The Tetraodontiformes are an order of highly derived

ray-finned fish 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 h ...

, also called the Plectognathi. Sometimes these are classified as a suborder of the order

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 Tetraodontiformes are represented by 10 extant

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...

and at least 349

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

overall; most are marine and dwell in and around tropical

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

s, but a few species are found in freshwater streams and

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

. They have no close relatives, and descend from a line of

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

-dwelling species that emerged around 80 million years ago.

Description

Various bizarre forms are included here, all radical departures from the streamlined body plan typical of most fishes. These forms range from nearly square or triangular (

boxfish Ostraciidae is a family of squared, bony fish belonging to the order Tetraodontiformes, closely related to the pufferfishes and filefishes. Fish in the family are known variously as boxfishes, cofferfishes, cowfishes and trunkfishes. It contains ...

es), globose ( pufferfishes) to laterally compressed ( filefishes and

triggerfish Triggerfish are about 40 species of often brightly colored fish of the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest species richness in the Indo-Pacifi ...

es). They range in size from '' Rudarius excelsus'' (a filefish), measuring just in length, to the

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 ...

, the largest of all bony fishes at up to in length and weighing over 2 tonnes. Most members of this order – except for the family Balistidae – are ostraciiform swimmers, meaning the body is rigid and incapable of lateral flexure. Because of this, they are slow-moving and rely on their pectoral, dorsal, anal, and caudal fins for propulsion rather than body undulation. However, movement is usually quite precise; dorsal and anal fins aid in manoeuvring and stabilizing. In most species, all fins are simple, small, and rounded, except for the pelvic fins which, if present, are fused and buried. Again, in most members, the gill plates are covered over with skin, the only gill opening a small slit above the pectoral fin. The tetraodontiform strategy seems to be defense at the expense of speed, with all species fortified with scales modified into strong plates or spines – or with tough, leathery skin (the filefishes and ocean sunfish). Another striking defensive attribute found in the pufferfishes and

porcupinefish Porcupinefish are fish belonging to the family Diodontidae (order Tetraodontiformes), also commonly called blowfish and, sometimes, balloonfish and globefish. They are sometimes collectively called pufferfish, not to be confused with the morpholo ...

es is the ability to inflate their bodies to greatly increase their normal diameter; this is accomplished by sucking water into a diverticulum of the

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

. Many species of the

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

, Triodontidae, and Diodontidae are further protected from predation by

tetrodotoxin Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovere ...

, a powerful neurotoxin concentrated in the animals' internal organs. Tetraodontiforms have highly modified

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

s, with no nasal, parietal, infraorbital, or (usually) lower rib bones. The bones of the jaw are modified and fused into a sort of "

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...

"; visible sutures divide the beaks into "

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

". This is alluded to in their name, derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words ' meaning "four" and ' meaning "tooth" and the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''forma'' meaning "shape". Counting these teeth-like bones is a way of distinguishing similar families, for example, the Tetraodontidae ("four-toothed"), Triodontidae ("three-toothed"), and Diodontidae ("two-toothed"). Their jaws are aided by powerful muscles, and many species also have

pharyngeal teeth Pharyngeal teeth are teeth in the pharyngeal arch of the throat of cyprinids, suckers, and a number of other fish species otherwise lacking teeth.invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, such as

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s and

shellfish Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater envir ...

. The

Molidae The Molidae comprise the family of the molas or ocean sunfishes, unusual fish whose bodies come to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance. They are also the largest of the ray-finned bony fish, with th ...

are conspicuous even within this oddball order; they lack

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

s and spines, and are propelled by their very tall dorsal and anal fins. The caudal peduncle is absent and the caudal fin is reduced to a stiff rudder-like structure. Molids are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

rather than reef-associated and feed on soft-bodied invertebrates, especially

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

Families

This cladogram of extant Tetraodontiformes is based on Santini et al., 2013.

Fossil families

* Superfamily †Plectocretacicoidea Tyler & Sorbini, 1996 ** † Cretatriacanthidae Tyler & Sorbini, 1996 ** † Plectocretacicidae Tyler & Sorbini, 1996 ** † Protriacanthidae Tyler & Sorbini, 1996 * † Bolcabalistidae (e.g.

Eospinus ''Eospinus daniltshenkoi'' is an extinct tetraodontid bony fish from the Eocene. Its fossils are from the Danata Formation lagerstatten of Ypresian Turkmenistan. ''E. daniltshenkoi'' had four dorsal spines, three of which were on the anteri ...

) Santini & Tyler, 2003 * † Eoplectidae * † Moclaybalistidae Santini & Tyler, 2003 * †

Spinacanthidae Spinacanthidae is an extinct prehistoric family of tetraodontid bony fish that lived from the Lutetian epoch of Eocene Monte Bolca. In life, either genus would have resembled a somewhat-flattened boxfish with five massive spines along the ant ...

Timeline of genera

ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-145.5 till:15 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-145.5 ScaleMinor = unit:year increment:1 start:-145.5 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cretaceous value:rgb(0.5,0.78,0.31) id:earlycretaceous value:rgb(0.63,0.78,0.65) id:latecretaceous value:rgb(0.74,0.82,0.37) id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:NAM12 bar:NAM13 bar:NAM14 bar:NAM15 bar:NAM16 bar:NAM17 bar:NAM18 bar:NAM19 bar:NAM20 bar:NAM21 bar:NAM22 bar:NAM23 bar:NAM24 bar:NAM25 bar:NAM26 bar:NAM27 bar:NAM28 bar:NAM29 bar:NAM30 bar:NAM31 bar:NAM32 bar:NAM33 bar:NAM34 bar:NAM35 bar:NAM36 bar:NAM37 bar:NAM38 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -145.5 till: -99.6 color:earlycretaceous text: Early from: -99.6 till: -66 color:latecretaceous text:

Late Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

from: -66 till: -55.8 color:paleocene text: Paleo. from: -55.8 till: -33.9 color:eocene text: Eo. from: -33.9 till: -23.03 color:oligocene text: Oligo. from: -23.03 till: -5.332 color:miocene text: Mio. from: -5.332 till: -2.588 color:pliocene text: Pl. from: -2.588 till: -0.0117 color:pleistocene text: Pl. from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -145.5 till: -66 color:cretaceous text:

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

from: -66 till: -23.03 color:paleogene text:

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

from: -23.03 till: -2.588 color:neogene text: Neogene from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:latecretaceous bar:NAM1 from:-99.6 till:-97.6 text: Plectocretacicus color:latecretaceous bar:NAM2 from:-74.9 till:-68.9 text: Cretatriacanthus color:latecretaceous bar:NAM3 from:-70.6 till:-48.6 text: Kankatodus color:paleocene bar:NAM4 from:-66 till:-55.8 text: Indotrigonodon color:paleocene bar:NAM5 from:-66 till:-55.8 text: Pisdurodon color:paleocene bar:NAM6 from:-66 till:-33.9 text: Eotrigonodon color:eocene bar:NAM7 from:-55.8 till:-48.6 text:

color:eocene bar:NAM8 from:-55.8 till:-33.9 text: Eodiodon color:eocene bar:NAM9 from:-55.8 till:-33.9 text:

Eolactoria ''Eolactoria sorbinii'' is an extinct prehistoric boxfish that lived during the Lutetian epoch of the middle Eocene, in Monte Bolca. It had two pairs of long spines, one over each eye, and one pair beneath the anal and caudal fins, arranged ...

color:eocene bar:NAM10 from:-55.8 till:-33.9 text: Eoplectus color:eocene bar:NAM11 from:-55.8 till:-33.9 text:

Eotetraodon ''Eotetraodon'' is an extinct genus of prehistoric pufferfish that lived during the Lutetian epoch of middle Eocene. Fossil specimens are from the Monte Bolca lagerstatten (''E. pygmaeus''), and the Kuma Horizon of the Gorny Luch locality, f ...

color:eocene bar:NAM12 from:-55.8 till:-33.9 text:

Proaracana ''Proaracana dubia'' is an extinct, prehistoric aracanid boxfish that lived during the Lutetian of middle Eocene Monte Bolca. See also * ''Eolactoria'' * Prehistoric fish The evolution of fish began about 530 million years ago during th ...

color:eocene bar:NAM13 from:-55.8 till:-33.9 text: Prodiodon color:eocene bar:NAM14 from:-55.8 till:-33.9 text: Protacanthodes color:eocene bar:NAM15 from:-55.8 till:-33.9 text: Protobalistium color:eocene bar:NAM16 from:-55.8 till:-33.9 text:

Spinacanthus ''Spinacanthus cuneiformis'' is an extinct prehistoric tetraodontid bony fish that lived from the Lutetian epoch of Eocene Monte Bolca. In life, it would have resembled a somewhat-flattened boxfish with five long spines along the anterior-do ...

color:eocene bar:NAM17 from:-55.8 till:-33.9 text:

Zignoichthys ''Zignoichthys oblongus'' is an extinct prehistoric relative of the pufferfish and porcupine fish that lived during the Lutetian epoch of the Eocene. ''Z. oblongus fossils are found from the Monte Bolca lagerstätte of what is now Italy. ...

color:eocene bar:NAM18 from:-55.8 till:-33.9 text: Progymnodon color:eocene bar:NAM19 from:-55.8 till:0 text: Amanses color:eocene bar:NAM20 from:-55.8 till:0 text:

Diodon Porcupinefishes or balloonfishes, are any of the various species of the genus ''Diodon'', the type genus of Diodontidae. Distinguishing features Fish of the genus ''Diodon'' have: * two-rooted, movable spines (which are derived from modified s ...

color:eocene bar:NAM21 from:-55.8 till:0 text: Triodon color:eocene bar:NAM22 from:-55.8 till:0 text:

Ostracion ''Ostracion'' is a genus of the boxfish family Ostraciidae. Fish in the genus are known as box puffers. It was first described by Carl Linnaeus in 1758 and makes a brief appearance in Jules Verne's maritime sci-fi novel Twenty Thousand Leagues U ...

color:eocene bar:NAM23 from:-48.6 till:0 text: Triacanthus color:oligocene bar:NAM24 from:-33.9 till:-28.4 text: Acanthopleurus color:oligocene bar:NAM25 from:-33.9 till:-28.4 text: Balistomorphus color:oligocene bar:NAM26 from:-33.9 till:-28.4 text: Cryptobalistes color:oligocene bar:NAM27 from:-33.9 till:-28.4 text: Oligobalistes color:oligocene bar:NAM28 from:-33.9 till:-28.4 text:

Oligolactoria ''Oligolactoria bubiki'' is an extinct prehistoric boxfish that lived during the Rupelian epoch from the Middle Oligocene of Moravia, Czech Republic. In life, it would have strongly resembled a modern cowfish (genus ''Lactoria''). See also * ...

color:oligocene bar:NAM29 from:-33.9 till:-5.332 text: Oligodiodon color:oligocene bar:NAM30 from:-28.4 till:0 text:

Aracana ''Aracana'' is a genus of deepwater boxfishes native to the coastal waters of Australia. Species There are currently 2 recognized species in this genus:Matsuura, K. (2014): Taxonomy and systematics of tetraodontiform fishes: a review focusing ...

color:miocene bar:NAM31 from:-23.03 till:0 text: Marosichthys color:miocene bar:NAM32 from:-15.97 till:-2.588 text: Trigonodon color:miocene bar:NAM33 from:-15.97 till:0 text: Balistes color:miocene bar:NAM34 from:-15.97 till:0 text:

Tetraodon ''Tetraodon'' is a genus in the pufferfish family (Tetraodontidae) found in freshwater in Africa. It is the type genus of the family and historically included numerous other species; several Asian species were only moved to the genera ''Dichotom ...

color:miocene bar:NAM35 from:-11.608 till:0 text:

Chilomycterus ''Chilomycterus'' is a genus of diodontid tetraodontiform fishes commonly called "burrfish." Species There are currently 5 recognized species in this genus:Matsuura, K. (2014): Taxonomy and systematics of tetraodontiform fishes: a review focusi ...

color:miocene bar:NAM36 from:-11.608 till:0 text: Mola color:pliocene bar:NAM37 from:-5.332 till:-2.588 text: Kyrtogymnodon color:pliocene bar:NAM38 from:-5.332 till:0 text: Alutera PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -145.5 till: -99.6 color:earlycretaceous text: Early from: -99.6 till: -66 color:latecretaceous text:

from: -66 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text: Neogene from: -2.588 till: 0 color:quaternary text: Q.

References

*
Tree of Life: Tetraodontiformes
* {{Taxonbar, from=Q211837 Extant Cenomanian first appearances