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Axolotl
leucistic specimen
Conservation status
Critically endangered
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Amphibia Order: Caudata Family: Ambystomatidae Genus: Ambystoma Species: A. mexicanum
Binomial name
Ambystoma mexicanum (Shaw, 1789)

The Axolotl (or ajolote) (Ambystoma mexicanum) is the best-known of the Mexican neotenic mole salamanders belonging to the Tiger Salamander complex. Larvae of this species fail to undergo metamorphosis, so the adults remain aquatic and gilled. The species originates from the lake underlying Mexico City. Axolotls are used extensively in scientific research due to their ability to regenerate most body parts, ease of breeding, and large embryos. They are commonly kept as pets in the United States, Great Britain (under the spelling Axlotl), Australia, Japan (where they are sold under the name Wooper Rooper (ウーパールーパー, Ūpā Rūpā^?)), and other countries. Image File history File links Question_book-3. ... Personally taken photo of an axolotl. ... Leucism is characterized by reduced pigmentation, resulting in an individual with white or brighter patches of fur, plumage or skin than in the typical representative of the species. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn3. ... . ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... For other uses, see Amphibian (disambiguation). ... Families Salamander is the common name applied to approximately 350 amphibian vertebrates with slender bodies, short legs, and long tails (order Caudata or Urodela). ... Genera   Ambystoma   Rhyacosiredon Mole salamanders (family Ambystomatidae) are secretive salamanders which spend most of their adult life underground or under cover. ... Genera   Ambystoma   Rhyacosiredon Mole salamanders (family Ambystomatidae) are secretive salamanders which spend most of their adult life underground or under cover. ... This article does not cite any references or sources. ... George Shaw. ... Neoteny describes a process by which paedomorphism is achieved, and is a subject studied in the field of developmental biology. ... Genera   Ambystoma   Rhyacosiredon Mole salamanders (family Ambystomatidae) are secretive salamanders which spend most of their adult life underground or under cover. ... Binomial name Ambystoma tigrinum Green, 1825 Subspecies A. tigrinum tigrinum The Tiger Salamander (Ambystoma tigrinum) is a species of Mole Salamander. ... A cicada in the process of shedding. ... External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits, as they are in most fishes. ... Nickname: Motto: Capital en movimiento Location of Mexico City in south central Mexico Coordinates: , Country Federal entity Boroughs The 16 delegaciones Founded c. ... Look up regeneration in Wiktionary, the free dictionary. ...

Axolotls should not be confused with waterdogs, the larval stage of the closely related Tiger Salamanders (Ambystoma tigrinum and Ambystoma mavortium), which is widespread in much of North America which also occasionally become neotenic, nor with mudpuppies (Necturus spp.), fully aquatic salamanders which are not closely related to the axolotl but which bear a resemblance. Binomial name Ambystoma tigrinum Green, 1825 Subspecies A. tigrinum tigrinum The Tiger Salamander (Ambystoma tigrinum) is a species of Mole Salamander. ... Genera Necturus Proteus The Mudpuppies or Waterdogs are a family of aquatic salamanders. ...

Description

A sexually-mature adult axolotl, at age 18–24 months, ranges in length from 15–45 cm (6–18 inches), although a size close to 23 cm (9 inches) is most common and greater than 30 cm (12 inches) is rare. Axolotls possess features typical of salamander larvae, including external gills and a caudal fin extending from behind the head to the vent. Their heads are wide, and their eyes are lidless. Their limbs are underdeveloped and possess long, thin digits. Males are identified by their swollen cloacas lined with papillae, while females are noticeable for their wider bodies full of eggs. Three pairs of external gill stalks (rami) originate behind their heads and are used to move oxygenated water. The external gill rami are lined with filaments (fimbriae) to increase surface area for gas exchange. Four gill slits lined with gill rakers are hidden underneath the external gills. Axolotls have barely visible vestigial teeth which would have developed during metamorphosis. The primary method of feeding is by suction, during which their rakers interlock to close the gill slits. External gills are used for respiration, although buccal pumping (gulping air from the surface) may also be used in order to provide oxygen to their lungs. Axolotls have four different colours, two naturally occurring colours and two mutants. The two naturally occurring colours are wildtype (Varying shades of brown usually with spots) and melanoid (black). The two mutants colours are leucistic (pale pink with black eyes) and albino (golden, tan or pale pink with pink eyes). In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, urinary, and genital tracts of certain animal species. ... Buccal pumping is a method of respiration using the throat muscles. ...

Habitat and ecology

The axolotl is native only to Lake Xochimilco and Lake Chalco in central Mexico. Unfortunately for the axolotl, Lake Chalco no longer exists, as it was drained by humans to avoid periodic flooding, and Lake Xochimilco remains a diminished glimpse of its former self, existing mainly as canals. The water temperature in Xochimilco rarely rises above 20°C (68°F), though it may fall to 6 or 7°C (43°F) in the winter, and perhaps lower. The wild population has been put under heavy pressure by the growth of Mexico City. Axolotls are also sold as food in Mexican markets, and were a staple in the Aztec diet. They are currently listed by CITES as an endangered species, and by IUCN as critically endangered in the wild, with a decreasing population. Lake Xochimilco is a lake located in the Mexican Basin, this water body was an important element for the human development in central Mexico. ... Lake Chalco is a lake that was located in the mexican basin. ... Lake Chalco is a lake that was located in the mexican basin. ... Lake Xochimilco is a lake located in the Mexican Basin, this water body was an important element for the human development in central Mexico. ... Nickname: Motto: Capital en movimiento Location of Mexico City in south central Mexico Coordinates: , Country Federal entity Boroughs The 16 delegaciones Founded c. ... The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international agreement between Governments, drafted as a result of a resolution adopted in 1963 at a meeting of members of the World Conservation Union (IUCN). ... The Siberian Tiger is a subspecies of tiger that are critically endangered. ... The World Conservation Union or International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ... An endangered species is a species whose population is so small that it is in danger of becoming extinct. ...

Axolotls are members of the Ambystoma tigrinum (Tiger salamander)-complex, along with all other Mexican species of Ambystoma. Their habitat is like that of most neotenic species - a high altitude body of water surrounded by a risky terrestrial environment. These conditions are thought to favor neoteny. However, a terrestrial population of Mexican Tiger Salamanders occupies and breeds in the Axolotl's habitat. Neoteny describes a process by which paedomorphism is achieved, and is a subject studied in the field of developmental biology. ...

Axolotl's neoteny

Axolotls exhibit a property called neoteny, meaning that they reach sexual maturity without undergoing metamorphosis. Many species within the Axolotl's genus are either entirely neotenic or have neotenic populations. In the axolotl, metamorphic failure is caused by a lack of thyroid stimulating hormone, which is used to induce the thyroid to produce thyroxine in transforming salamanders. The genes responsible for neoteny in laboratory animals may have been identified, however they are not linked in wild populations, suggesting artificial selection is the cause of complete neoteny in laboratory and pet axolotls. Neoteny describes a process by which paedomorphism is achieved, and is a subject studied in the field of developmental biology. ... A Pieris rapae larva An older Pieris rapae larva A Pieris rapae pupa A Pieris rapae adult Metamorphosis is a process in biology by which an individual physically develops after birth or hatching, and involves significant change in form as well as growth and differentiation. ... Thyroid-stimulating hormone (also known as TSH or thyrotropin) is a hormone produced by thyrotrope cells in the anterior pituitary gland which regulates the endocrine function of the thyroid gland. ... Thyroxine, or 3:5,3:5 tetra­iodothyronine (often abbreviated as T4) is the major hormone secreted by the follicular cells of the thyroid gland. ... This Chihuahua mix and Great Dane show the wide range of dog breed sizes created using artificial selection. ...

Unlike some other neotenic salamanders (Sirens and Necturus), Axolotls can be induced to metamorphose by an injection of iodine (used in the production of thyroid hormones) or by shots of thyroxine hormone. Another method for inducing transformation, though one that is very rarely successful, involves removing an axolotl in good condition to a shallow tank in a vivarium and slowly reducing the water level so that the axolotl has difficulty submerging. It will then, over a period of weeks, slowly metamorphose into an adult salamander. During transformation, the air in the vivarium must remain moist, and the maturing axolotl sprayed with a fine mist of pure water. The odds of the animal being able to metamorphose via this method are extremely small, and most attempts at inducing metamorphosis lead to death. This is likely due to the strong genetic basis for neoteny in laboratory and pet axolotls, which means that few captive animals have the ability to metamorphose on their own. Spontaneous metamorphosis has been known to occur very rarely, but attempts to do so artificially are best left to trained scientists. Artificial metamorphosis also dramatically shortens the axolotl's lifespan, if they survive the process. A neotenic axolotl will live an average of 10–15 years (though an individual in Paris is credited with achieving 25 years), while a metamorphosed specimen will scarcely live past the age of five. The adult form resembles a terrestrial Mexican Tiger Salamander, but has several differences, such as longer toes, which support its status as a separate species. Genera   Pseudobranchus   Siren The Sirens are a family of aquatic salamanders. ... Necturus is a genus of aquatic salamander only found in the eastern United States. ... For the record label, see Iodine Recordings. ... Thyroxine, or 3:5,3:5 tetra­iodothyronine (often abbreviated as T4) is the major hormone secreted by the follicular cells of the thyroid gland. ... Two glass terrariums with plants. ... Binomial name Dugès, 1888 Synonyms Ambystoma lacustris Taylor & Smith, 1945 Ambystoma subsalsum Taylor, 1943 The Plateau Tiger Salamander or Salamandra (Ambystoma velasci) is a species of mole salamander in the Ambystomatidae family. ...

Use as a model organism

Six adult axolotls (including a leucistic specimen) were shipped from Mexico City to the "Jardin des Plantes" in Paris in 1863. Unaware of their neoteny, Auguste Duméril was surprised when, instead of the axolotl, he found in the vivarium a new species, similar to the salamander. This discovery was the starting point of research about neoteny. It is not certain that Mexican Tiger salamanders were not included in the original shipment. The surviving neotenes are thought to be the ancestors of the majority of pet and laboratory axolotls in existence. The Jardin des Plantes is the main botanical garden in France. ... Auguste Duméril. ...

Vilem Laufberger of Germany used thyroid hormone injections to induce an axolotl to grow into a terrestrial adult salamander. The experiment was repeated by the Englishman Julian Huxley, who was unaware the experiment had already been done, using ground thyroid hormones. Since then, experiments have been done often with injections of iodine or various thyroid hormones used to induce metamorphosis. For other uses, see Salamander (disambiguation). ... Sir Julian Sorell Huxley, FRS (June 22, 1887 – February 14, 1975) was a English biologist, author, Humanist and internationalist, known for his popularisations of science in books and lectures. ...

Today, the axolotl is still used in research as a model organism and large numbers are bred in captivity. Axolotls are especially easy to breed compared to other salamanders in their family, which are almost never captive bred due to the demands of terrestrial life. One attractive feature for research is the large and easily manipulated embryo, which allows viewing of the full development of a vertebrate. Axolotls are used in heart defect studies due to the presence of a mutant gene that causes heart failure in embryos. Since the embryos survive almost to hatching with no heart function, the defect is very observable. The presence of several color morphs has also been extensively studied. A model organism is a species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. ... For other uses, see Embryo (disambiguation). ...

The feature of the salamander that attracts most attention is its healing ability: the axolotl does not heal by scarring and is capable of the regeneration of entire lost appendages in a period of months, and, in certain cases, more vital structures. Some have indeed been found restoring the less vital parts of their brains. They can also readily accept transplants from other individuals, including eyes and parts of the brain — restoring these alien organs to full functionality. In some cases, axolotls have been known to repair a damaged limb as well as regenerating an additional one, ending up with an extra appendage that makes them attractive to pet owners as a novelty. In metamorphosed individuals, however, the ability to regenerate is greatly diminished. The axolotl is therefore used as a model for the development of limbs in vertebrates. In biology, regeneration is an organisms ability to replace body parts. ...

Feeding

The axolotl is carnivorous, consuming small prey such as worms, insects, and small fish in the wild. In captivity, they can be fed a variety of readily available foods, including trout and salmon pellets, frozen or live bloodworms, earthworms, and waxworms on occasion. Axolotls also enjoy beef liver and sometimes small prawns. Beef heart is sometimes recommended, but is not a good choice for the animal as mammal proteins are not readily digestible. Small juveniles can be fed with Daphnia or brine shrimp until old enough for the larger foodstuffs. Axolotls locate food by smell, and will "snap" at any potential meal, sucking the food into their stomachs with vacuum force. This is why other animals may not be housed with axolotls (excluding adults with adults) as anything smaller will invariably end up in their mouths — even siblings. Fish can also nibble an axolotl's gill stalks and appendages while it is asleep, leading to infection. Blood worm or bloodworm is an ambiguous term and can refer to: A midge larva The polychaete Glycera This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Families   Acanthodrilidae   Ailoscolecidae   Alluroididae   Almidae   Criodrilidae   Eudrilidae   Exxidae   Glossoscolecidae   Lumbricidae   Lutodrilidae   Megascolecidae   Microchaetidae   Ocnerodrilidae   Octochaetidae   Sparganophilidae Earthworm is the common name for the largest members of the Oligochaeta (which is either a class or subclass depending on the author) in the phylum Annelida. ... Waxworms are the larvae of the wax moth. ... Species Subgenus Daphnia Subgenus Hyalodaphnia D. galeata Subgenus Ctenodaphnia Daphnia are small, mostly planktonic, crustaceans, between 0. ... For non-zoological information on this animal as a pet, see Sea-Monkey. ...

Captive care and husbandry

Ambystoma mexicanum, albino specimens.

Axolotls live at temperatures of 14–20°C (54–68°F), preferably 17–18°C (62–64°F). Lower temperatures slow down their metabolism, although temperatures around 10°C (50°F) are a panacea when it comes to treating disease. Higher temperatures can lead to stress and increased appetite; use of a cooling aggregate is strongly recommended. Tapwater should be treated with a dechlorinator before the animal is introduced into it, as chlorine is harmful. Axolotls should be kept in a stable pH environment of between 6.5 to 8, with a slightly alkaline pH of 7.3 to 7.6 being the ideal. A single typical axolotl should be kept in a normal 10 U.S. gallon tank (44 litres) with around 150 mm (6 inches) of water. A power filter or underwater filter run by an airpump can be used, though water flow should be kept to a minimum to avoid stressing the animal. A 20% water change should be done every week, with debris being siphoned from the bottom. Small gravel should be avoided, as the axolotl can mistakenly ingest the rocks, leading to stress and gas. Floating plants should be provided for juveniles as a hiding place, and small caves should likewise be provided for adults. No light is necessary as axolotls are nocturnal. Axolotls will spend a majority of the time on the bottom of the tank (floating is a sign of stress and illness), so design accordingly. Image File history File links common name: Axolotl Photo by Vsion 2005 File links The following pages link to this file: Axolotl User:Vsion/Gallery ... Image File history File links common name: Axolotl Photo by Vsion 2005 File links The following pages link to this file: Axolotl User:Vsion/Gallery ... Albinism is a genetic condition resulting in a lack of pigmentation in the eyes, skin and hair. ... A dechlorinator is a chemical additive that removes chlorine or chloramine from water. ...

In laboratory colonies, adult axolotls are often housed three to a one gallon container, and water changes are performed more regularly. Salts, such as Holtfreter's solution, are usually added to the water to prevent infection.

Cultural references

This article or section contains too many minor or trivial fictional references. Mere trivia, or references unimportant to the overall plot of a work of fiction, should be deleted. See also what Wikipedia is.

• Aldous Huxley's After Many a Summer was inspired by his brother's experiments with Axolotls.
• Argentine writer Julio Cortazar wrote a short story, Axolotl, in which the narrator, having long been obsessed with axolotls, becomes one.
• It was often used in the early years of Mad magazine as a running gag and in-joke (along with others like Furshlugginer and Potrzebie). For instance, this parody of Wordsworth's "I Wandered Lonely as a Cloud":

I wandered lonely as a clod,

Just picking up old rags and bottles,

When onward on my way I plod,

I saw a host of axolotls.

• Bhob Stewart's blog Potrzebie is subtitled "Masquerade of the Albino Axolotls."
• The axolotl is mentioned in the musical Children of Eden by Stephen Schwartz. In the aptly titled song called "The Naming", Adam and Eve run through a long list of animals that start with the letter "a", at one point mentioning the axolotl.
• The fictional creatures Wooper and Quagsire, as well as Mudkip from the Pokémon franchise are all based on axolotls.
• The central character (played by Bruno Ganz) in Alain Tanner's 1983 film In the White City is compared to an Axolotl because of his state of (spiritual) immobility.
• The fictional Dr. Shrunk from Animal Crossing: Wild World is an axolotl. If talked to, he will grant you emotions to use in the game.
• In Rene Daumal's book A Night of Serious Drinking there is an extended metaphor relating mankind to axolotls. He states that while an axolotl may be forced into maturity, man cannot be forced but must desire such a transformation.
• The band Hum titled a song Afternoon With the Axolotls on their 1997 album Downward is Heavenward.
• The webcomic 5ideways has a character that is referred to as "Axolotl"
• In one page of the webcomic Dresden Codak, the main character, Kimiko “Thunderbolt” Ross tells the story of how in 1863, the French zoologist, Auguste Duméril was sent a shipment of Axolotls which had gone through the metamorphose process en route.
• The artist 'Nautilis' has a 2002 electronica album entitled 'Are You an Axolotl' out on the record label 'Planet Mu'
• The children's book, "Is it Hairy? Is it Scary?" features the Axolotl as one of the animals in the book.
• The character Lycoris from the .hack//"Legend of the Twilight" manga has a haistyle based on the Axolotl, or as in mentioned in the manga, "Wooper Looper".
• In Negima!?, Satomi Hasake's Suka form is an axolotl.
• There is a song called "Axolotl" on Proto-Kaw's album, Before Became After.
• Anna Reeves's short film The Imploding Self: A Journey Through the Life of Fergus McLafferty (1995) [1] features its title character with a pet axolotl, being allergic to all conventional pets, and he gradually starts to resemble one more and more. When he learns of axolotls being used as food in a country he plans to visit, he screams "cannibalism" and cancels his trip.

Image File history File links Broom_icon. ... Look up trivia in Wiktionary, the free dictionary. ... Look up Plot in Wiktionary, the free dictionary. ... Aldous Leonard Huxley (July 26, 1894 – November 22, 1963) was an English writer and one of the most prominent members of the famous Huxley family. ... After Many a Summer is a novel by Aldous Huxley. ... Julio Cortázar (August 26, 1914 - February 12, 1984) was an Argentine intellectual and author of several experimental novels and many short stories. ... Mad is an American humor magazine founded by editor Harvey Kurtzman and publisher William Gaines in 1952. ... The running gag is a popular hallmark of comic and serious forms of entertainment. ... An in joke is a joke whose humour is clear only to those people who are in a group that has some prior knowledge (not known by the whole population) that makes the joke humorous. ... Potrzebie is a seemingly nonsensical word (actually Polish), popularized by its use as a running gag in the early issues of Mad not long after the comic book began in 1952. ... In contemporary usage, a parody (or lampoon) is a work that imitates another work in order to ridicule, ironically comment on, or poke some affectionate fun at the work itself, the subject of the work, the author or fictional voice of the parody, or another subject. ... William Wordsworth (April 7, 1770 – April 23, 1850) was a major English romantic poet who, with Samuel Taylor Coleridge, helped launch the Romantic Age in English literature with their 1798 joint publication, Lyrical Ballads. ... Wikisource has original text related to this article: I Wandered Lonely as a Cloud The Daffodils is an 1804 poem by William Wordsworth. ... Bhob Stewart is an American writer, editor and artist who has written for a variety of publications over a span of five decades. ... Children of Eden is a two-act musical play with music and lyrics by Stephen Schwartz based on a book by John Caird. ... Stephen Lawrence Schwartz (born March 6, 1948) is an American musical theater lyricist and composer. ... Wooper ) is one of the 493[]   fictional species of Pokémon creatures from the multi-billion-dollar[1] Pokémon media franchise – a collection of video games, anime, manga, books, trading cards and other media created by Satoshi Tajiri. ... Quagsire ) is one of the 493   fictional species of Pokémon from the Pokémon Franchise – a series of video games, anime, manga, books, trading cards and other media created by Satoshi Tajiri. ... Mudkip , Mizugorou in original Japanese language versions) is one of the 493 fictional species of Pokémon creatures from the multi-billion-dollar[1] Pokémon media franchise – a collection of video games, anime, manga, books, trading cards and other media created by Satoshi Tajiri. ... The official Pokémon logo. ... (born March 22, 1941 in Zurich) is a Swiss actor. ... Alain Tanner (born 6 December 1929 in Geneva) is a Swiss film director. ... René Daumal (1908 - 1944) was a French surrealist writer, philosopher and poet, born on March 16, 1908 in Boulzicourt, Ardennes, France. ... A Night of Serious Drinking is an allegorical novel by the French surrealist writer René Daumal detailing what is ostensibly an extremely simple plot in which the narrator overly imbibes alcohol; what unfolds however is a novel which explores the extremities of heaven and hell. ... Hum are a space rock/Alternative Rock band from Champaign, Illinois. ... Downward is Heavenward is the fourth and most recent studio album by the Champaign, Illinois space rock band Hum. ... An editor has expressed a concern that the subject of the article does not satisfy the notability guideline for Web content. ... Auguste Duméril. ... .hack (pronounced dot-hack) is a multimedia franchise primarily created by Bandai. ... This article or section does not cite any references or sources. ... Proto-Kaw (proto=early version of) ( kaw=Native American word for Kansas) has come around full circle in their music careers and again are performing concerts and recording. ... Reunion CD from the original Kansas II lineup, under their new name of Proto-Kaw. ... Cannibal redirects here. ...

References

See also

• Tiger Salamander
• Barred Tiger Salamander
• Neoteny

Binomial name Ambystoma tigrinum Green, 1825 Subspecies A. tigrinum tigrinum The Tiger Salamander (Ambystoma tigrinum) is a species of Mole Salamander. ... Binomial name Ambystoma mavortium Baird, 1850 The Barred Tiger Salamander (Ambystoma mavortium) is a species of salamander found from southwestern Canada in British Columbia, Alberta, Saskatchewan and Manitoba, south through the western United States to Texas, and northern Mexico. ... Neoteny describes a process by which paedomorphism is achieved, and is a subject studied in the field of developmental biology. ...

External links

Wikimedia Commons has media related to:

Ambystoma mexicanum

• Axolotls as Pets
• Axolotl.org
• Short narrated film about the Axolotl
• A website devoted to the salamander family, Caudata.org