Amphibious fish are fish that are able to leave water for extended periods of time. About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of terrestrial locomotory modes, such as lateral undulation, tripod-like walking (using paired fins and tail), and jumping. Many of these locomotory modes incorporate multiple combinations of pectoral, pelvic and tail fin movement.
Many ancient fish had lung-like organs, and a few, such as the lungfish, still do. Some of these ancient "lunged" fish were the ancestors of tetrapods. However, in most recent fish species these organs evolved into the swim bladders, which help control buoyancy. Having no lung-like organs, modern amphibious fish and many fish in oxygen-poor water use other methods such as their gills or their skin to breathe air. Amphibious fish may also have eyes adapted to allow them to see clearly in air, despite the refractive index differences between air and water.
The American eel (Anguilla rostrata) is a facultative catadromous fish found on the eastern coast of North America. Eels (Anguilla spp.) are fish belonging to the elopomorph superorder, a group of phylogenetically ancient teleosts. The American eel has a slender snakelike body that is covered with a mucous layer, which makes the eel appear to be naked and slimy despite the presence of minute scales. A long dorsal fin runs from the middle of the back and is continuous with a similar ventral fin. Pelvic fins are absent, and relatively small pectoral fin can be found near the midline, followed by the head and gill-covers. Variations exist in coloration, from olive green, brown shading to greenish-yellow and light gray or white on the belly. Eels from clear water are often lighter than those from dark, tannic acid streams.The eel lives in fresh water and estuaries and only leaves these habitats to enter the Atlantic Ocean to start its spawning migration to the Sargasso Sea. Spawning takes place far offshore where the eggs hatch. The female can lay up to 4 million buoyant eggs a year, and dies after egg-laying.
After the eggs hatch and the early-stage larvae develop into leptocephali, the young eels move toward North America where they metamorphose into glass eels and enter freshwater systems where they grow as yellow eels until they begin to mature.
The American eel is found along the Atlantic coast including Chesapeake Bay and the Hudson River and as far north as the St. Lawrence River region. It is also present in the river systems of the eastern Gulf of Mexico and in some areas further south. Like all anguillid eels, American eels hunt predominantly at night, and during the day they hide in mud, sand or gravel very close to shore, at depths of roughly 5 to 6 feet. They feed on crustaceans, aquatic insects, small insects, and probably any aquatic organisms that they can find and eat.American eels are economically important in various areas along the East Coast as bait for fishing for sport fishes such as the striped bass, or as a food fish in some areas. Their recruitment stage, the glass eel, are also caught and sold for use in aquaculture, although this is now restricted in most areas.
Eels were once an abundant species in rivers, and were an important fishery for aboriginal people. The construction of hydroelectric dams has blocked their migrations and locally extirpated eels in many watersheds. For example, in Canada, the vast numbers of eels in the St. Lawrence and Ottawa Rivers have dwindled.Amphibious
Amphibious means able to use either land or water. In particular it may refer to:
Amphibious (film), a 2010 film
Amphibious aircraft, an aircraft capable of landing on either water or land
Amphibious vehicle, a vehicle capable of being driven on both land and water
Amphibious warfare, warfare carried out on both land and waterClimbing gourami
The Anabantidae are a family of perciform fish commonly called the climbing gouramies or climbing perches. The family includes about 34 species. As labyrinth fishes, they possess a labyrinth organ, a structure in the fish's head which allows it to breathe atmospheric oxygen. Fish of this family are commonly seen gulping at air at the surface of the water. The air is held in a structure called the suprabranchial chamber, where oxygen diffuses into the bloodstream via the respiratory epithelium covering the labyrinth organ. This therefore allows the fish to move small distances across land.
Of the four genera, Anabas is found from South Asia (they are called (Tamil: பனையேறி கெண்டை (Panaieri Kendai) chemballi (Malayalam: urulan sugu/Karippidi) in Kerala, kau (odia) in Odisha, India, kawaiya in Sri Lanka,Bangla: ক্ই মাছ(koi mach), east to China and Southeast Asia. The remaining three genera are all restricted to Africa. They are primarily freshwater fishes and only very rarely are found in brackish water. Parental care is varied; Anabas and Ctenopoma simply abandon their eggs, Microctenopoma species produce bubblenests like their relatives in the Osphronemidae, and Sandelia lays their eggs on the substrate.
Climbing gouramis are so named due to their ability to "climb" out of water and "walk" short distances. Even though it has not been reliably observed, some authors have mentioned about them having a tree climbing ability. Their method of terrestrial locomotion uses the gill plates as supports, and the fish pushes itself using its fins and tail.Eel catfish
The eel catfish (Channallabes apus) is an airbreathing catfish found in the muddy swamps of the tropics of Central Africa. The fish grows to 32.7 cm long TL (12.9 inches) and is notable for the ability to propel itself out of the water to catch prey.
The thin eel-shaped body of C. apus is black or dark brown, with widely spaced spines. A suprabranchial organ, formed by tree-like structures from the second and fourth gill arches, allows the eel catfish to take in oxygen directly from the air for short periods. Its eyes are small and hidden, and it lacks pectoral fins entirely. Like many anguilliform clariids, its jaw muscles are hypertrophic, a modification that has been linked to increased bite force.The eel catfish hunts both in and out of the water, having a different method for each. In water, C. apus sucks water and food into its mouth. To catch food on land, the eel catfish lifts the front of its body up, and bends its mouth down on the prey. Its specially adapted spine allows it to do so without weight-bearing pectoral fins.European eel
The European eel (Anguilla anguilla) is a species of eel, a snake-like, catadromous fish. They can reach a length of 1.5 m (4 ft 11 in) in exceptional cases, but are normally around 60–80 cm (2.0–2.6 ft), and rarely reach more than 1 m (3 ft 3 in).
Eels have been important sources of food both as adults (including the famous jellied eels of East London) and as glass eels. Glass-eel fishing using basket traps has been of significant economic value in many river estuaries on the western seaboard of Europe.
While the species' lifespan in the wild has not been determined, captive specimens have lived over 80 years. According to a report in The Local, a specimen lived 155 years in the well of a family home in Brantevik, a fishing village in southern Sweden.Euryhaline
Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (Poecilia sphenops) which can live in fresh water, brackish water, or salt water. The green crab (Carcinus maenas) is an example of a euryhaline invertebrate that can live in salt and brackish water. Euryhaline organisms are commonly found in habitats such as estuaries and tide pools where the salinity changes regularly. However, some organisms are euryhaline because their life cycle involves migration between freshwater and marine environments, as is the case with salmon and eels.
The opposite of euryhaline organisms are stenohaline ones, which can only survive within a narrow range of salinities. Most freshwater organisms are stenohaline, and will die in seawater, and similarly most marine organisms are stenohaline, and cannot live in fresh water.Fear of fish
Fear of fish or ichthyophobia ranges from cultural phenomena such as fear of eating fish, fear of touching raw fish, or fear of dead fish, up to irrational fear (specific phobia). Galeophobia is the fear specifically of sharks.Freshwater fish
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.
41.24% of all known species of fish are found in fresh water. This is primarily due to the rapid speciation that the scattered habitats make possible. When dealing with ponds and lakes, one might use the same basic models of speciation as when studying island biogeography.Ichthyology
Ichthyology (from Greek: ἰχθύς, ikhthys, "fish"; and λόγος, logos, "study"), also known as fish science, is the branch of zoology devoted to the study of fish. This includes bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). While a large number of species have been discovered, approximately 250 new species are officially described by science each year. According to FishBase, 33,400 species of fish had been described by October 2016.Mangrove rivulus
The mangrove killifish or mangrove rivulus, Kryptolebias marmoratus (syn. Rivulus marmoratus), is a species of fish in the Aplocheilidae family. It lives in brackish and marine waters (less frequently in fresh water) along the coasts of Florida, through the Antilles, and along the eastern and northern Atlantic coasts of Mexico, Central America and South America (south to Brazil). It has a very wide tolerance of both salinity (0—68 ‰) and temperature (12–38 °C or 54–100 °F), can survive for about two months on land, and mostly breeds by self-fertilization. It is typically found in areas with red mangrove and sometimes lives in burrows of Cardisoma guanhumi crabs.The mangrove rivulus is up to 7.5 cm (3.0 in) long, but most individuals are 1–3.8 cm (0.4–1.5 in).Overall the mangrove rivulus is widespread and not threatened, but in the United States it is considered a Species of Concern by the National Marine Fisheries Service.Mudskipper
Mudskippers are amphibious fish, presently included in the family Oxudercidae, in the subfamily Oxudercinae. There are 32 living species of mudskipper. They use their pectoral fins and pelvic fins to walk on land They typically live in intertidal habitats, and exhibit unique adaptations to this environment that are not found in most intertidal fishes, which typically survive the retreat of the tide by hiding under wet seaweed or in tide pools. Mudskippers are quite active when out of water, feeding and interacting with one another, for example, to defend their territories and court potential partners. They are found in tropical, subtropical, and temperate regions, including the Indo-Pacific and the Atlantic coast of Africa.
Oxudercinae is sometimes classified within the family Gobiidae (gobies). Recent molecular studies do not support this classification, as oxudercine gobies appear to be paraphyletic relative to amblyopine gobies (Gobiidae: Amblyopinae), thus being included in a distinct "Periophthalmus lineage", together with amblyopines. Mudskippers can be defined as oxudercine gobies that are "fully terrestrial for some portion of the daily cycle" (character 24 in Murdy, 1989). This would define the species of the genera Boleophthalmus, Periophthalmodon, Periophthalmus, and Scartelaos as "mudskippers". However, field observations of Zappa confluentus suggest that this monotypic genus should be included in the definition.Northern snakehead
The northern snakehead (Channa argus) is a species of snakehead fish native to China, Russia, North Korea, and South Korea, ranging from the Amur River to Hainan. It has been introduced to other regions, where it is considered invasive. In Europe, the first report of the species was from Czechoslovakia in 1956. In the United States, the fish is considered to be a highly invasive species. In a well-known incident, several were found in a pond in Crofton, Maryland, in June 2002, which led to major media coverage and two movies.Pacific leaping blenny
The Pacific leaping blenny (Alticus arnoldorum), also known as the leaping rockskipper, is a species of combtooth blenny (family Blenniidae) in the genus Alticus. The blennies are oviparous, and form distinct pairs when mating. Males can reach a maximum total length of 8 centimetres (3.15 inches). These fish feed primarily on benthic algae, which they consume by scraping off rocky surfaces.Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding a few—typically only one or two—monophyletic subgroups. The group is said to be paraphyletic with respect to the excluded subgroups. The arrangement of the members of a paraphyletic group is called a paraphyly. The term is commonly used in phylogenetics (a subfield of biology) and in linguistics.
The term was coined to apply to well-known taxa like Reptilia (reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor—including all extant reptiles as well as the extinct synapsids—except for mammals and birds. Other commonly recognized paraphyletic groups include fish, monkeys, and lizards.If many subgroups are missing from the named group, it is said to be polyparaphyletic. A paraphyletic group cannot be a clade, or monophyletic group, which is any group of species that includes only a common ancestor and all of its descendants. Formally, a paraphyletic group is the relative complement of one or more subclades within a clade: removing one or more subclades leaves a paraphyletic group.Periophthalmodon
Periophthalmodon is a genus of mudskippers found along muddy shores, estuaries and lower reaches of rivers in Southeast Asia, Papua New Guinea and Queensland, Australia.Semiaquatic
In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below.Terrestrial locomotion
Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the effects of gravity.
There are three basic forms of locomotion found among terrestrial animals
Legged – Moving by using appendages
Limbless locomotion – moving without legs, primarily using the body itself as a propulsive structure.
Rolling – rotating the body over the substrateWalking catfish
The walking catfish (Clarias batrachus) is a species of freshwater airbreathing catfish native to Southeast Asia. It is named for its ability to "walk" and wiggle across dry land, to find food or suitable environments. While it does not truly walk as most bipeds or quadrupeds do, it has the ability to use its pectoral fins to keep it upright as it makes a wiggling motion with snakelike movements. This fish normally lives in slow-moving and often stagnant waters in ponds, swamps, streams and rivers, flooded rice paddies or temporary pools which may dry up. When this happens, its "walking" skill allows the fish to move to other sources of water. Considerable taxonomic confusion surrounds this species and it has frequently been confused with other close relatives.Walking fish
A walking fish, or ambulatory fish, is a fish that is able to travel over land for extended periods of time. Some other modes of non-standard fish locomotion include "walking" along the sea floor, for example, in handfish or frogfish.