California Giant Salamander
Encyclopedia
The California Giant Salamander (Dicamptodon ensatus) is a species of salamander
in the Dicamptodontidae family.
It is endemic to the United States
. The species name once additionally included individuals now belonging to the species D. aterrimus (Idaho Giant Salamander
) and D. tenebrosus (Coastal Giant Salamander
), under the common name Pacific Giant Salamander
, which now refers to the genus and family. The Pacific giant salamander (D. ensatus) was thought to consist of three geographic populations, an Idaho
isolate, a group in northern California
and a group in Oregon
and Washington. In 1989 genetic studies showed that the D. ensatus populations consisted of three subspecies: the Idaho Giant Salamander
(Dicamptodon aterrimus) in Idaho, and two highly divergent species with a narrow hybrid zone in California, the Coastal Giant Salamander
(Dicamptodon tenebrosus) (ranging from northern California to Washington) and the California Giant Salamander
(Dicamptodon ensatus) (ranging from Santa Cruz County
to Mendocino County).
A fourth species of Dicamptodon, Cope's Giant Salamander
(D. copei), lives on the Olympic Peninsula
, Washington.
Its natural habitat
s are temperate forest
s, river
s, freshwater lake
s, and freshwater marsh
es.
Terrestrial adults search for prey such as snails, slugs, other invertebrates, small mice, shrews, possibly reptiles, and other amphibians under surface objects and in tunnels underground, whereas aquatic adults and larvae eat aquatic invertebrates, fish, and other amphibians. California Giant Salamanders are preyed upon by the American Water Shrew
(Sorex palustris) and the Western Aquatic Garter Snake
(Thamnophis couchi).
and lives up to 6500 feet (1,981.2 m) primarily in damp, coastal forests including Coast Douglas fir (Pseudotsuga menziesii var. menziesii), California redwood (Sequoia sempervirens) in both montane and valley-foothill riparian habitats. They tend to be common when they occur. The adult terrestrial form is found under surface litter and in tunnels underground, while the adult aquatic and larval forms are found mainly in cool, rocky streams and occasionally in lakes and ponds. It is found in two (possibly three) isolated regions. The first range includes Sonoma
and Marin
Counties, southwestern Lake County
, western Glenn County
, and southern Mendocino County. The other documented region is south of the San Francisco Bay from central San Mateo County to southern Santa Cruz County
plus western Santa Clara County. The California Giant Salamander doesn't occur in the East Bay, forming a gap between these two populations. There is an unconfirmed sight record from Big Sur
in Monterey County, approximately 75 miles (100 km) to the south of the documented population in the Santa Cruz area.
continue to grow into an adult and become sexually mature without losing their external gills. This process is called neoteny
. Adult-sized neotenes have a uniform brown coloring on their heads, sides, and backs and retained external gills which allow them to live in perennial streams as aquatic adults.
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...
in the Dicamptodontidae family.
It is endemic to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The species name once additionally included individuals now belonging to the species D. aterrimus (Idaho Giant Salamander
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, , D. copei and D...
) and D. tenebrosus (Coastal Giant Salamander
Coastal Giant Salamander
The Coastal Giant Salamander is a species of salamander in the Dicamptodontidae family . It is endemic to the United States and Canada. There are three closely related species to this taxon: D. ensatus , D. copei , and D...
), under the common name Pacific Giant Salamander
Pacific giant salamander
Pacific giant salamanders are a family of large salamanders.The family includes only a single genus, Dicamptodon. The genus was formerly thought to contain two species, Cope's Giant Salamander on the Olympic Peninsula, Washington, and the Pacific giant salamander Pacific giant salamanders...
, which now refers to the genus and family. The Pacific giant salamander (D. ensatus) was thought to consist of three geographic populations, an Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
isolate, a group in northern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and a group in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and Washington. In 1989 genetic studies showed that the D. ensatus populations consisted of three subspecies: the Idaho Giant Salamander
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, , D. copei and D...
(Dicamptodon aterrimus) in Idaho, and two highly divergent species with a narrow hybrid zone in California, the Coastal Giant Salamander
Coastal Giant Salamander
The Coastal Giant Salamander is a species of salamander in the Dicamptodontidae family . It is endemic to the United States and Canada. There are three closely related species to this taxon: D. ensatus , D. copei , and D...
(Dicamptodon tenebrosus) (ranging from northern California to Washington) and the California Giant Salamander
California Giant Salamander
The California Giant Salamander is a species of salamander in the Dicamptodontidae family.It is endemic to the United States. The species name once additionally included individuals now belonging to the species D. aterrimus and D...
(Dicamptodon ensatus) (ranging from Santa Cruz County
Santa Cruz County
Santa Cruz County is the name of two counties in the United States:* Santa Cruz County, Arizona* Santa Cruz County, California...
to Mendocino County).
A fourth species of Dicamptodon, Cope's Giant Salamander
Cope's Giant Salamander
Cope's Giant Salamander is a species of salamander in the Dicamptodontidae family. It reaches between 12.4–19.1 cm . The salamander resembles Pacific Giant Salamander larvae, but it never transforms to a terrestrial stage. It is smaller overall with a narrower head and shorter limbs...
(D. copei), lives on the Olympic Peninsula
Olympic Peninsula
The Olympic Peninsula is the large arm of land in western Washington state of the USA, that lies across Puget Sound from Seattle. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Puget Sound. Cape Alava, the westernmost point in the contiguous...
, Washington.
Its natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s are temperate forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s, river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s, freshwater lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, and freshwater marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es.
Description
The adult California Giant Salamander can reach up 17-30.5 cm (6.7-12 inches) in total length. Like all salamanders, the California Giant Salamander has four toes on the front feet and five toes on the back feet. The California Giant Salamander's tail is around 40 percent of the total length of the salamander and is laterally compressed. The head, back, and sides of the salamander have a marbled or reticulate pattern of dark blotches on a light brown or brassy-colored background. They have a broad head with a shovel-like snout and a fold of skin across the throat called the gular fold. The eyes 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.Terrestrial adults search for prey such as snails, slugs, other invertebrates, small mice, shrews, possibly reptiles, and other amphibians under surface objects and in tunnels underground, whereas aquatic adults and larvae eat aquatic invertebrates, fish, and other amphibians. California Giant Salamanders are preyed upon by the American Water Shrew
American Water Shrew
The American Water Shrew or Northern Water Shrew, is a large North American shrew found in aquatic habitats. Some sources include the Glacier Bay Water Shrew, S. alaskanus, within this species....
(Sorex palustris) and the Western Aquatic Garter Snake
Garter snake
The Garter snake is a Colubrid snake genus common across North America, ranging from Alaska and Canada to Central America. It is the single most widely distributed genus of reptile in North America. The garter snake is also the Massachusettsstate reptile.There is no real consensus on the...
(Thamnophis couchi).
Reproduction and Development
The California Giant Salamander breeds from March to May, with egg-laying peaking in May. Eggs are concealed several feet below the surface in cold, slowly flowing water often beneath rocks and coarse woody debris in stream bottoms. Adults sometimes stay near their nests. Larvae may lose their external gills and transform to terrestrial adults after 1 to 2 years. In permanently perennial streams, adults may retain their gills and become aquatic adults. (See Neotenes below.)Range
The California Giant Salamander is endemic to Northern CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and lives up to 6500 feet (1,981.2 m) primarily in damp, coastal forests including Coast Douglas fir (Pseudotsuga menziesii var. menziesii), California redwood (Sequoia sempervirens) in both montane and valley-foothill riparian habitats. They tend to be common when they occur. The adult terrestrial form is found under surface litter and in tunnels underground, while the adult aquatic and larval forms are found mainly in cool, rocky streams and occasionally in lakes and ponds. It is found in two (possibly three) isolated regions. The first range includes Sonoma
Sonoma County, California
Sonoma County, located on the northern coast of the U.S. state of California, is the largest and northernmost of the nine San Francisco Bay Area counties. Its population at the 2010 census was 483,878. Its largest city and county seat is Santa Rosa....
and Marin
Marin County, California
Marin County is a county located in the North San Francisco Bay Area of the U.S. state of California, across the Golden Gate Bridge from San Francisco. As of 2010, the population was 252,409. The county seat is San Rafael and the largest employer is the county government. Marin County is well...
Counties, southwestern Lake County
Lake County, California
Lake County is a county located in the north central portion of the U.S. state of California, north of the San Francisco Bay Area. It takes its name from Clear Lake, the dominant geographic feature in the county and the largest natural lake wholly within California...
, western Glenn County
Glenn County, California
Glenn County is in the California Central Valley. As of 2010, it had a population of 28,122. The county seat is the city of Willows.-History:Glenn County was formed in 1891 from parts of Colusa County. It was named for Dr. Hugh J...
, and southern Mendocino County. The other documented region is south of the San Francisco Bay from central San Mateo County to southern Santa Cruz County
Santa Cruz County, California
Santa Cruz County is a county located on the Pacific coast of the U.S. state of California, on the California Central Coast. The county forms the northern coast of the Monterey Bay. . As of the 2010 U.S. Census, its population was 262,382. The county seat is Santa Cruz...
plus western Santa Clara County. The California Giant Salamander doesn't occur in the East Bay, forming a gap between these two populations. There is an unconfirmed sight record from Big Sur
Big Sur
Big Sur is a sparsely populated region of the Central Coast of California where the Santa Lucia Mountains rise abruptly from the Pacific Ocean. The name "Big Sur" is derived from the original Spanish-language "el sur grande", meaning "the big south", or from "el país grande del sur", "the big...
in Monterey County, approximately 75 miles (100 km) to the south of the documented population in the Santa Cruz area.
Neotenes
Some California Giant Salamander larvaLarva
A larva 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...
continue to grow into an adult and become sexually mature without losing their external gills. This process is called neoteny
Neoteny
Neoteny , also called juvenilization , is one of the two ways by which paedomorphism can arise. Paedomorphism is the retention by adults of traits previously seen only in juveniles, and is a subject studied in the field of developmental biology. In neoteny, the physiological development of an...
. Adult-sized neotenes have a uniform brown coloring on their heads, sides, and backs and retained external gills which allow them to live in perennial streams as aquatic adults.