marine fish in the order Beloniformes class Actinopterygii, known colloquially as flying fish or flying cod. About 64 species are grouped in seven to nine genera. While they cannot fly in the same way a bird do ...

" is the Japanese flying fish ('' Cheilopogon pinnatibarbatus japonicus''), which can range up to in length and weigh over . * Squirrelfish (

Beryciformes The Beryciformes are a poorly-understood order of carnivorous ray-finned fishes consisting of 7 families, 30 genera, and 161 species. They feed on small fish and invertebrates. Beyond this, little is known about the biology of most member speci ...

) :Best known for their highly

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

ous barbs, the

squirrelfish Holocentrinae is a subfamily of Holocentridae containing 40 recognized species and one proposed species. Its members are typically known as squirrelfish and all are nocturnal. All three genera in the subfamily are found in the Atlantic and ''Hol ...

's largest representative is the giant squirrelfish (''

Sargocentron spiniferum ''Sargocentron spiniferum'', common name sabre squirrelfish, giant squirrelfish and spiny squirrelfish, is a large Indo-Pacific species of squirrelfish belonging to the family Holocentridae. Description ''Sargocentron spiniferum'' is the larges ...

'') of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, at up to and . The slimmer ''

Holocentrus adscensionis ''Holocentrus adscensionis'' is a squirrelfish of the family Holocentridae found in the Atlantic Ocean. Its range extends from North Carolina, USA to Brazil and throughout the Caribbean Sea in the Western Atlantic and from Gabon Gabon (; ...

'' from warm parts of the Atlantic can reach even greater lengths of up to . * Whalefish (

Cetomimiformes The Cetomimiformes or whalefishes are an order of small, deep-sea ray-finned fish. Some authoritiesE.g. Nelson (2006) include the whalefishes as part of the order Stephanoberyciformes, within the superfamily Cetomimoidea. Their sister order, the ...

) :Known for flesh that feels flabby to the touch, this order reaches largest sizes in the

flabby whalefish Cetomimidae is a family of small, deep-sea cetomimiform fish. They are among the most deep-living fish known, with some species recorded at depths in excess of . Adults are known as flabby whalefishes while juveniles are known as tapetails and ...

(''Gyrinomimus grahami'') of all southern oceans. This species, which can range up to in length and weigh , is sometimes commercially fished. * Characins (

Characiformes Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras.; Buckup P.A.: "Relationshi ...

) :The largest species is the African freshwater fish, the giant tigerfish (''Hydrocynus goliath''). The top size of this fish is and . Among the largest of the

characin Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras.; Buckup P.A.: "Relationshi ...

family is the popular sport-fish, the

golden dorado ''Salminus brasiliensis'' (dourado, dorado, golden dorado, river tiger or jaw characin) is a large, predatory characiform freshwater fish found in central and east-central South America. Despite having ''Salminus'' in its name, the dorado is not r ...

(''Salminus brasiliensis''), which can reach up to in length and weigh . Among the characins are the infamous neotropical

piranha A piranha or piraña (, , or ; or , ) is one of a number of freshwater fish in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, ...

s. Carnivorous species can grow up to , although the

Tambaqui The tambaqui (''Colossoma macropomum'') is a large species of freshwater fish in the family Serrasalmidae. It is native to tropical South America, but kept in aquaculture and introduced elsewhere. It is also known by the names black pacu, blac ...

(''Colossoma macropomum''), at up to and , is often considered a giant, herbivorous form of piranha. * Herring (

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

) :The largest

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, i ...

is probably the Dorab wolf herring (''

Chirocentrus The wolf herrings are a family (Chirocentridae) of two marine species of ray-finned fish related to the herrings. Both species have elongated bodies and jaws with long sharp teeth that facilitate their ravenous appetites, mostly for other fish. ...

dorab'') of the Indo-Pacific oceans. The maximum size of this species has been reported as much as , but these slender fish have never been recorded as exceeding in weight. The so-called "king of herrings" is not a herring, but an

oarfish Oarfish are huge, greatly elongated, pelagic lampriform fish belonging to the small family Regalecidae. Found in areas spanning from temperate ocean zones to tropical ones, yet rarely seen, the oarfish family contains three species in two gene ...

. * Minnows and allies (

Cypriniformes Cypriniformes is an order of ray-finned fish, including the carps, minnows, loaches, and relatives. Cypriniformes is an Order within the Superorder Ostariophysi consisting of "Carp-like" Ostariophysins. This order contains 11-12 families, ...

) :The minnow family (which includes carp),

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

, is the largest family of vertebrates, with over 2400 species known today. The largest species is the

giant barb The giant barb, Siamese giant carp, or simply Siamese carp (''Catlocarpio siamensis'') ( km, ត្រីគល់រាំង, ; th, กระโห้, , , or , , ; Vietnamese: ''cá Hô''), is the largest species of cyprinid in the world. Thes ...

(''Catlocarpio siamensis''), which is endemic to three river basins in southeast Asia and reaches a size of as much as and a weight of as much as . In centuries past,

mahseer Mahseer is the common name used for the genera ''Tor'', ''Neolissochilus'', '' Naziritor'' and '' Parator'' in the family Cyprinidae (carps). The name is, however, more often restricted to members of the genus ''Tor''.Sen TK, Jayaram KC, 1982. Th ...

, specifically the

golden mahseer ''Tor putitora'', the Putitor mahseer, Himalayan mahseer, or golden mahseer, is an endangered species of cyprinid fish that is found in rapid streams, riverine pools, and lakes in the Himalayan region. Its native range is within the basins of th ...

(''Tor putitora'') of Southern Asia was reported to reach similar lengths, but the species has been overfished and specimens nearly as large as the giant barb have not been reported in recent centuries. *Pikes and allies (

Esociformes The Esociformes () are a small order of ray-finned fish, with two families, Umbridae and Esocidae. The pikes of genus '' Esox'' give the order its name. This order is closely related to the Salmoniformes, the two comprising the superorder Prot ...

) :The largest species in this small but interesting order (formerly allied with the

salmonids Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefi ...

) is the

muskellunge The muskellunge ''(Esox masquinongy)'', often shortened to muskie, musky or lunge is a species of large freshwater predatory fish native to North America. It is the largest member of the pike family, Esocidae. Origin of name The name "muskellun ...

(''Esox masquinongy'') of the rivers of North America. These predatory fish can grow up to and . * Killifish and allies (

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 ...

) :The largest species in this relatively small-bodied order is the Pacific four-eyed fish ('' Anableps dowei''), reaching a size of and . *Ladyfish and allies (

Elopiformes The Elopiformes are the order of ray-finned fish including the tarpons, tenpounders, and ladyfish, as well as a number of extinct types. They have a long fossil record, easily distinguished from other fishes by the presence of an additional set ...

) :This small order is usually considered closely related to the true eels although its members are very different in appearance and behavior from eels. The largest species is much-coveted-sport fish, the

Atlantic tarpon The Atlantic tarpon (''Megalops atlanticus'') is a ray-finned fish that inhabits coastal waters, estuaries, lagoons, and rivers. It is also known as the silver king. It is found in the Atlantic Ocean, typically in tropical and subtropical regions ...

(''Megalops atlanticus''). The maximum recorded size for this species is and length is up to . * Cod (

Gadiformes Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in temper ...

)

:The

Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.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 s ...

) :The largest form of stickleback, a small, cylindric type of fish, is the sea stickleback or fifteenspine stickleback (''Spinachia spinachia''). This species can range up to in length and weigh up to . * Clingfish (

Gobiesociformes Clingfishes are fishes of the family Gobiesocidae, the only family in the order Gobiesociformes. These fairly small to very small fishes are widespread in tropical and temperate regions, mostly near the coast, but a few species in deeper seas or ...

) :These bottom-dwelling fish reach their maximum size in ''

Sicyases sanguineus ''Sicyases sanguineus'' is a species of amphibious marine clingfish in the family Gobiesocidae. It lives in the Southeast Pacific along the entire coast of Chile and southern Peru. Locally, it is known as ' (literally, frog-fish). It inhabits sh ...

''. This species can reach in length and weigh up to . * Shellears and allies (

Gonorynchiformes The Gonorynchiformes are an order of ray-finned fish that includes the important food source, the milkfish (''Chanos chanos'', family Chanidae), and a number of lesser-known types, both marine and freshwater. The alternate spelling "Gonorhyn ...

) :The well-known

milkfish The milkfish (''Chanos chanos'') is the sole living species in the family Chanidae. However, there are at least five extinct genera from the Cretaceous. The repeating scientific name (tautonym) is from Greek ( ‘mouth’). The species has many ...

(''Chanos chanos'') is the largest member of this order. The maximum size is and long. * Knifefish (

Gymnotiformes The Gymnotiformes are an order of teleost bony fishes commonly known as Neotropical knifefish or South American knifefish. They have long bodies and swim using undulations of their elongated anal fin. Found almost exclusively in fresh water (the ...

) :The largest knifefish is the

electric eel The electric eels are a genus, ''Electrophorus'', of neotropical freshwater fish from South America in the family Gymnotidae. They are known for their ability to stun their prey by generating electricity, delivering shocks at up to 860 volts ...

(''Electrophorus electricus'') The electric eel has an elongated,

cylindrical A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infini ...

body, typically growing to about in length, and in weight, making it the largest species of the

. * Mooneyes (

Hiodontiformes Hiodontiformes is an order of ray-finned fish consisting of the two living species of the mooneye family, Hiodontidae, and three extinct genera. These are traditionally classified within the order Osteoglossiformes, a placement some authorit ...

) :Only two extant species are known to exist in this relatively new order. The larger of the two is the

goldeye The goldeye (''Hiodon alosoides'') is a freshwater fish found in Canada and the northern United States. It is one of only two extant species in the family Hiodontidae, the other species being ''Hiodon tergisus''. The species name ''alosoides'' ...

(''Hiodon alosoides'') from the northern rivers of North America, which can reach up to in length and can weigh . * Ribbonfish and allies (

Lampriformes Lampriformes is an order of ray-finned fish. Members are collectively called lamprids (which is more properly used for the Lampridae) or lampriforms, and unite such open-ocean and partially deep-sea Teleostei as the crestfishes, oarfish, opah ...

) :The largest member of this small but fascinating order is the aforementioned

king of herrings The giant oarfish (''Regalecus glesne'') is a species of oarfish of the family Regalecidae. It is an oceanodromous species with a worldwide distribution, excluding polar regions. Other common names include Pacific oarfish, king of herrings, ribbo ...

or oarfish (''Regalecus glesne''), the longest extant

on earth. Another interesting big fish in this order is the

opah Opahs, also commonly known as moonfish, sunfish (not to be confused with Molidae), kingfish, redfin ocean pan are large, colorful, deep-bodied pelagic lampriform fishes comprising the small family Lampridae (also spelled Lamprididae). The famil ...

(''Lampris guttatus''), which as opposed to the king of herrings, is massive and has a chunky, rounded shape. Opahs can range up to in length and weigh up to . * Gars ( Lepisosteiformes)

:The largest of the gar, and the largest entirely freshwater fish in North America, is the

alligator gar The alligator gar (''Atractosteus spatula'') is a ray-finned euryhaline fish related to the bowfin in the infraclass Holostei . It is the largest species in the gar family, and among the largest freshwater fish in North America. The fossil reco ...

(''Atractosteus spatula''). The largest gar ever known, caught in

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...

in 1925, was in length and weighed . * Anglerfish (

Lophiiformes The anglerfish are fish of the teleost order Lophiiformes (). They are bony fish named for their characteristic mode of predation, in which a modified luminescent fin ray (the esca or illicium) acts as a lure for other fish. The luminescence c ...

) :The largest of this diverse order is the common goosefish (''

Lophius piscatorius ''Lophius piscatorius'', commonly known as the angler, European angler or common monkfish, is a monkfish in the family Lophiidae. It is found in coastal waters of the northeast Atlantic, from the Barents Sea to the Strait of Gibraltar, the Medit ...

'') found in the northeastern Atlantic off Europe and North Africa. This big-mouthed fish can attain a size of and a length of . * Lanternfish (

Myctophiformes The Myctophiformes are an order of ray-finned fishes consisting of two families of deep-sea marine fish, most notably the highly abundant lanternfishes (Myctophidae). The blackchins (Neoscopelidae) contain six species in three genera, while t ...

) :The largest of the numerous but small

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

is Bolin's lanternfish ('' Gymnoscopelus bolini'') of the Indo-Pacific oceans, at up to and . * Mullets (

Mugiliformes The mullets or grey mullets are a family (Mugilidae) of ray-finned fish found worldwide in coastal temperate and tropical waters, and some species in fresh water. Mullets have served as an important source of food in Mediterranean Europe since R ...

) :The largest of mullets

flathead mullet The flathead grey mullet (''Mugil cephalus'') is an important food fish species in the mullet family Mugilidae. It is found in coastal tropical and subtropical waters worldwide. Its length is typically . It is known with numerous English names, ...

(''Mugil cephalus'') have dark centers which give the appearance of a series (6-7) of dark horizontal stripes. The fish grow to lengths up to with weights as high as . * Pearlfish and allies (

Ophidiiformes Ophidiiformes is an order of ray-finned fish that includes the cusk-eels (family Ophidiidae), pearlfishes (family Carapidae), viviparous brotulas (family Bythitidae), and others. Members of this order have small heads and long slender bodies. Th ...

) :The largest member of this order is the widely distributed giant

cusk-eels The cusk-eel family, Ophidiidae, is a group of marine bony fishes in the Ophidiiformes order. The scientific name is from the Greek ''ophis'' meaning "snake", and refers to their eel-like appearance. True eels, however, diverged from other ray-fi ...

(''

Lamprogrammus ''Lamprogrammus'' is a genus of cusk-eels. Species There are currently five recognized species in this genus: * '' Lamprogrammus brunswigi'' ( A. B. Brauer, 1906) * '' Lamprogrammus exutus'' Nybelin & Poll, 1958 (Legless cuskeel) * '' Lamprogra ...

shcherbachevi''). A cuskeel can be nearly long, but even large fish probably aren't much over since they are quite slender. * Smelts and allies (

Osmeriformes 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 Protacanthopte ...

) :The largest smelt is the

rainbow smelt The rainbow smelt (''Osmerus mordax'') is a North American species of fish of the family Osmeridae. Walleye, trout, and other larger fish prey on these smelt. The rainbow smelt prefer juvenile ciscoes, zooplankton such as calanoid copepods ('' L ...

(''Osmerus mordax''). The body of the rainbow smelt is slender and cylindrical. When full grown, the rainbow smelt is between long and weighs about . Individuals over long are known. * Bony-tongued fish (

Osteoglossiformes Osteoglossiformes (Greek: "bony tongues") is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South ...

) :The largest species is the South American fish usually known as the

arapaima The arapaima, pirarucu, or paiche is any large species of bonytongue in the genus ''Arapaima'' native to the Amazon and Essequibo basins of South America. ''Arapaima'' is the type genus of the subfamily Arapaiminae within the family Osteoglossi ...

(''Arapaima gigas''). The maximum size this species can attain is a matter of some controversy and some rank it among the world's largest freshwater fishes. No individual arapaima over has been verified and measured. The skeleton of a fish reported to have been measured by native hunters as and weighing when caught, was later examined as a skeleton scientifically and was found to have been roughly within that outsized dimension. * Perches and allies (

Perciformes Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...

)

:The title of the largest member of this order, the most numerous order of all vertebrates, is a matter of some debate. A large

marlin Marlins are fish from the family Istiophoridae, which includes about 10 species. A marlin has an elongated body, a spear-like snout or bill, and a long, rigid dorsal fin which extends forward to form a crest. Its common name is thought to deri ...

is the biggest of these fishes: the

black marlin The black marlin (''Istiompax indica'') is a species of marlin found in tropical and subtropical areas of the Indian and Pacific Oceans. With a maximum published length of and weight of , it is one of the largest marlins and also one of the la ...

(''Makaira indica'') of the Indo-Pacific, the

Atlantic blue marlin The Atlantic blue marlin (''Makaira nigricans'') is a species of marlin endemic to the Atlantic Ocean. It is closely related to, and usually considered conspecific with, the Indo-Pacific blue marlin, then simply called blue marlin. Some authori ...

(''Makaira nigricans'') and the

Indo-Pacific blue marlin The Indo-Pacific blue marlin (''Makaira mazara'') is a species of marlin belonging to the family Istiophoridae. Taxonomy ''Makaira mazara'' is closely related to, and usually considered conspecific with, the Atlantic blue marlin, then simply ca ...

(''Makaira mazara''). All of these similarly sized species can exceptionally reach up to in length and weight may be as much as or even . Another notable giant of the perch order is the

Atlantic bluefin tuna The Atlantic bluefin tuna (''Thunnus thynnus'') is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna (mainly when including Pacific bluefin as a subspecies), giant bluefin tuna or individuals exceed ...

(''Thunnus thynnus'') of the Northern Atlantic ocean, which has been verified at up to and , although can reportedly reach .Burnie D and Wilson DE (Eds.), ''Animal: The Definitive Visual Guide to the World's Wildlife''. DK Adult (2005), The

swordfish Swordfish (''Xiphias gladius''), also known as broadbills in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfis ...

(''Xiphias gladius'') can reach a maximum weight of and length of . Due to heavy fishing of both species, swordfish and tuna of great sizes are increasingly rare. One of the largest freshwater fishes is the

Nile perch The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is wid ...

(''Lates niloticus''), which grows up to and . The biggest of snappers is the

Cubera snapper The cubera snapper (''Lutjanus cyanopterus''), also known as the Cuban snapper, is a species of marine ray-finned fish, a snapper belonging to the family Lutjanidae. It is native to the western Atlantic Ocean. It is a commercially important spec ...

(''Lutjanus cyanopterus'') of the Caribbean sea and east coast of South America, at a maximum size of and in length. The largest species of grunt is the white margate (''Haemulon album'') of the Caribbean sea and east coast of South America, at up to and in length. The

blennies Blenny (from the Greek and , mucus, slime) 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 ...

can range up to in the hairtail blenny ('' Xiphasia setifer'') of the Indo-Pacific. The jacks or mackerels reach their maximum size in the

narrow-barred Spanish mackerel The narrow-barred Spanish mackerel (''Scomberomorus commerson'') is a mackerel of the family Scombridae found in a wide-ranging area in Southeast Asia, but as far west as the east coast of Africa and from the Middle East and along the northern coa ...

(''Scomberomorus commerson''), which can attain and . The largest

butterflyfish The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the Atlant ...

are either the

lined butterflyfish The lined butterflyfish (''Chaetodon lineolatus'') is a species of marine ray-finned fish. a butterflyfish belonging to the family Chaetodontidae, one of the largest species in the genus ''Chaetodon''. It has a wide range from the Red Sea to Sou ...

(''Chaetodon lineolatus'') or the

saddle butterflyfish The saddle butterflyfish (''Chaetodon ephippium'') is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the Indian and Pacific Oceans from Sri Lanka and the Cocos-Keeling Islands to the ...

(''C. ephippium''), both of the Indo-Pacific and both of which can measure up to . The freckled darter (''Percina lenticula'') of the United States, the biggest of the

darters The darters, anhingas, or snakebirds are mainly tropical waterbirds in the family Anhingidae, which contains a single genus, ''Anhinga''. There are four living species, three of which are very common and widespread while the fourth is rarer and ...

, reaching and . The largest

drum The drum is a member of the percussion group of musical instruments. In the Hornbostel-Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a she ...

is the

Totoaba The totoaba or totuava (''Totoaba macdonaldi'') is a species of marine fish, a very large member of the drum family Sciaenidae that is endemic to the Gulf of California in Mexico. It is the only species in the genus ''Totoaba''. Formerly abundan ...

(''Totoaba macdonaldi'') of the Gulf of California, at up to and long. Among the sea bass or groupers, many of which can grow quite large, the greatest size are reached in the

Atlantic goliath grouper The Atlantic goliath grouper or itajara (''Epinephelus itajara''), formerly known as the jewfish, is a saltwater fish of the grouper family and one of the largest species of bony fish. The species can be found in the west ranging from northeaste ...

(''Epinephelus itajara'') and the

giant grouper The giant grouper (''Epinephelus lanceolatus''), also known as the Queensland grouper, brindle grouper or mottled-brown sea bass, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serr ...

(''Epinephelus lanceolatus''). Both can reach a maximum known length of and weight of and respectively. The species-rich

cichlids Cichlids are fish from the family (biology), family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have c ...

reach their maximum size in the

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

giant cichlid The giant cichlid (''Boulengerochromis microlepis''), also known as the emperor cichlid, is a species of fish in the family Cichlidae, endemic to Lake Tanganyika in Africa.humphead wrasse The humphead wrasse (''Cheilinus undulatus'') is a large species of wrasse mainly found on coral reefs in the Indo-Pacific region. It is also known as the Māori wrasse, Napoleon wrasse, Napoleon fish, Napoleonfish, ''so mei'' 蘇眉 (Cantonese), ...

(''Cheilinus undulatus'') of the Indo-Pacific's coral reefs is by far the largest

wrasse The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them le ...

, and it can reach a maximum size of and . Among a fairly small-bodied family, the damselfishes, the

Garibaldi Giuseppe Maria Garibaldi ( , ;In his native Ligurian language, he is known as ''Gioxeppe Gaibado''. In his particular Niçard dialect of Ligurian, he was known as ''Jousé'' or ''Josep''. 4 July 1807 – 2 June 1882) was an Italian general, patr ...

(''Hypsypops rubicundus'') of the Pacific coast of America is the biggest, reaching up to and . The marbled sleeper (''Oxyeleotris marmorata'') of East Asia is the largest member of the family or sub-order that almost certain contains the smallest living vertebrate, and can reach long and weigh . * Trout-perch and allies (

Percopsiformes The Percopsiformes are a small order of ray-finned fishes, comprising the trout-perch and its allies. It contains just ten extant species, grouped into seven genera and three families. Five of these genera are monotypic In biology, a mono ...

) :The largest species in this small order (both by number of species and body size) is the

sand roller ''Percopsis transmontana'', the sand roller, is a species of percopsiform fish endemic to the Columbia River drainage in the northwestern United States. This species grows to a length of TL. Sand rollers can live up to 6 years in slow-moving ...

(''Percopsis transmontana'') of North America. This species can range up to in length and can weigh over . * Flatfish (

Pleuronectiformes A flatfish is a member of the ray-finned demersal fish order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migratin ...

)

:The largest of the well-known and heavily fished flatfish is the

Pacific halibut The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

(''Hippoglossus stenolepis''). This giant can reach and , although fish even approaching this size would be extraordinary these days. The

Atlantic halibut The Atlantic halibut (''Hippoglossus hippoglossus'') is a flatfish of the family Pleuronectidae. They are demersal fish living on or near sand, gravel or clay bottoms at depths of between . The halibut is among the largest Teleostei, teleost (bon ...

(''Hippoglossus hippoglossus'') is also sometimes titled the largest flatfish, although it has a slightly smaller maximum size, at and . * Beardfish (

Polymixiiformes The beardfishes consist of a single extant genus, '' Polymixia'', of deep-sea marine ray-finned fish named for their pair of long hyoid barbels. They are classified in their own order Polymixiiformes . But as Nelson says, "few groups have been s ...

) :The little-known beardfish are sometimes classified with the

. The largest beardfish is ''Polymixia busakhini'' of the Indo-Pacific, which can range up to in length. * Polypterids and allies (

Polypteriformes Bichirs and the reedfish comprise Polypteridae , a family of archaic ray-finned fishes and the only family in the order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The Diversity of Fishes. West Sussex, UK: Blackwell Pub ...

) :The largest polypterid is ''

Polypterus congicus ''Polypterus congicus'', the Congo bichir, is a species of bichir with a maximum recorded size of . The colour also varies from yellowish brown to grey, darker in the top, paler in the ventral area. It has a pattern of around 8 irregular vertical ...

'', which reaches up to in length. * Gulper eels (

Saccopharyngiformes The saccopharyngiformes are a derived lineage of unusual eels within the order Anguilliformes, and includes families Cyematidae, Monognathidae, Eurypharyngidae, Saccopharyngidae, and the proposed family Neocyematidae. Most of the fish in this gro ...

) :The largest gulper eel is the

pelican eel The pelican eel (''Eurypharynx pelecanoides'') is a deep-sea eel. It is the only known member of the genus ''Eurypharynx'' and the family Eurypharyngidae. It belongs to the "saccopharyngiforms", members of which were historically placed in their ...

(''Eurypharynx pelecanoides''). The pelican eel grows to about in length. * Salmon and allies (

Salmoniformes Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

)

:The largest species of salmonid is the

taimen Siberian taimen (''Hucho taimen''), also known as the common taimen (russian: Обыкнове́нный тайме́нь, Obyknovénnyĭ taĭménʹ), Siberian giant trout or Siberian salmon, is a species of salmon-like ray-finned fish from the ...

(''Hucho taimen''). The biggest recorded taimen was caught in the Kotui River in

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, and measured and weighed . Some sources claim the largest is the

Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus ''Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ve ...

(''Oncorhynchus tshawytscha'') of America's Pacific Northwest, although this species falls behind the taimen in maximum size. The maximum size of this fish is and long. * Sculpins (

Scorpaeniformes The Scorpaeniformes are a diverse order of 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 species, with over 1,320. They are ...

) :Although less venomous than many smaller fish in the same order, the

skilfish The skilfish (''Erilepis zonifer'') is a species of ray-finned fish, one of two species belonging to the family Anoplopomatidae and the only species in the genus ''Erilepis''. It is also known as black cod, though they have no relation to cod, ...

(''Erilepis zonifer'') of the North Pacific, is largest

sculpin A sculpin is a type of fish that belongs to the superfamily Cottoidea in the order Scorpaeniformes.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology suggest transitions in station-holding demand a ...

. The maximum size is and the weight can be up to . The

Lingcod The lingcod or ling cod (''Ophiodon elongatus''), also known as the buffalo cod or cultus cod, is a fish of the greenling family Hexagrammidae. It is the only extant member of the genus ''Ophiodon. ''A slightly larger, extinct species, '' Ophi ...

(''Ophiodon elongatus'') of the west coast of North America is sometimes listed as the largest sculpin but it is not known to exceed in length or in weight. The

Cottidae The Cottidae are a family of fish in the superfamily Cottoidea, the sculpins. It is the largest sculpin family, with about 275 species in 70 genera.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology ...

can range up to and in the

cabezon Cabezón is the Spanish word for "stubborn" or "big-headed". In Chile, cabezon means intelligent. Cabezon or cabezón may refer to: Fish species * Cabezon (fish) (''Scorpaenichthys marmoratus''), a species of fish in the family Cottidae * '' Cach ...

(''Scorpaenicthys marmoratus'') of coastal North America. * Catfish (

Siluriformes Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of Actinopterygii, ray-finned fish. Named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, catfish range in size and behavior from ...

) :Most authorities now give the crown of the largest

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

to the

Mekong giant catfish The Mekong giant catfish (''Pangasianodon gigas''; th, ปลาบึก, , ; km, ត្រីរាជ /''trəy riec''/; vi, cá tra dầu), is a large, threatened species of catfish (order Siluriformes) in the shark catfish family (Pang ...

, ''Pangasianodon gigas'', which is also considered the heaviest completely freshwater fish. This fish has been recorded at sizes up to and .Fish whopper: 646 pounds a freshwater record
NBC News (2005-07-01)Seth Mydans
Hunt for the big fish becomes a race
International Herald Tribune (2005-08-25) The closely-related Asian

giant pangasius The giant pangasius, paroon shark, pangasid-catfish or Chao Phraya giant catfish (''Pangasius sanitwongsei'') is a species of freshwater fish in the shark catfish family (Pangasiidae) of order Siluriformes, found in the Chao Phraya and Mekong b ...

(''Pangasius sanitwongsei'') can grow to and . Another large species is the

wels catfish The wels catfish ( or ; ''Silurus glanis''), also called sheatfish or just wels, is a large species of catfish native to wide areas of central, southern, and eastern Europe, in the basins of the Baltic, Black and Caspian Seas. It has been introd ...

(''Silurus glanis'') of Europe and Central Asia, which strongly rivals the proceeding species in weight and could possibly surpass them in length. While wels have been confirmed to , other whiskered giants have been reliably reported to grow to and and less reliably to . In South America there also exists the '' Brachyplatystoma filamentosum'', which can reportedly reach up to and . * Ridgeheads and allies (

Stephanoberyciformes The Stephanoberyciformes are an order of marine ray-finned fishes, consisting of about 68 species, the majority (61) of which belong to the ridgehead family (Melamphaidae). The Stephanoberyciformes are mostly uncommon deep-sea species with little ...

) :The largest ridgeheads ''

Poromitra curilensis ''Poromitra'' is a genus of ridgeheads. The 22 known species of Poromitra have been divided into five species groups according to variation in preopercle anatomy. A Poromitra curilensis specimen from the Shirshov Institute of Oceanology, obta ...

'', a Pacific ridgehead related to the crested bigscale, at up to 18 centimetres standard length (SL; a measurement excluding the caudal fin). Most ridgeheads are well under 10 centimetres SL. * Bristlemouths (

Stomiiformes Stomiiformes is an order of deep-sea ray-finned fishes of very diverse morphology. It includes, for example, dragonfishes, lightfishes (Gonostomatidae and Phosichthyidae), loosejaws, marine hatchetfishes and viperfishes. The order contains 4 ...

)

:The largest of the deep-sea

bristlemouth The Gonostomatidae are a family of mesopelagic marine fish, commonly named bristlemouths, lightfishes, or anglemouths. It is a relatively small family, containing only eight known genera and 32 species. However, bristlemouths make up for their ...

s is the short-tailed barbeled dragonfish ('' Oppostomias micripnus''). The top size of a female of this species is probably over and long. In species like the barbeled dragonfish (''

Idiacanthus atlanticus ''Idiacanthus atlanticus'', the black dragonfish, is a barbeled dragonfish of the family Stomiidae, found circumglobally in southern subtropical and temperate oceans between latitudes 25°S and 60°S, at depths down to . The species is sexually ...

''), the snake-like females can measure up to long, about 50 times as long as the male. Although ''

Idiacanthus ''Idiacanthus'' is a genus of barbeled dragonfishes, the larvae of which are noted for exhibiting the Stylophthalmine trait. Species There are currently three recognized species in this genus: * '' Idiacanthus antrostomus'' C. H. Gilbert, 1890 ...

'' is much more slender and is lighter than '' Oppostomias''. * Swamp-eels (

Synbranchiformes Synbranchiformes, often called swamp eels, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii. Taxonomy No synbrachiform fossil is known. The Mastacembeloidei were ...

) :The tropic-dwelling swamp-eels, which are not closely related to true eels, reaches their largest size in the marbled swamp eel (''Synbrachus marmoratus'') of Central and South America. This fish can range up to and weigh . * Seahorses and allies (

Syngnathiformes The Syngnathiformes are an order of ray-finned fishes that includes the trumpetfishes and seahorses.FishBase (2005)Order Summary for Syngnathiformes Version of 2005-FEB-15. Retrieved 19 Aug 2008. These fishes have elongated, narrow, bodies sur ...

) :The largest of this diverse order is the red cornetfish (''Fistularia petimba''), a long, thin species found in all tropical oceans. This fish can reach a length of and a weight of . The largest of the famous, petite

seahorse A seahorse (also written ''sea-horse'' and ''sea horse'') is any of 46 species of small marine fish in the genus ''Hippocampus''. "Hippocampus" comes from the Ancient Greek (), itself from () meaning "horse" and () meaning "sea monster" or " ...

s is the

big-belly seahorse The big-belly seahorse (''Hippocampus abdominalis'') or pot-bellied seahorse is one of the largest seahorse species in the world, with a length of up to , and is the largest in Australia. Seahorses are members of the family Syngnathidae, and are ...

(''Hippocampus abdominalis'') found off Australia and New Zealand, which can grow to high and weigh over . * Pufferfishes and allies (

) :The

starry pufferfish Starry may refer to: * ''Starry'' (The Killjoys album), 1994 *Starry (Purr Machine album) *Donn A. Starry (1925–2011), United States Army general *Starry Lee (born 1974), Hong Kong politician *Starry Internet, a fixed wireless ISP service See a ...

Arothron stellatus ''Arothron stellatus'', also known as the stellate puffer, starry puffer, starry pufferfish, or starry toadfish, is a demersal marine fish belonging to the family Tetraodontidae. It is found in shallow water in the Indo-Pacific region. Desc ...

is the largest pufferfish in the world, growing to a length of . The largest freshwater pufferfish is the

mbu pufferfish The Mbu pufferfish, also known as Mbuna pufferfish, giant pufferfish, or giant freshwater pufferfish (''Tetraodon mbu''), is a carnivorous freshwater pufferfish originating from the middle and lower sections of the Congo river in Africa, as wel ...

(''Tetraodon mbu'') from the

Congo river The Congo River ( kg, Nzâdi Kôngo, french: Fleuve Congo, pt, Rio Congo), formerly also known as the Zaire River, is the second longest river in Africa, shorter only than the Nile, as well as the second largest river in the world by discharge ...

basin. It attains lengths of . As such, these fish are difficult to adequately house in captivity since they require a very large

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

and appropriately scaled

water filtration A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation ...

. At lengths up to , the

stone triggerfish The stone triggerfish (''Pseudobalistes naufragium'') is the largest species of triggerfish. Distribution It is found at reefs and over sandy bottoms in the east Pacific, ranging from Baja California (Mexico) to Chile Chile, officially ...

("Pseudobalistes naufragium") from the eastern Pacific is the largest triggerfish, edging out the

titan triggerfish The titan triggerfish, giant triggerfish or moustache triggerfish (''Balistoides viridescens'') is a large species of triggerfish found in lagoons and at reefs to depths of in most of the Indo-Pacific, though it is absent from Hawaii. With a len ...

(''Balistoides viridescens''). * Dories (

Zeiformes The Zeiformes are a small order of marine ray-finned fishes most notable for the dories, a group of common food fish. The order consists of about 33 species in seven families, mostly deep-sea types. Zeiform bodies are usually thin and deep. Mo ...

) :The largest species of dory is the Cape dory (''

Zeus capensis The Cape dory, Cape Dory, or Cape John Dory (''Zeus capensis'') is a fish of the family Zeidae. It occurs on the coast of Namibia, South Africa, and Mozambique in South Atlantic and Western Indian Oceans. It is a demersal fish that lives at the ...

'') reaching a size of and a weight of .

Lobe-finned fish (Sarcopterygii)

The largest living

lobe-finned fish Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass includi ...

is the

coelacanth The coelacanths ( ) are fish belonging to the order Actinistia that includes two extant species in the genus ''Latimeria'': the West Indian Ocean coelacanth (''Latimeria chalumnae''), primarily found near the Comoro Islands off the east coast ...

. The average weight of the living

West Indian Ocean coelacanth The West Indian Ocean coelacanth (''Latimeria chalumnae'') (sometimes known as gombessa, African coelacanth, or simply coelacanth) is a crossopterygian, one of two extant species of coelacanth, a rare order of vertebrates more closely related to ...

, (''Latimeria chalumnae''), is , and they can reach up to in length. Specimens can weigh up to . The largest lobe-finned fish of all time was ''

Rhizodus ''Rhizodus'' (root tooth) is an extinct genus of basal, finned tetrapodomorphs (the group of sarcopterygians that contains modern tetrapods and their extinct relatives). It belonged to Rhizodontida, one of the earliest-diverging tetrapodomorph c ...

'' at up to . * Lungfish (

Dipnoi Lungfish are freshwater vertebrates belonging to the order Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, i ...

) :The largest lungfish, the

African lungfish ''Protopterus'' is the genus of four species of lungfish found in Africa. ''Protopterus'' was formerly thought to be the sole genus in the family Protopteridae, but more recent studies have classified it with ''Lepidosiren'' in the family Lepid ...

(''Protopterus aethiopicus''), is smooth, elongated, and cylindrical with deeply embedded

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

. The tail is very long and tapers at the end. They can reach a length of up to and may weigh as much as .Protopterus aethiopicus
. Fishing-worldrecords.com The pectoral and pelvic fins are also very long and thin, almost spaghetti-like.

References

{{diversity of fish

Lists of fishes Heaviest or most massive organisms

Largest extant fish

Jawless fish (Agnatha)

Armored fish (Placodermi)

Cartilaginous fish (Chondrichthyes)

Spiny sharks (Acanthodii)

Bony fish (Osteichthyes)

Ray-finned fish (Actinopterygii)

Lobe-finned fish (Sarcopterygii)

See also

References