83-411: See text 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 , blowers , blowies , bubblefish , globefish , swellfish , toadfish , toadies , toadle , honey toads , sugar toads , and sea squab . They are morphologically similar to
166-404: A comparatively easy predation target. Its tail fin is mainly used as a rudder, but it can be used for a sudden evasive burst of speed that shows none of the care and precision of its usual movements. The puffer's excellent eyesight, combined with this speed burst, is the first and most important defense against predators. The pufferfish's secondary defense mechanism, used if successfully pursued,
249-514: A completely vegetarian diet if their environment is lacking resources, but prefer an omnivorous food selection. Larger species of pufferfish are able to use their beak-like front teeth to break open clams, mussels, and other shellfish. Some species of pufferfish have also been known to enact various hunting techniques ranging from ambush to open-water hunting. The tetraodontids have been estimated to have diverged from diodontids between 89 and 138 million years ago. The four major clades diverged during
332-457: A consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time
415-430: A different reason. Unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a vapor film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage. Scombrid fishes (tuna, mackerel and bonito) are particularly high-performance swimmers. Along
498-446: A family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching
581-557: A few species such as the Mbu pufferfish can reach lengths greater than 50 cm (20 in). Tetraodontiformes , or pufferfish, are most significantly characterized by the beak-like four teeth – hence the name combining the Greek terms "tetra" for four and "odous" for tooth. Each of the top and bottom arches is fused together with a visible midsagittal demarcation, which are used to break apart and consume small crustaceans . The lack of ribs,
664-442: A homocercal tail. These come in a variety of shapes, and can appear: (D) - Diphycercal means the vertebrae extend to the tip of the tail and the tail is symmetrical and expanded (as in the bichir , lungfish , lamprey , coelacanths and † Tarrasiiformes ). Most Palaeozoic fishes had a diphycercal heterocercal tail. Finlets are small fins, generally behind the dorsal and anal fins (in bichirs , there are only finlets on
747-546: A lethal effect on large predators, such as sharks, but it can kill humans. Larval pufferfish are chemically defended by the presence of TTX on the surface of skin, which causes predators to spit them out. Not all puffers are necessarily poisonous; the flesh of the northern puffer is not toxic (a level of poison can be found in its viscera ) and it is considered a delicacy in North America. Toxin level varies widely even in fish that are poisonous. A puffer's neurotoxin
830-515: A liquid, which then promptly and violently collapse. It can cause significant damage and wear. Cavitation damage can occur to the tail fins of powerful swimming marine animals, such as dolphins and tuna. Cavitation is more likely to occur near the surface of the ocean, where the ambient water pressure is relatively low. Even if they have the power to swim faster, dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for
913-579: A matter of debate, but it is increasingly accepted that bacteria in the fish's intestinal tract are the source. Saxitoxin , the cause of paralytic shellfish poisoning and red tide , can also be found in certain puffers. In September 2012, the Bureau of Fisheries and Aquatic Resources in the Philippines issued a warning not to eat puffer fish, after local fishermen died upon consuming puffer fish for dinner. The warning indicated that puffer fish toxin
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#1732794622710996-508: A modified fin to deliver sperm; thresher sharks use their caudal fin to whip and stun prey; reef stonefish have spines in their dorsal fins that inject venom as an anti-predator defense ; anglerfish use the first spine of their dorsal fin like a fishing rod to lure prey; and triggerfish avoid predators by squeezing into coral crevices and using spines in their fins to anchor themselves in place. Fins can either be paired or unpaired . The pectoral and pelvic fins are paired, whereas
1079-439: A more disproportionate way than other fins on female fish." There are two prevailing hypotheses that have been historically debated as models for the evolution of paired fins in fish: the gill arch theory and the lateral fin-fold theory. The former, commonly referred to as the " Gegenbaur hypothesis ," was posited in 1870 and proposes that the "paired fins are derived from gill structures". This fell out of popularity in favor of
1162-416: A neural network in the fin, indicating that it likely has a sensory function, but are still not sure exactly what the consequences of removing it are. A comparative study in 2013 indicates the adipose fin can develop in two different ways. One is the salmoniform-type way, where the adipose fin develops from the larval-fin fold at the same time and in the same direct manner as the other median fins. The other
1245-705: A pancake, and will fit into fissures in rocks. Their pelvic and pectoral fins have evolved differently, so they act together with the flattened body to optimise manoeuvrability. Some fishes, such as puffer fish , filefish and trunkfish , rely on pectoral fins for swimming and hardly use tail fins at all. Male cartilaginous fishes (sharks and rays), as well as the males of some live-bearing ray finned fishes , have fins that have been modified to function as intromittent organs , reproductive appendages which allow internal fertilization . In ray finned fish, they are called gonopodia or andropodia , and in cartilaginous fish, they are called claspers . Gonopodia are found on
1328-417: A pelvis, and pelvic fins are also unique to pufferfish. The notably missing bone and fin features are due to the pufferfish' specialized defense mechanism, expanding by sucking in water through an oral cavity. Pufferfish can also have many varied structures of caltrop -like dermal spines, which account for the replacement of typical fish scales, and can range in coverage extent from the entire body, to leaving
1411-549: A prominent dorsal fin. Like scombroids and other billfish , they streamline themselves by retracting their dorsal fins into a groove in their body when they swim. The huge dorsal fin, or sail, of the sailfish is kept retracted most of the time. Sailfish raise them if they want to herd a school of small fish, and also after periods of high activity, presumably to cool down. The oriental flying gurnard has large pectoral fins which it normally holds against its body, and expands when threatened to scare predators. Despite its name, it
1494-436: A shape usually reminiscent of a pufferfish. They have a functional mouth and eyes, and must eat within a few days. Brackish-water puffers may breed in bays in a manner similar to marine species, or may breed more similarly to the freshwater species, in cases where they have moved far enough upriver. Reproduction in freshwater species varies quite a bit. The dwarf puffers court with males following females, possibly displaying
1577-494: A similar courting behavior, minus the crest/keel display. Eggs are laid, though, on a flat piece of slate or other smooth, hard material, to which they adhere. The male will guard them until they hatch, carefully blowing water over them regularly to keep the eggs healthy. His parenting is finished when the young hatch and the fry are on their own. In 2012, males of the species Torquigener albomaculosus were documented while carving large and complex geometric, circular structures in
1660-454: A thin stretch of scaleless skin ; in lobe-finned fish ( Sarcopterygii ) such as coelacanths and lungfish , fins are short rays based around a muscular central bud supported by jointed bones ; in cartilaginous fish ( Chondrichthyes ) and jawless fish ( Agnatha ), fins are fleshy " flippers " supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups:
1743-494: Is 100 times more potent than cyanide . Pufferfish, called pakapao in Thailand , are usually consumed by mistake. They are often cheaper than other fish, and because they contain inconsistent levels of toxins between fish and season, there is little awareness or monitoring of the danger. Consumers are regularly hospitalized and some even die from the poisoning. Cases of neurological symptoms, including numbness and tingling of
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#17327946227101826-413: Is a demersal fish , not a flying fish, and uses its pelvic fins to walk along the bottom of the ocean. Fins can have an adaptive significance as sexual ornaments. During courtship, the female cichlid , Pelvicachromis taeniatus , displays a large and visually arresting purple pelvic fin . "The researchers found that males clearly preferred females with a larger pelvic fin and that pelvic fins grew in
1909-501: Is likely an example of honestly signaled aposematism . Dolphins have been filmed expertly handling pufferfish amongst themselves in an apparent attempt to get intoxicated or enter a trance-like state. Many marine puffers have a pelagic , or open-ocean, life stage. Spawning occurs after males slowly push females to the water surface or join females already present. The eggs are spherical and buoyant. Hatching occurs after roughly four days. The fry are tiny, but under magnification have
1992-524: Is not necessarily as toxic to other animals as it is to humans, and puffers are eaten routinely by some species of fish, such as lizardfish and sharks . Puffers are able to move their eyes independently, and many species can change the color or intensity of their patterns in response to environmental changes. In these respects, they are somewhat similar to the terrestrial chameleon . Although most puffers are drab, many have bright colors and distinctive markings, and make no attempt to hide from predators. This
2075-628: Is one type of living lobe-finned fish. Both extant members of this group, the West Indian Ocean coelacanth ( Latimeria chalumnae ) and the Indonesian coelacanth ( Latimeria menadoensis ), are found in the genus Latimeria . Coelacanths are thought to have evolved roughly into their current form about 408 million years ago, during the early Devonian. Locomotion of the coelacanths is unique to their kind. To move around, coelacanths most commonly take advantage of up or downwellings of
2158-436: Is prohibited in many countries. Foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic animals get significant thrust by moving fins back and forth in water. Often the tail fin is used, but some aquatic animals generate thrust from pectoral fins . Cavitation occurs when negative pressure causes bubbles (cavities) to form in
2241-432: Is relatively conservative in lobe-finned fishes. However, there are a few examples from the fossil record that show aberrant morphologies , such as Allenypterus , Rebellatrix , Foreyia or the tetrapodomorphs . Ray-finned fishes form a class of bony fishes called Actinopterygii. Their fins contain spines or rays. A fin may contain only spiny rays, only soft rays, or a combination of both. If both are present,
2324-402: Is something of a mystery. It is frequently clipped off to mark hatchery-raised fish, though data from 2005 showed that trout with their adipose fin removed have an 8% higher tailbeat frequency. Additional information released in 2011 has suggested that the fin may be vital for the detection of, and response to, stimuli such as touch, sound and changes in pressure. Canadian researchers identified
2407-487: Is the characiform-type way, where the adipose fin develops late after the larval-fin fold has diminished and the other median fins have developed. They claim the existence of the characiform-type of development suggests the adipose fin is not "just a larval fin fold remainder" and is inconsistent with the view that the adipose fin lacks function. Research published in 2014 indicates that the adipose fin has evolved repeatedly in separate lineages . (A) - Heterocercal means
2490-433: Is the heterocercal tail, which aids in locomotion. Most sharks have eight fins. Sharks can only drift away from objects directly in front of them because their fins do not allow them to move in the tail-first direction. Unlike modern cartilaginous fish, members of stem chondrichthyan lineages (e.g. the † climatiids and the † diplacanthids ) possessed pectoral dermal plates as well as dermal spines associated with
2573-400: Is the largest class of vertebrates in existence today, making up more than 50% of species. In the distant past, lobe-finned fish were abundant; however, there are currently only 8 species. Bony fish have fin spines called lepidotrichia or "rays" (due to how the spines spread open). They typically have swim bladders , which allow the fish to alter the relative density of its body and thus
Tetraodontidae - Misplaced Pages Continue
2656-598: Is thought that their rostral organ helps give the coelacanth electroperception, which aids in their movement around obstacles. Lungfish are also living lobe-finned fish. They occur in Africa ( Protopterus ), Australia ( Neoceratodus ), and South America ( Lepidosiren ). Lungfish evolved during the Devonian Period. Genetic studies and paleontological data confirm that lungfish are the closest living relatives of land vertebrates . Fin arrangement and body shape
2739-423: Is to fill its extremely elastic stomach with water (or air when outside the water) until it is much larger and almost spherical in shape. Even if they are not visible when the puffer is not inflated, all puffers have pointed spines, so a hungry predator may suddenly find itself facing an unpalatable, pointy ball rather than a slow, easy meal. Predators that do not heed this warning (or are "lucky" enough to catch
2822-524: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Pectoral fin Fins are moving appendages protruding from
2905-719: The Cretaceous between 80 and 101 million years ago. The oldest known pufferfish genus is Eotetraodon , from the Lutetian epoch of Middle Eocene Europe, with fossils found in Monte Bolca and the Caucasus Mountains . The Monte Bolca species, E. pygmaeus , coexisted with several other tetraodontiforms, including an extinct species of diodontid, primitive boxfish ( Proaracana and Eolactoria ), and other, totally extinct forms, such as Zignoichthys and
2988-584: The Humane Society International , approximately 100 million sharks are killed each year for their fins, in an act known as shark finning . After the fins are cut off, the mutilated sharks are thrown back in the water and left to die. In some countries of Asia , shark fins are a culinary delicacy, such as shark fin soup . Currently, international concerns over the sustainability and welfare of sharks have impacted consumption and availability of shark fin soup worldwide. Shark finning
3071-484: The Middle Triassic † Saurichthys , the oldest known example of viviparity in a ray-finned fish. Claspers are found on the males of cartilaginous fishes . They are the posterior part of the pelvic fins that have also been modified to function as intromittent organs, and are used to channel semen into the female's cloaca during copulation. The act of mating in sharks usually includes raising one of
3154-417: The buoyancy , so it can sink or float without having to use the fins to swim up and down. However, swim bladders are absent in many fish, most notably in lungfishes , who have evolved their swim bladders into primitive lungs , which may have a shared evolutionary origin with those of their terrestrial relatives, the tetrapods . Bony fishes also have a pair of opercula that function to draw water across
3237-409: The extinct † Petalodontiformes (e.g. † Belantsea , † Janassa , † Menaspis ), which belong to Holocephali (ratfish and their fossil relatives), or in † Aquilolamna ( Selachimorpha ) and † Squatinactis (Squatinactiformes). Some cartilaginous fishes have an eel-like locomotion (e.g. Chlamydoselachus , † Thrinacoselache , † Phoebodus ) According to
3320-426: The gills , which help them breathe without needing to swim forward to force the water into the mouth across the gills. Lobe-finned fishes form a class of bony fishes called Sarcopterygii. They have fleshy, lobed , paired fins, which are joined to the body by a series of bones. The fins of lobe-finned fish differ from those of all other fish in that each is borne on a fleshy, lobe-like, scaly stalk extending from
3403-831: The midsagittal unpaired fins and the more laterally located paired fins . Unpaired fins are predominantly associated with generating linear acceleration via oscillating propulsion , as well as providing directional stability ; while paired fins are used for generating paddling acceleration , deceleration, and differential thrust or lift for turning , surfacing or diving and rolling . Fins can also be used for other locomotions other than swimming, for example, flying fish use pectoral fins for gliding flight above water surface, and frogfish and many amphibious fishes use pectoral and/or pelvic fins for crawling . Fins can also be used for other purposes: remoras and gobies have evolved sucker -like dorsal fins for attaching to surfaces and "hitchhiking"; male sharks and mosquitofish use
Tetraodontidae - Misplaced Pages Continue
3486-447: The spinacanthids . The extinct genus, Archaeotetraodon is known from Miocene -aged fossils from Europe. Pufferfish can be lethal if not served properly. Puffer poisoning usually results from consumption of incorrectly prepared puffer soup, fugu chiri , or occasionally from raw puffer meat, sashimi fugu . While chiri is much more likely to cause death, sashimi fugu often causes intoxication, light-headedness, and numbness of
3569-471: The ventral portion. This is because the shark's vertebral column extends into that dorsal portion, providing a greater surface area for muscle attachment. This allows more efficient locomotion among these negatively buoyant cartilaginous fish. By contrast, most bony fish possess a homocercal caudal fin. Tiger sharks have a large upper lobe , which allows for slow cruising and sudden bursts of speed. The tiger shark must be able to twist and turn in
3652-434: The ability to lock their spines outwards. Triggerfish also use spines to lock themselves in crevices to prevent them being pulled out. Lepidotrichia are usually composed of bone , but those of early osteichthyans - such as Cheirolepis - also had dentine and enamel . They are segmented and appear as a series of disks stacked one on top of another. They may have been derived from dermal scales. The genetic basis for
3735-427: The body of fish that interact with water to generate thrust and help the fish swim . Apart from the tail or caudal fin , fish fins have no direct connection with the back bone and are supported only by muscles . Fish fins are distinctive anatomical features with varying structures among different clades : in ray-finned fish ( Actinopterygii ), fins are mainly composed of bony spines or rays covered by
3818-521: The body. Pectoral and pelvic fins have articulations resembling those of tetrapod limbs. These fins evolved into legs of the first tetrapod land vertebrates ( amphibians ) in the Devonian Period . Sarcopterygians also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of most ray-finned fish (except some teleosts ). The caudal fin is either heterocercal (only fossil taxa ) or diphycercal. The coelacanth
3901-514: The book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
3984-548: The claspers to allow water into a siphon through a specific orifice . The clasper is then inserted into the cloaca, where it opens like an umbrella to anchor its position. The siphon then begins to contract expelling water and sperm. Other uses of fins include walking and perching on the sea floor, gliding over water, cooling of body temperature, stunning of prey, display (scaring of predators, courtship), defence (venomous fin spines, locking between corals), luring of prey, and attachment structures. The Indo-Pacific sailfish has
4067-529: The closely related porcupinefish , which have large external spines (unlike the thinner, hidden spines of the Tetraodontidae, which are only visible when the fish have puffed up). The majority of pufferfish species are toxic , with some among the most poisonous vertebrates in the world. In certain species, the internal organs, such as the liver, and sometimes the skin, contain tetrodotoxin , and are highly toxic to most animals when eaten; nevertheless,
4150-424: The crests and keels unique to this subgroup of species. After the female accepts his advances, she will lead the male into plants or another form of cover, where she can release eggs for fertilization. The male may help her by rubbing against her side. This has been observed in captivity, and they are the only commonly captive-spawned puffer species. Target-group puffers have also been spawned in aquaria, and follow
4233-465: The current and drift. They use their paired fins to stabilize their movement through the water. While on the ocean floor their paired fins are not used for any kind of movement. Coelacanths can create thrust for quick starts by using their caudal fins. Due to the high number of fins they possess, coelacanths have high maneuverability and can orient their bodies in almost any direction in the water. They have been seen doing headstands and swimming belly up. It
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#17327946227104316-738: The dorsal surface and no dorsal fin). In some fish such as tuna or sauries , they are rayless, non-retractable, and found between the last dorsal and/or anal fin and the caudal fin. Bony fishes ( Actinopterygii and Sarcopterygii ) form a taxonomic group called Osteichthyes (or Euteleostomi , which includes also land vertebrates ); they have skeletons made of bone mostly, and can be contrasted with cartilaginous fishes (see below), which have skeletons made mainly of cartilage (except for their teeth , fin spines , and denticles ). Bony fishes are divided into ray-finned and lobe-finned fish . Most living fish are ray-finned, an extremely diverse and abundant group consisting of over 30,000 species . It
4399-525: The dorsal, anal and caudal fins are unpaired and situated along the midline of the body. For every type of fin, there are a number of fish species in which this particular fin has been lost during evolution (e.g. pelvic fins in † Bobasatrania , caudal fin in ocean sunfish ). In some clades , additional unpaired fins were acquired during evolution (e.g. additional dorsal fins, adipose fin). In some † Acanthodii ("spiny sharks"), one or more pairs of "intermediate" or "prepelvic" spines are present between
4482-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
4565-442: The female. The male shortly inserts the organ into the sex opening of the female, with hook-like adaptations that allow the fish to grip onto the female to ensure impregnation. If a female remains stationary and her partner contacts her vent with his gonopodium, she is fertilized. The sperm is preserved in the female's oviduct. This allows females to fertilize themselves at any time without further assistance from males. In some species,
4648-400: The first dorsal fin spine was modified, forming a spine-brush complex. As with most fish, the tails of sharks provide thrust, making speed and acceleration dependent on tail shape. Caudal fin shapes vary considerably between shark species, due to their evolution in separate environments. Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than
4731-501: The formation of a linked chain of vortex rings" and that "the dorsal and anal fin wakes are rapidly entrained by the caudal fin wake, approximately within the timeframe of a subsequent tail beat". Once motion has been established, the motion itself can be controlled with the use of other fins. The bodies of reef fishes are often shaped differently from open water fishes . Open water fishes are usually built for speed, streamlined like torpedoes to minimise friction as they move through
4814-553: The formation of the fin rays is thought to be genes coded for the production of certain proteins. It has been suggested that the evolution of the tetrapod limb from lobe-finned fishes is related to the loss of these proteins. Cartilaginous fishes form a class of fishes called Chondrichthyes. They have skeletons made of cartilage rather than bone . The class includes sharks , rays and chimaeras . Shark fin skeletons are elongated and supported with soft and unsegmented rays named ceratotrichia, filaments of elastic protein resembling
4897-953: The frontal surface empty. Tetraodontidae typically have smaller spines than the sister family Diodontidae , with some spines not being visible until inflation. They are most diverse in the tropics , relatively uncommon in the temperate zone , and completely absent from cold waters . Most pufferfish species live in marine or brackish waters, but some can enter fresh water. About 35 species spend their entire lifecycles in fresh water. These freshwater species are found in disjunct tropical regions of South America ( Colomesus asellus and Colomesus tocantinensis ), Africa (six Tetraodon species), and Southeast Asia ( Auriglobus , Carinotetraodon , Dichotomyctere , Leiodon and Pao ). The puffer's unique and distinctive natural defenses help compensate for its slow locomotion. It moves by combining pectoral , dorsal , anal , and caudal fin motions. This makes it highly maneuverable, but very slow, so
4980-522: The gonopodium may be half the total body length. Occasionally the fin is too long to be used, as in the "lyretail" breeds of Xiphophorus helleri . Hormone treated females may develop gonopodia. These are useless for breeding. Similar organs with similar characteristics are found in other fishes, for example the andropodium in the Hemirhamphodon or in the Goodeidae or the gonopodium in
5063-410: The horny keratin in hair and feathers. Originally the pectoral and pelvic girdles, which do not contain any dermal elements, did not connect. In later forms, each pair of fins became ventrally connected in the middle when scapulocoracoid and puboischiadic bars evolved. In rays , the pectoral fins have connected to the head and are very flexible. One of the primary characteristics present in most sharks
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#17327946227105146-443: The lateral fin-fold theory, first suggested in 1877, which proposes that paired fins budded from longitudinal, lateral folds along the epidermis just behind the gills. There is weak support for both hypotheses in the fossil record and in embryology. However, recent insights from developmental patterning have prompted reconsideration of both theories in order to better elucidate the origins of paired fins. Carl Gegenbaur 's concept of
5229-482: The lips and mouth, have been reported to rise after the consumption of puffers caught in the area of Titusville, Florida , US. The symptoms generally resolve within hours to days, although one affected individual required intubation for 72 hours. As a result, Florida banned the harvesting of puffers from certain bodies of water. Treatment is mainly supportive and consists of intestinal decontamination with gastric lavage and activated charcoal , and life-support until
5312-478: The lips. Pufferfish tetrodotoxin deadens the tongue and lips, and induces dizziness and vomiting, followed by numbness and prickling over the body, rapid heart rate, decreased blood pressure , and muscle paralysis . The toxin paralyzes the diaphragm muscle and stops the person who has ingested it from breathing. People who live longer than 24 hours typically survive, although possibly after a coma lasting several days. The source of tetrodotoxin in puffers has been
5395-499: The males of some species in the Anablepidae and Poeciliidae families. They are anal fins that have been modified to function as movable intromittent organs and are used to impregnate females with milt during mating. The third, fourth and fifth rays of the male's anal fin are formed into a tube-like structure in which the sperm of the fish is ejected. When ready for mating, the gonopodium becomes erect and points forward towards
5478-458: The margin at the rear of their bodies is a line of small rayless, non-retractable fins, known as finlets . There has been much speculation about the function of these finlets. Research done in 2000 and 2001 by Nauen and Lauder indicated that "the finlets have a hydrodynamic effect on local flow during steady swimming" and that "the most posterior finlet is oriented to redirect flow into the developing tail vortex, which may increase thrust produced by
5561-509: The meat of some species is considered a delicacy in Japan (as 河豚, pronounced fugu ), Korea (as 복, bok , or 복어, bogeo ), and China (as 河豚, hétún ) when prepared by specially trained chefs who know which part is safe to eat and in what quantity. Other pufferfish species with nontoxic flesh, such as the northern puffer , Sphoeroides maculatus , of Chesapeake Bay , are considered a delicacy elsewhere. The species Torquigener albomaculosus
5644-696: The paired fins. The oldest species demonstrating these features is the † acanthodian † Fanjingshania renovata from the lower Silurian ( Aeronian ) of China. Fanjingshania possess compound pectoral plates composed of dermal scales fused to a bony plate and fin spines formed entirely of bone. Fin spines associated with the dorsal fins are rare among extant cartilaginous fishes, but are present, for instance, in Heterodontus or Squalus . Dorsal fin spines are typically developed in many fossil groups, such as in † Hybodontiformes , † Ctenacanthiformes or † Xenacanthida . In † Stethacanthus ,
5727-403: The pectoral and pelvic fins, but these are not associated with fins. The pelvic fin assists the fish in going up or down through the water, turning sharply, and stopping quickly. The dorsal fins are located on the back. A fish can have up to three dorsal fins. The dorsal fins serve to protect the fish against rolling, and assist it in sudden turns and stops. The function of the adipose fin
5810-429: The puffer suddenly, before or during inflation) may die from choking, and predators that do manage to swallow the puffer may find their stomachs full of tetrodotoxin (TTX), making puffers an unpleasant, possibly lethal, choice of prey. This neurotoxin is found primarily in the ovaries and liver , although smaller amounts exist in the intestines and skin , as well as trace amounts in muscle. It does not always have
5893-491: The ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging
5976-452: The seabed sand in Amami Ōshima , Japan. The structures serve to attract females and to provide a safe place for them to lay their eggs. Information on breeding of specific species is very limited. T. nigroviridis , the green-spotted puffer, has recently been spawned artificially under captive conditions. It is believed to spawn in bays in a similar manner to saltwater species, as their sperm
6059-402: The spiny rays are always anterior . Spines are generally stiff and sharp. Rays are generally soft, flexible, segmented, and may be branched. This segmentation of rays is the main difference that separates them from spines; spines may be flexible in certain species, but they will never be segmented. Spines have a variety of uses. In catfish , they are used as a form of defense; many catfish have
6142-552: The tail of swimming mackerel". Fish use multiple fins, so it is possible that a given fin can have a hydrodynamic interaction with another fin. In particular, the fins immediately upstream of the caudal (tail) fin may be proximate fins that can directly affect the flow dynamics at the caudal fin. In 2011, researchers using volumetric imaging techniques were able to generate "the first instantaneous three-dimensional views of wake structures as they are produced by freely swimming fishes". They found that "continuous tail beats resulted in
6225-450: The tip of the tail and the tail is symmetrical but not expanded (as in the first fishes and the cyclostomes , and a more primitive precursor in lancelets ) (C) - Homocercal where the fin usually appears superficially symmetric but in fact the vertebrae extend for a very short distance into the upper lobe of the fin. Homocercal caudal fins can, however, also appear asymmetric (e.g. blue flying fish ). Most modern fishes ( teleosts ) have
6308-461: The toxin is metabolized. Case reports suggest anticholinesterases such as edrophonium may be effective. Family (biology) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between
6391-419: The vertebrae extend into the upper lobe of the tail, often making it longer than the lower lobe (as in sharks , † Placodermi , most stem Actinopterygii , and sturgeons and paddlefish ). However, the external shape of heterocercal tail fins can also appear symmetric (e.g. † Birgeria , † Bobasatrania ). Heterocercal is the opposite of hypocercal (B) - Protocercal means the vertebrae extend to
6474-511: The water easily when hunting to support its varied diet, whereas the porbeagle shark , which hunts schooling fish such as mackerel and herring , has a large lower lobe to help it keep pace with its fast-swimming prey. Other tail adaptations help sharks catch prey more directly, such as the thresher shark 's usage of its powerful, elongated upper lobe to stun fish and squid. On the other hand, rays rely on their enlarged pectoral fins for propulsion. Similarly enlarged pectoral fins can be found in
6557-697: The water. Reef fish operate in the relatively confined spaces and complex underwater landscapes of coral reefs . For this manoeuvrability is more important than straight line speed, so coral reef fish have developed bodies which optimize their ability to dart and change direction. They outwit predators by dodging into fissures in the reef or playing hide and seek around coral heads. The pectoral and pelvic fins of many reef fish, such as butterflyfish , damselfish and angelfish , have evolved so they can act as brakes and allow complex manoeuvres. Many reef fish, such as butterflyfish , damselfish and angelfish , have evolved bodies which are deep and laterally compressed like
6640-529: The “Archipterygium” was introduced in 1876. It was described as a gill ray, or "joined cartilaginous stem," that extended from the gill arch. Additional rays arose from along the arch and from the central gill ray. Gegenbaur suggested a model of transformative homology – that all vertebrate paired fins and limbs were transformations of the Archipterygium. Based on this theory, paired appendages such as pectoral and pelvic fins would have differentiated from
6723-516: Was described by David Attenborough as "the greatest artist of the animal kingdom" due to the males' unique habit of wooing females by creating nests in sand composed of complex geometric designs. The family name comes from the name of its type genus Tetraodon ; it is traced from the Greek words τετρα tetra meaning "four" and ὀδούς odoús meaning "teeth". The Tetraodontidae contains 193 to 206 species of puffers in 27 or 28 genera: Pufferfish are typically small to medium in size, although
6806-553: Was found to be motile only at full marine salinities, but wild breeding has never been observed. Xenopterus naritus has been reported to be the first bred artificially in Sarawak, Northwestern Borneo, in June 2016, and the main purpose was for development of aquaculture of the species. Pufferfish diets can vary depending on their environment. Traditionally, their diet consists mostly of algae and small invertebrates. They can survive on
6889-488: Was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted the use of this term solely within
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