Walking fish
Encyclopedia
Walking
Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...
fish, is a general term that refers to fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
that are able to travel over land for extended periods of time. The term may also be used for some other cases of nonstandard fish locomotion
Fish locomotion
The prevailing type of fish locomotion is swimming in water. In addition, some fish can "walk", i.e., move over land, burrow in mud, and glide through the air.-Swimming:Fish swim by exerting force against the surrounding water...
, e.g., when describing fish "walking" along the sea floor
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
.
Types of walking fish
Most commonly this term is applied to amphibious fishAmphibious fish
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. These fish use a range of terrestrial locomotory modes, such as...
. Able to spend longer times out of water, these fish may use a number of means of locomotion
Animal locomotion
Animal locomotion, which is the act of self-propulsion by an animal, has many manifestations, including running, swimming, jumping and flying. Animals move for a variety of reasons, such as to find food, a mate, or a suitable microhabitat, and to escape predators...
, including springing, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
-like lateral undulation, and tripod
Tripod fish
Tripod fish, Bathypterois grallator, are a deep-sea benthic fish found at lower latitudes. They are now relatively well known from photographs and submersible observations...
-like walking. The mudskipper
Mudskipper
Mudskippers are members of the subfamily Oxudercinae , within the family Gobiidae . They are completely amphibious fish, fish that can use their pectoral fins to walk on land...
s are probably the best land-adapted of contemporary fish and are able to spend days moving about out of water and can even climb mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s, although to only modest heights. The Climbing gourami
Climbing gourami
The Anabantidae are a family of perciform fish commonly called the climbing gouramies or climbing perches. As labyrinth fishes, they possess a labyrinth organ, a structure in the fish's head which allows them to breathe atmospheric oxygen...
is often specifically referred to as a "walking fish", although it does not actually "walk", but rather moves in a jerky way by supporting itself on the extended edges of its gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
plates and pushing itself by its fins and tail. Some reports indicate that it can also climb trees.
There are a number of fish that are less adept at actual walking, such as the walking catfish
Walking catfish
The walking catfish, Clarias batrachus, is a species of freshwater airbreathing catfish found primarily in Southeast Asia, so named for its ability to "walk" across dry land, to find food or suitable environments...
. Despite being known for "walking on land", this fish usually wriggles and may use its pectoral fins to aid in its movement. Walking Catfish have a respiratory system
Respiratory system
The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...
that allows them to live out of water for several days. Some are invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. A notorious case in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
is the Northern snakehead
Northern snakehead
The Northern snakehead is a type of snakehead fish native to China, Russia, North Korea and South Korea. In the United States, the fish is considered to be a highly invasive species...
. Polypterids
Bichir
The bichirs are a family, Polypteridae, of archaic-looking ray-finned fishes, the sole family in the order Polypteriformes.All species occur in freshwater habitats in tropical Africa and the Nile River system, mainly swampy, shallow floodplains and estuaries.-Anatomy and appearance:Bichirs are...
have rudimentary lungs and can also move about on land, though rather clumsily.
There are some species of fish that can "walk" along the sea floor but not on land; one such animal is the flying gurnard
Dactylopteridae
The flying gurnards are a family, Dactylopteridae, of marine fish notable for their greatly enlarged pectoral fins. As they cannot literally fly, an alternative name preferred by some authors is helmet gurnards...
(it does not actually fly, and should not be confused with flying fish). The batfishes of the Ogcocephalidae
Ogcocephalidae
Ogcocephalidae is a family of bottom-dwelling, specially adapted fish. They are sometimes referred to as batfishes or anglerfishes. They are found in deep, lightless waters of the Atlantic, Indian and western Pacific Oceans....
family (not to be confused with Batfish of Ephippidae
Ephippidae
Ephippidae is the fish family containing the spadefishes. There are about eight genera, with a total of 20 species, mostly marine. The most well-known species are probably those in the reef-dwelling genus Platax, the batfishes, which are kept as aquarium fish. They are spade-shaped, laterally...
) are also capable of walking along the sea floor.
Axolotl
The axolotl , Ambystoma mexicanum, is a neotenic salamander, closely related to the Tiger Salamander. Larvae of this species fail to undergo metamorphosis, so the adults remain aquatic and gilled. It is also called ajolote...
, an aquatic salamander
Salamander
Salamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...
native to Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, is colloquially known as the "Mexican walking fish", although it is not a fish, but an amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
.
Evolutionary link
Tetrapod
Tetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
s (four-legged animals). The theory of evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
suggests that life originated in the oceans and later moved onto land, and paleontologists have long been looking for a missing evolutionary link between ocean-living and land-living animals. Of recent finds, reported in Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
(April 2006) is Tiktaalik roseae
Tiktaalik
Tiktaalik is a genus of extinct sarcopterygian from the late Devonian period, with many features akin to those of tetrapods . It is an example from several lines of ancient sarcopterygian "fish" developing adaptations to the oxygen-poor shallow-water habitats of its time, which led to the...
, which has many features of wrist, elbow, and neck that are akin to those of tetrapods. It belonged to a group of lobe-finned fish
Sarcopterygii
The Sarcopterygii or lobe-finned fishes – sometimes considered synonymous with Crossopterygii constitute a clade of the bony fishes, though a strict classification would include the terrestrial vertebrates...
called Rhipidistia
Rhipidistia
The Rhipidistia were lobe-finned fishes that are the ancestors of the tetrapods. Taxonomists traditionally considered the Rhipidistia a subgroup of Crossopterygii that described a group of fish that lived during the Devonian consisting of the Porolepiformes and Osteolepiformes...
, which according to some recent theories were the ancestors of all tetrapods.
Popular culture
Parodies of the ichthys symbol
The ichthys symbol, or "Jesus fish", typically used to proclaim an affiliation with or affinity for Christianity, is sometimes a subject of satire, especially when adorning the bumpers or trunks of automobiles. Most such ornaments are adhesive badges made of chrome-colored plastic...
", a bumper sticker
Bumper sticker
A bumper sticker is an adhesive label or sticker with a message, intended to be attached to the bumper of an automobile and to be read by the occupants of other vehicles - although they are often stuck onto other objects...
parody of the Ichthys
Ichthys
Ichthys, from Koine Greek: , is the Greek word for "fish"....
, a symbol of Christianity
Christian symbolism
Christian symbolism invests objects or actions with an inner meaning expressing Christian ideas. Christianity has borrowed from the common stock of significant symbols known to most periods and to all regions of the world. Religious symbolism is effective when it appeals to both the intellect and...
.
In the Treehouse of Horror V
Treehouse of Horror V
"Treehouse of Horror V" is the sixth episode of The Simpsons sixth season and the fifth episode in the Treehouse of Horror series. It premiered on October 30, 1994, and features three short stories called The Shinning, Time and Punishment, and Nightmare Cafeteria...
segment Time and Punishment Homer
Homer Simpson
Homer Jay Simpson is a fictional character in the animated television series The Simpsons and the patriarch of the eponymous family. He is voiced by Dan Castellaneta and first appeared on television, along with the rest of his family, in The Tracey Ullman Show short "Good Night" on April 19, 1987...
accidentally kills a walking fish by sitting on it.
Also in Judge Me Tender
Judge Me Tender
"Judge Me Tender" is the twenty-third episode and season finale of The Simpsons twenty-first season. It is the 464th episode for the series and originally premiered in the United States on May 23, 2010, on Fox Broadcasting Company. In the episode, Moe discovers his talent for judging in...
one of Ned
Ned Flanders
Nedward "Ned" Flanders, Jr. is a recurring fictional character in the animated television series The Simpsons. He is voiced by Harry Shearer, and first appeared in the series premiere episode "Simpsons Roasting on an Open Fire". He is the next door neighbor to the Simpson family and is generally...
's fish walks out of the tank.