A FISH is any member of a group of animals that consist of all gill -bearing aquatic craniate animals that lack limbs with digits . They form a sister group to the tunicates , together forming the olfactores . Included in this definition are the living hagfish , lampreys , and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes , so cladistically they are fish as well. However, traditionally fish are rendered obsolete or paraphyletic by excluding the tetrapods (i.e., the amphibians , reptiles , birds and mammals which all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology . The traditional term PISCES (also ICHTHYES) is considered a typological, but not a phylogenetic classification.
The earliest organisms that can be classified as fish were
soft-bodied chordates that first appeared during the
Most fish are ectothermic ("cold-blooded"), allowing their body
temperatures to vary as ambient temperatures change, though some of
the large active swimmers like white shark and tuna can hold a higher
core temperature .
* 1 Evolution
* 1.1 Taxonomy
* 2 Diversity
* 3 Anatomy and physiology
* 3.1 Respiration
* 3.1.1 Gills * 3.1.2 Air breathing
* 3.2 Circulation * 3.3 Digestion * 3.4 Excretion * 3.5 Scales
* 3.6 Sensory and nervous system
* 3.6.1 Central nervous system
* 3.6.2 Sense organs
* 188.8.131.52 Vision * 184.108.40.206 Hearing
* 3.6.3 Capacity for pain
* 3.7 Muscular system * 3.8 Homeothermy * 3.9 Reproductive system
* 4 Diseases
* 4.1 Immune system
* 5 Conservation
* 5.1 Overfishing * 5.2 Habitat destruction * 5.3 Exotic species
* 6 Importance to humans
* 6.1 Economic importance * 6.2 Recreation * 6.3 Culture
* 7 Terminology
* 8 See also * 9 Notes * 10 References * 11 Further reading * 12 External links
Early fish from the fossil record are represented by a group of small, jawless, armored fish known as ostracoderms . Jawless fish lineages are mostly extinct. An extant clade, the lampreys may approximate ancient pre-jawed fish. The first jaws are found in Placodermi fossils. The diversity of jawed vertebrates may indicate the evolutionary advantage of a jawed mouth . It is unclear if the advantage of a hinged jaw is greater biting force, improved respiration, or a combination of factors.
Traditional classification divide fish into three extant classes , and with extinct forms sometimes classified within the tree, sometimes as their own classes:
* Class Agnatha (jawless fish)
* Class Chondrichthyes (cartilaginous fish)
Leedsichthys (left), of the subclass Actinopterygii, is the largest known fish, with estimates in 2005 putting its maximum size at 16 metres (52 ft)
* Class Osteichthyes (bony fish)
The above scheme is the one most commonly encountered in non-specialist and general works. Many of the above groups are paraphyletic, in that they have given rise to successive groups: Agnathans are ancestral to Chondrichthyes, who again have given rise to Acanthodiians, the ancestors of Osteichthyes. With the arrival of phylogenetic nomenclature , the fishes has been split up into a more detailed scheme, with the following major groups:
* Class Petromyzontida or
* Petromyzontidae (lampreys )
* Class Conodonta (conodonts) †
* Infraphylum Gnathostomata (jawed vertebrates)
* Superclass Osteichthyes (bony fish)
* Class Actinopterygii (ray-finned fish)
* Subclass Chondrostei
* Subclass Neopterygii
* Class Sarcopterygii (lobe-finned fish)
* Subclass Actinistia (coelacanths ) * Subclass Dipnoi (lungfish )
† – indicates extinct taxon Some palaeontologists contend that because Conodonta are chordates , they are primitive fish. For a fuller treatment of this taxonomy, see the vertebrate article.
The position of hagfish in the phylum
The various fish groups account for more than half of vertebrate
species. There are almost 28,000 known extant species, of which almost
27,000 are bony fish, with 970 sharks, rays, and chimeras and about
108 hagfish and lampreys. A third of these species fall within the
nine largest families; from largest to smallest, these families are
Main article: Diversity of fish
Agnatha ( Pacific hagfish ) *
Chondrichthyes ( Horn shark ) *
The term "fish" most precisely describes any non-tetrapod craniate (i.e. an animal with a skull and in most cases a backbone) that has gills throughout life and whose limbs, if any, are in the shape of fins. Unlike groupings such as birds or mammals , fish are not a single clade but a paraphyletic collection of taxa , including hagfishes , lampreys , sharks and rays , ray-finned fish , coelacanths , and lungfish . Indeed, lungfish and coelacanths are closer relatives of tetrapods (such as mammals , birds, amphibians , etc.) than of other fish such as ray-finned fish or sharks, so the last common ancestor of all fish is also an ancestor to tetrapods. As paraphyletic groups are no longer recognised in modern systematic biology , the use of the term "fish" as a biological group must be avoided.
Many types of aquatic animals commonly referred to as "fish" are not fish in the sense given above; examples include shellfish , cuttlefish , starfish , crayfish and jellyfish . In earlier times, even biologists did not make a distinction – sixteenth century natural historians classified also seals , whales, amphibians , crocodiles , even hippopotamuses , as well as a host of aquatic invertebrates, as fish. However, according to the definition above, all mammals, including cetaceans like whales and dolphins, are not fish. In some contexts, especially in aquaculture , the true fish are referred to as FINFISH (or FIN FISH) to distinguish them from these other animals. sea dragon , a close relative of the seahorse . Their leaf-like appendages camouflage them amongst floating seaweed .
A typical fish is ectothermic , has a streamlined body for rapid swimming, extracts oxygen from water using gills or uses an accessory breathing organ to breathe atmospheric oxygen, has two sets of paired fins, usually one or two (rarely three) dorsal fins, an anal fin, and a tail fin, has jaws, has skin that is usually covered with scales , and lays eggs.
Each criterion has exceptions. Tuna , swordfish , and some species of sharks show some warm-blooded adaptations —they can heat their bodies significantly above ambient water temperature. Streamlining and swimming performance varies from fish such as tuna , salmon , and jacks that can cover 10–20 body-lengths per second to species such as eels and rays that swim no more than 0.5 body-lengths per second. Many groups of freshwater fish extract oxygen from the air as well as from the water using a variety of different structures. Lungfish have paired lungs similar to those of tetrapods, gouramis have a structure called the labyrinth organ that performs a similar function, while many catfish, such as Corydoras extract oxygen via the intestine or stomach. Body shape and the arrangement of the fins is highly variable, covering such seemingly un-fishlike forms as seahorses , pufferfish , anglerfish , and gulpers . Similarly, the surface of the skin may be naked (as in moray eels ), or covered with scales of a variety of different types usually defined as placoid (typical of sharks and rays), cosmoid (fossil lungfish and coelacanths), ganoid (various fossil fish but also living gars and bichirs ), cycloid , and ctenoid (these last two are found on most bony fish ). There are even fish that live mostly on land or lay their eggs on land near water. Mudskippers feed and interact with one another on mudflats and go underwater to hide in their burrows. A single, an undescribed species of Phreatobius , has been called a true "land fish" as this worm-like catfish strictly lives among waterlogged leaf litter . Many species live in underground lakes , underground rivers or aquifers and are popularly known as cavefish .
ANATOMY AND PHYSIOLOGY
Further information: Fish anatomy and Fish physiology The anatomy of Lampanyctodes hectoris (1) – operculum (gill cover), (2) – lateral line, (3) – dorsal fin, (4) – fat fin, (5) – caudal peduncle, (6) – caudal fin, (7) – anal fin, (8) – photophores, (9) – pelvic fins (paired), (10) – pectoral fins (paired)
See also: Aquatic respiration
Most fish exchange gases using gills on either side of the pharynx .
Gills consist of threadlike structures called filaments . Each
filament contains a capillary network that provides a large surface
area for exchanging oxygen and carbon dioxide .
Juvenile bichirs have external gills, a very primitive feature that they share with larval amphibians .
Tuna gills inside the head. The fish head is oriented snout-downwards, with the view looking towards the mouth.
Breathing air is primarily of use to fish that inhabit shallow,
seasonally variable waters where the water's oxygen concentration may
Air breathing fish can be divided into OBLIGATE AIR BREATHERS and FACULTATIVE AIR BREATHERS. Obligate air breathers, such as the African lungfish , must breathe air periodically or they suffocate. Facultative air breathers, such as the catfish Hypostomus plecostomus , only breathe air if they need to and will otherwise rely on their gills for oxygen. Most air breathing fish are facultative air breathers that avoid the energetic cost of rising to the surface and the fitness cost of exposure to surface predators.
Didactic model of a fish heart.
Jaws allow fish to eat a wide variety of food, including plants and
As with many aquatic animals, most fish release their nitrogenous wastes as ammonia . Some of the wastes diffuse through the gills. Blood wastes are filtered by the kidneys .
Saltwater fish tend to lose water because of osmosis . Their kidneys return water to the body. The reverse happens in freshwater fish : they tend to gain water osmotically. Their kidneys produce dilute urine for excretion. Some fish have specially adapted kidneys that vary in function, allowing them to move from freshwater to saltwater.
Main article: Fish scale
The scales of fish originate from the mesoderm (skin); they may be similar in structure to teeth.
SENSORY AND NERVOUS SYSTEM
Dorsal view of the brain of the rainbow trout
Central Nervous System
Connecting the forebrain to the MIDBRAIN is the diencephalon (in the diagram, this structure is below the optic lobes and consequently not visible). The diencephalon performs functions associated with hormones and homeostasis . The pineal body lies just above the diencephalon. This structure detects light, maintains circadian rhythms, and controls color changes.
The midbrain or mesencephalon contains the two optic lobes . These are very large in species that hunt by sight, such as rainbow trout and cichlids .
The HINDBRAIN or metencephalon is particularly involved in swimming and balance. The cerebellum is a single-lobed structure that is typically the biggest part of the brain. Hagfish and lampreys have relatively small cerebellae, while the mormyrid cerebellum is massive and apparently involved in their electrical sense .
The BRAIN STEM or myelencephalon is the brain's posterior. As well as controlling some muscles and body organs, in bony fish at least, the brain stem governs respiration and osmoregulation .
Most fish possess highly developed sense organs. Nearly all daylight fish have color vision that is at least as good as a human's (see vision in fishes ). Many fish also have chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears, many fish may not hear very well. Most fish have sensitive receptors that form the lateral line system , which detects gentle currents and vibrations, and senses the motion of nearby fish and prey. Some fish, such as catfish and sharks, have the Ampullae of Lorenzini , organs that detect weak electric currents on the order of millivolt. Other fish, like the South American electric fishes Gymnotiformes , can produce weak electric currents, which they use in navigation and social communication.
Main article: Vision in fishes
Vision is an important sensory system for most species of fish. Fish
eyes are similar to those of terrestrial vertebrates like birds and
mammals, but have a more spherical lens . Their retinas generally have
both rods and cones (for scotopic and photopic vision ), and most
species have colour vision . Some fish can see ultraviolet and some
can see polarized light . Amongst jawless fish , the lamprey has
well-developed eyes, while the hagfish has only primitive eyespots .
See also: Sensory systems in fish § Hearing
Hearing is an important sensory system for most species of fish. Fish sense sound using their lateral lines and their ears .
Capacity For Pain
Further information: Pain in fish
Experiments done by William Tavolga provide evidence that fish have pain and fear responses. For instance, in Tavolga's experiments, toadfish grunted when electrically shocked and over time they came to grunt at the mere sight of an electrode.
In 2003, Scottish scientists at the
University of Edinburgh and the
Roslin Institute concluded that rainbow trout exhibit behaviors often
associated with pain in other animals.
Professor James D. Rose of the University of Wyoming claimed the study was flawed since it did not provide proof that fish possess "conscious awareness, particularly a kind of awareness that is meaningfully like ours". Rose argues that since fish brains are so different from human brains, fish are probably not conscious in the manner humans are, so that reactions similar to human reactions to pain instead have other causes. Rose had published a study a year earlier arguing that fish cannot feel pain because their brains lack a neocortex . However, animal behaviorist Temple Grandin argues that fish could still have consciousness without a neocortex because "different species can use different brain structures and systems to handle the same functions."
Most fish move by alternately contracting paired sets of muscles on either side of the backbone. These contractions form S-shaped curves that move down the body. As each curve reaches the back fin, backward force is applied to the water, and in conjunction with the fins, moves the fish forward. The fish's fins function like an airplane's flaps. Fins also increase the tail's surface area, increasing speed. The streamlined body of the fish decreases the amount of friction from the water. Since body tissue is denser than water, fish must compensate for the difference or they will sink. Many bony fish have an internal organ called a swim bladder that adjusts their buoyancy through manipulation of gases. A great white shark off Isla Guadalupe
Although most fish are exclusively ectothermic , there are exceptions.
Certain species of fish maintain elevated body temperatures. Endothermic teleosts (bony fish) are all in the suborder Scombroidei and include the billfishes , tunas, and one species of "primitive" mackerel (Gasterochisma melampus). All sharks in the family Lamnidae – shortfin mako, long fin mako, white, porbeagle, and salmon shark – are endothermic, and evidence suggests the trait exists in family Alopiidae (thresher sharks ). The degree of endothermy varies from the billfish , which warm only their eyes and brain, to bluefin tuna and porbeagle sharks who maintain body temperatures elevated in excess of 20 °C above ambient water temperatures. See also gigantothermy . Endothermy, though metabolically costly, is thought to provide advantages such as increased muscle strength, higher rates of central nervous system processing, and higher rates of digestion .
In terms of spermatogonia distribution, the structure of teleosts
testes has two types: in the most common, spermatogonia occur all
along the seminiferous tubules , while in atherinomorph fish they are
confined to the distal portion of these structures.
Oogonia development in teleosts fish varies according to the group, and the determination of oogenesis dynamics allows the understanding of maturation and fertilization processes. Changes in the nucleus , ooplasm, and the surrounding layers characterize the oocyte maturation process.
Postovulatory follicles are structures formed after oocyte release; they do not have endocrine function, present a wide irregular lumen, and are rapidly reabsorbed in a process involving the apoptosis of follicular cells. A degenerative process called follicular atresia reabsorbs vitellogenic oocytes not spawned. This process can also occur, but less frequently, in oocytes in other development stages.
Some fish, like the California sheephead , are hermaphrodites , having both testes and ovaries either at different phases in their life cycle or, as in hamlets , have them simultaneously.
Over 97% of all known fish are oviparous , that is, the eggs develop outside the mother's body. Examples of oviparous fish include salmon , goldfish , cichlids , tuna , and eels . In the majority of these species, fertilisation takes place outside the mother's body, with the male and female fish shedding their gametes into the surrounding water. However, a few oviparous fish practice internal fertilization, with the male using some sort of intromittent organ to deliver sperm into the genital opening of the female, most notably the oviparous sharks, such as the horn shark , and oviparous rays, such as skates . In these cases, the male is equipped with a pair of modified pelvic fins known as claspers .
Marine fish can produce high numbers of eggs which are often released into the open water column. The eggs have an average diameter of 1 millimetre (0.039 in).
Egg of lamprey *
Egg of catshark (mermaids\' purse ) *
Egg of bullhead shark *
Egg of chimaera *
Ovary of fish (Corumbatá).
The newly hatched young of oviparous fish are called larvae . They are usually poorly formed, carry a large yolk sac (for nourishment), and are very different in appearance from juvenile and adult specimens. The larval period in oviparous fish is relatively short (usually only several weeks), and larvae rapidly grow and change appearance and structure (a process termed metamorphosis ) to become juveniles. During this transition larvae must switch from their yolk sac to feeding on zooplankton prey, a process which depends on typically inadequate zooplankton density, starving many larvae.
In ovoviviparous fish the eggs develop inside the mother's body after internal fertilization but receive little or no nourishment directly from the mother, depending instead on the yolk . Each embryo develops in its own egg. Familiar examples of ovoviviparous fish include guppies , angel sharks , and coelacanths .
Some species of fish are viviparous . In such species the mother retains the eggs and nourishes the embryos. Typically, viviparous fish have a structure analogous to the placenta seen in mammals connecting the mother's blood supply with that of the embryo. Examples of viviparous fish include the surf-perches , splitfins , and lemon shark . Some viviparous fish exhibit oophagy , in which the developing embryos eat other eggs produced by the mother. This has been observed primarily among sharks, such as the shortfin mako and porbeagle , but is known for a few bony fish as well, such as the halfbeak Nomorhamphus ebrardtii. Intrauterine cannibalism is an even more unusual mode of vivipary, in which the largest embryos eat weaker and smaller siblings. This behavior is also most commonly found among sharks, such as the grey nurse shark , but has also been reported for Nomorhamphus ebrardtii.
Aquarists commonly refer to ovoviviparous and viviparous fish as livebearers .
Main article: Fish diseases and parasites
Like other animals, fish suffer from diseases and parasites. To prevent disease they have a variety of defenses. Non-specific defenses include the skin and scales, as well as the mucus layer secreted by the epidermis that traps and inhibits the growth of microorganisms . If pathogens breach these defenses, fish can develop an inflammatory response that increases blood flow to the infected region and delivers white blood cells that attempt to destroy pathogens. Specific defenses respond to particular pathogens recognised by the fish's body, i.e., an immune response . In recent years, vaccines have become widely used in aquaculture and also with ornamental fish, for example furunculosis vaccines in farmed salmon and koi herpes virus in koi .
Some species use cleaner fish to remove external parasites. The best known of these are the Bluestreak cleaner wrasses of the genus Labroides found on coral reefs in the Indian and Pacific oceans. These small fish maintain so-called "cleaning stations" where other fish congregate and perform specific movements to attract the attention of the cleaners. Cleaning behaviors have been observed in a number of fish groups, including an interesting case between two cichlids of the same genus, Etroplus maculatus, the cleaner, and the much larger Etroplus suratensis.
Immune organs vary by type of fish. In the jawless fish (lampreys and hagfish), true lymphoid organs are absent. These fish rely on regions of lymphoid tissue within other organs to produce immune cells. For example, erythrocytes , macrophages and plasma cells are produced in the anterior kidney (or pronephros ) and some areas of the gut (where granulocytes mature.) They resemble primitive bone marrow in hagfish. Cartilaginous fish (sharks and rays) have a more advanced immune system. They have three specialized organs that are unique to Chondrichthyes ; the epigonal organs (lymphoid tissue similar to mammalian bone) that surround the gonads, the Leydig\'s organ within the walls of their esophagus, and a spiral valve in their intestine. These organs house typical immune cells (granulocytes, lymphocytes and plasma cells). They also possess an identifiable thymus and a well-developed spleen (their most important immune organ) where various lymphocytes , plasma cells and macrophages develop and are stored. Chondrostean fish (sturgeons, paddlefish, and bichirs) possess a major site for the production of granulocytes within a mass that is associated with the meninges (membranes surrounding the central nervous system.) Their heart is frequently covered with tissue that contains lymphocytes, reticular cells and a small number of macrophages . The chondrostean kidney is an important hemopoietic organ; where erythrocytes, granulocytes, lymphocytes and macrophages develop.
Like chondrostean fish, the major immune tissues of bony fish (or teleostei ) include the kidney (especially the anterior kidney), which houses many different immune cells. In addition, teleost fish possess a thymus, spleen and scattered immune areas within mucosal tissues (e.g. in the skin, gills, gut and gonads). Much like the mammalian immune system, teleost erythrocytes, neutrophils and granulocytes are believed to reside in the spleen whereas lymphocytes are the major cell type found in the thymus. In 2006, a lymphatic system similar to that in mammals was described in one species of teleost fish, the zebrafish . Although not confirmed as yet, this system presumably will be where naive (unstimulated) T cells accumulate while waiting to encounter an antigen .
B and T lymphocytes bearing immunoglobulins and T cell receptors , respectively, are found in all jawed fishes. Indeed, the adaptive immune system as a whole evolved in an ancestor of all jawed vertebrate.
IUCN Red List
Overfishing is a major threat to edible fish such as cod and tuna . Overfishing eventually causes population (known as stock ) collapse because the survivors cannot produce enough young to replace those removed. Such COMMERCIAL EXTINCTION does not mean that the species is extinct, merely that it can no longer sustain a fishery.
One well-studied example of fishery collapse is the Pacific sardine
Sadinops sagax caerulues fishery off the
The main tension between fisheries science and the fishing industry is that the two groups have different views on the resiliency of fisheries to intensive fishing. In places such as Scotland, Newfoundland, and Alaska the fishing industry is a major employer, so governments are predisposed to support it. On the other hand, scientists and conservationists push for stringent protection, warning that many stocks could be wiped out within fifty years.
See also: Environmental impact of fishing
A key stress on both freshwater and marine ecosystems is habitat degradation including water pollution , the building of dams, removal of water for use by humans, and the introduction of exotic species. An example of a fish that has become endangered because of habitat change is the pallid sturgeon , a North American freshwater fish that lives in rivers damaged by human activity.
Introduction of non-native species has occurred in many habitats. One of the best studied examples is the introduction of Nile perch into Lake Victoria in the 1960s. Nile perch gradually exterminated the lake's 500 endemic cichlid species. Some of them survive now in captive breeding programmes, but others are probably extinct. Carp , snakeheads , tilapia , European perch , brown trout , rainbow trout , and sea lampreys are other examples of fish that have caused problems by being introduced into alien environments.
IMPORTANCE TO HUMANS
Throughout history, humans have utilized fish as a food source .
Historically and today, most fish protein has come by means of
catching wild fish. However, aquaculture, or fish farming, which has
been practiced since about 3,500 BCE. in
Catching fish for the purpose of food or sport is known as fishing , while the organized effort by humans to catch fish is called a fishery . Fisheries are a huge global business and provide income for millions of people. The annual yield from all fisheries worldwide is about 154 million tons, with popular species including herring , cod , anchovy , tuna , flounder , and salmon . However, the term fishery is broadly applied, and includes more organisms than just fish, such as mollusks and crustaceans , which are often called "fish" when used as food.
Recreational fishing is fishing for pleasure or competition; it can be contrasted with commercial fishing , which is fishing for profit. The most common form of recreational fishing is done with a rod , reel , line , hooks and any one of a wide range of baits . Angling is a method of fishing, specifically the practice of catching fish by means of an "angle" (hook). Anglers must select the right hook, cast accurately, and retrieve at the right speed while considering water and weather conditions, species, fish response, time of the day, and other factors.
The astrological symbol Pisces is based on a constellation of the same name , but there is also a second fish constellation in the night sky, Piscis Austrinus .
FISH OR FISHES
Though often used interchangeably, in biology these words have
TRUE FISH AND FINFISH
* In biology, the term fish is most strictly used to describe any animal with a backbone that has gills throughout life and has limbs, if any, in the shape of fins . Many types of aquatic animals with common names ending in "fish" are not fish in this sense ; examples include shellfish , cuttlefish , starfish , crayfish and jellyfish . In earlier times, even biologists did not make a distinction—sixteenth century natural historians classified also seals , whales , amphibians , crocodiles , even hippopotamuses , as well as a host of aquatic invertebrates, as fish. * In fisheries, the term fish is used as a collective term, and includes mollusks , crustaceans and any aquatic animal which is harvested. * The strict biological definition of a fish, above, is sometimes called a true fish. True fish are also referred to as finfish or fin fish to distinguish them from other aquatic life harvested in fisheries or aquaculture.
SHOAL OR SCHOOL
Main article: Shoaling and schooling These goldband fusiliers are schooling because their swimming is synchronised
A random assemblage of fish merely using some localised resource such as food or nesting sites is known simply as an aggregation. When fish come together in an interactive, social grouping, then they may be forming either a shoal or a school depending on the degree of organisation. A shoal is a loosely organised group where each fish swims and forages independently but is attracted to other members of the group and adjusts its behaviour, such as swimming speed, so that it remains close to the other members of the group. Schools of fish are much more tightly organised, synchronising their swimming so that all fish move at the same speed and in the same direction. Shoaling and schooling behaviour is believed to provide a variety of advantages.
* Cichlids congregating at lekking sites form an aggregation. * Many minnows and characins form shoals. * Anchovies, herrings and silversides are classic examples of schooling fish.
While the words "school" and "shoal" have different meanings within
biology, the distinctions are often ignored by non-specialists who
treat the words as synonyms . Thus speakers of British English
commonly use "shoal" to describe any grouping of fish, and speakers of
Angling (sport fishing)
* ^ Goldman, K.J. (1997). "Regulation of body temperature in the
white shark, Carcharodon carcharias". Journal of Comparative
Physiology. B Biochemical Systemic and Environmental Physiology. 167
(6): 423–429. doi :10.1007/s003600050092 . Retrieved 12 October
* ^ Carey, F.G.; Lawson, K.D. (February 1973). "Temperature
regulation in free-swimming bluefin tuna". Comparative Biochemistry
and Physiology A. 44 (2): 375–392. doi :10.1016/0300-9629(73)90490-8
* ^ "FishBase".
FishBase . April 2015. Retrieved 29 August 2015.
* ^ "Monster fish crushed opposition with strongest bite ever".
Smh.com.au . 30 November 2006. Retrieved 26 February 2013.
* ^ G. Lecointre & H. Le Guyader, 2007, The Tree of Life: A
Phylogenetic Classification, Harvard University Press Reference
* ^ Romer, A.S . & T.S. Parsons. 1977. The
Vertebrate Body. 5th ed.
Saunders, Philadelphia. (6th ed. 1985)
* ^ Benton, M. J. (1998) The quality of the fossil record of
vertebrates. Pp. 269–303, in Donovan, S. K. and Paul, C. R. C.
(eds), The adequacy of the fossil record, Fig. 2. Wiley, New York, 312
* ^ Shigehiro Kuraku, Daisuke Hoshiyama, Kazutaka Katoh, Hiroshi
Suga, Takashi Miyata (1999) Monophyly of Lampreys and Hagfishes
Supported by Nuclear DNA–Coded Genes J Mol Evol (1999) 49:729–735
* ^ J. Mallatt, J. Sullivan (1998) 28S and 18S rDNA sequences
support the monophyly of lampreys and hagfishes Molecular Biology and
Evolution V 15, Issue 12, pp 1706–1718
* ^ Nelson 2006 , pp. 4–5
* ^ Nelson 2006 , p. 3
* ^ Nelson 2006 , p. 2
* ^ A B Helfman, Collette Larry S. Roberts; Allan L. Larson (2001).
Integrated Principles of Zoology. McGraw-Hill Publishing Co. ISBN
* ^ Helfman, Collette & Facey 1997 , p. 103
* ^ Helfman, Collette & Facey 1997 , pp. 53–57
* ^ Helfman, Collette & Facey 1997 , pp. 33–36
* ^ Martin, K.L.M. (2014). Beach-Spawning Fishes: Reproduction in
an Endangered Ecosystem. CRC Press. ISBN 978-1482207972 .
* ^ Froese, Rainer and Pauly, Daniel, eds. (2006). "Periophthalmus
FishBase . November 2006 version.
* ^ Planet Catfish. "Cat-eLog: Heptapteridae: Phreatobius:
Phreatobius sp. (1)". Planet Catfish. Retrieved 26 November 2006.
* ^ Henderson, P.A.; and I. Walker (1990). "Spatial organization
and population density of the fish community of the litter banks
within a central Amazonian blackwater stream". Journal of Fish
Biology. 37: 401–411. CS1 maint: Uses authors parameter (link )
* ^ Aldemaro, R., ed. (2001). The Biology of Hypogean Fishes.
Developments in environmental biology of fishes. 21. ISBN
* ^ Estudo das Espécies Ícticas do Parque Estadual do Cantão,
fish species survey of Cantão (in Portuguese)
* ^ A B "Modifications of the Digestive Tract for Holding Air in
Loricariid and Scoloplacid Catfishes" (PDF).
Copeia (3): 663–675.
1998. doi :10.2307/1447796 . Retrieved 25 June 2009.
* ^ Setaro, John F. (1999). Circulatory System. Microsoft Encarta
* ^ A B C D E F G H I J K Helfman, Collette & Facey 1997 , pp.
* ^ Helfman, Collette & Facey 1997 , p. 191
* ^ Orr, James (1999). Fish. Microsoft Encarta 99. ISBN
* ^ Albert, J.S., and W.G.R. Crampton. 2005.
electrogenesis. pp. 431–472 in The Physiology of Fishes, 3rd
Edition. D.H. Evans and J.B. Claiborne (eds.). CRC Press.
* ^ Sciences, Journal of Undergraduate Life. "Appropriate maze
methodology to study learning in fish" (PDF). Archived from the
original (PDF ) on 25 June 2009. Retrieved 28 May 2009.
* ^ Campbell, Neil A. ; Reece, Jane B. (2005). Biology (Seventh
* Eschmeyer, William N.; Fong, Jon David (2013). "Catalog of
* Helfman, G.; Collette, B.; Facey, D.; Bowen, B. (2009). The
Diversity of Fishes: Biology, Evolution, and Ecology (2nd ed.).
Wiley-Blackwell. ISBN 978-1-4051-2494-2 .
* Moyle, Peter B. (1993) Fish: An Enthusiast\'s Guide University of
Wikimedia Commons has media related to FISH , ACTINOPTERYGII , MARINE AQUARIUM FISH and FRESHWATER AQUARIUM FISH