The coastal giant salamander (''Dicamptodon tenebrosus'') is a species of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...

in the family Dicamptodontidae (Pacific giant salamanders). It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

of North America. There are three closely related species to this taxon: ''D. ensatus'' (

California giant salamander The California giant salamander (''Dicamptodon ensatus'') is a species of salamander in the family Ambystomatidae. ''Dicamptodon ensatus'' is endemic to California, in the western United States. The species once additionally included individuals ...

), ''D. copei'' (

Cope's giant salamander Cope's giant salamander (''Dicamptodon copei'') is a species of salamander in the family Dicamptodontidae, the Pacific giant salamanders.Behler, J. L. and F. W. King. (1979) ''National Audubon Society Field Guide to Reptiles and Amphibians'', Kno ...

), and ''D. aterrimus'' (

Idaho giant salamander The Idaho giant salamander, ''Dicamptodon aterrimus'', is a species of salamander. There are three closely related species to this taxon: ''D. ensatus'', (California giant salamander), ''D. copei'' (Cope's giant salamander) and ''D. tenebrosus'' ...

Description

The coastal giant salamander can reach up to 34 cm (13 inches) in total length, making it the largest terrestrial salamander in North America. The coastal giant salamander has stout limbs with four toes on the front feet and five toes on the back feet. The species tail is around 40 percent of the total length of the salamander and is laterally compressed. The head, back, and sides have a marbled or reticulate pattern of dark blotches on a light brown or brassy-colored background. The head is broad with a shovel-like snout and a fold of skin across the throat called the gular fold. The

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

s are medium in size and have a brass-flecked iris and a large black pupil. This species is one of the few salamanders capable of vocalizing.

Life history

A female coastal giant salamander will lay her eggs in moderate to slow flowing mountain streams under rocks and crevasses, hatching in early to mid spring. The coastal giant salamander, being a member of the genus ''Dicamptodon'', exhibits two distinctive phases within its life; an aquatic larval stage with filamentous gills and an elongated tail with a caudal fin (similar to that of a tadpole), and a terrestrial adult form losing their caudal fin and filamentous gills, and instead developing robust legs and a pair of internal lungs.

Neoteny

Some coastal giant salamander

larvae 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. The ...

continue to grow into adults and become sexually mature without losing their 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 are ...

s. This process is called

neoteny Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared ...

. Neoteny is particularly common in the British Columbia populations. Adult-sized neotenes have a uniform brown coloring on their heads, sides, and backs.

Behavior

Activity level

Terrestrial adult coastal giant salamanders spend most of their time underground in burrows, emerging to reproduce and forage on rainy and humid nights.

Foraging and diet

Adult coastal giant salamanders, like most of the genus ''Dicamptodon'', are opportunistic feeders feeding on anything they can fit in their mouth. This may include, but is not limited to; slugs, insects, worms and other invertebrates as well as small vertebrates such as small rodents, snakes, and other giant salamanders. In the larval stage, coastal giant salamanders will feed on small macroinvertebrates such as insect larvae as well as small fish and mollusks. Both adult and larval coastal salamanders have been recorded consuming other individuals of the same species.

Defense

When threatened an adult coastal giant salamander will arch its back and lash its tail forward. Coastal giant salamanders excrete toxins through their skin which will cause nausea if consumed. Adult coastal giant salamanders can produce a painful bite.

Range

The coastal giant salamander is

to the Pacific Northwest, found in Northern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

, and southern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Habitat

Aquatic stages are found in clear, cool or cold, well-oxygenated streams, and sometimes also in mountain lakes and ponds. Metamorphosed adults are found in humid forests (under rocks and logs, etc.), near mountain streams, or rocky shores of mountain lakes.

Conservation

Pacific giant salamanders are protected from being killed or collected under the Wildlife Act in

References

{{Taxonbar, from=Q2277209 Dicamptodon Amphibians of Canada Amphibians of the United States Fauna of California Natural history of Oregon Natural history of Washington (state) Amphibians described in 1852 Taxa named by Spencer Fullerton Baird Taxa named by Charles Frédéric Girard