The barred tiger salamander or western tiger salamander (''Ambystoma mavortium'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

mole salamander The mole salamanders ( genus ''Ambystoma'') are a group of advanced salamanders endemic to North America. The group has become famous due to the presence of the axolotl (''A. mexicanum''), widely used in research due to its paedomorphosis, an ...

that lives in lower

western Canada Western Canada, also referred to as the Western provinces, Canadian West or the Western provinces of Canada, and commonly known within Canada as the West, is a Canadian region that includes the four western provinces just north of the Canada� ...

, the

western United States The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the We ...

and northern Mexico.

Description

The barred tiger salamander typically grows from but it can grow to long at the most and is one of the largest species of salamander in North America. It has a broad head and a sturdy body. The color is variable across its range. The dorsal surface is grey, dark brown or black with bars and spots of muddy yellow giving it a tiger-like coloring. The ventral surface varies from light to dark. Larvae have alternating dark and light blotches on the centre of the dorsal surface and pale stripes running along the sides.

Behavior

Primarily

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, barred tiger salamanders are opportunistic feeders, and will often eat anything they can catch, including various insects, slugs, and earthworms. They are primarily terrestrial as adults, but their juvenile,

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

l stage is entirely aquatic, having external

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

s. Breeding takes place during most months of the year. The eggs are laid in water and the developing larvae are exclusively aquatic.

Cannibalism

There are two main feeding morphologies for barred tiger salamanders, typical and cannibalistic. The cannibalistic form is characterized by large vomerine teeth, slim bodies and wider heads. The teeth give a better hold on prey, and the wider heads allow for eating larger organisms. In some areas, these include

fathead minnow Fathead minnow (''Pimephales promelas''), also known as fathead or tuffy, is a species of temperate freshwater fish belonging to the genus '' Pimephales'' of the cyprinid family. The natural geographic range extends throughout much of North A ...

s. Since the two species have similar diets, eating a competitor also reduces demand on their shared food. Cannibalistic tiger salamanders tend to metamorphosize earlier than the typical ones. Most often, cannibals are found in drier areas and shallow, more competive waters, making earlier metamorphosis advantageous.

Subspecies

The five recognized

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

of ''Ambystoma mavortium'' are: * Gray barred tiger salamander, ''A. m. diaboli'' ) * Barred tiger salamander, ''A. m. mavortium'' () * Blotched tiger salamander, ''A. m. melanostictum'' () * Arizona tiger salamander, ''A. m. nebulosum'' () * Sonoran tiger salamander, ''A. m. stebbinsi'' () Grey barred tiger salamander Manitoba

Distribution and habitat

The barred tiger salamander lives in western Canada and the western half of the United States, but infrequently in California and Nevada. In Canada it is known from British Columbia, Alberta, Saskatchewan and Manitoba. Its range in the United States extends to the southernmost tip of Texas, but no further east than the Dakotas and Oklahoma. It has been introduced into southern Arizona because its larvae are used as fish bait. It is a mainly terrestrial species, living in lowland deciduous forests, coniferous forests and woodlands. It also inhabits open fields, rough ground, upland meadows, grasslands, deserts, semideserts and streams.

Status

The Sonoran tiger salamander was classified as an endangered species in 1997, due to increased human activity causing degradation and fragmentation of its habitat. It is also threatened by various disease outbreaks triggered by species not native to Arizona. Some introduced animals, such as crayfish, prey on it.

In captivity

Tiger salamanders are frequently kept in captivity; they mostly hide and ambush their prey. It is illegal to sell adults in most parts of the United States. Their large size allows for ease of feeding, and their hardy nature makes them excellent captives. Their larval stage is often sold as fishing bait, marketed as "mud puppies" or "water dogs".

Symbol

The tiger salamander is the state amphibian of

Kansas Kansas () is a U.S. state, state in the Midwestern United States, Midwestern United States. Its Capital city, capital is Topeka, Kansas, Topeka, and its largest city is Wichita, Kansas, Wichita. Kansas is a landlocked state bordered by Nebras ...

. The second grade class of 1993 of O‑K Elementary in Wichita, Kansas, petitioned the governor; students Timothy Boyd and Kristofer Voorhees presented the initial idea for a state amphibian to their teacher. It is also the state amphibian of

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...

after being recognized by the Colorado legislature on March 16, 2012.

References

Unused sources

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External links

* * {{Taxonbar, from=Q2615538 Mole salamanders Amphibians described in 1850 Amphibians of Canada Amphibians of Mexico Amphibians of the United States Fauna of the Western United States Symbols of Colorado Symbols of Kansas Taxa named by Spencer Fullerton Baird