California giant salamander | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Family: | Ambystomatidae |
Genus: | Dicamptodon |
Species: | D. ensatus |
Binomial name | |
Dicamptodon ensatus (Eschscholtz, 1833) | |
Synonyms [1] | |
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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 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 group, a group in northern California, and a group in Oregon and Washington. [2] In 1989 genetic studies showed that the D. ensatus populations consisted of three species: 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). [3] [4] A fourth species of Dicamptodon, Cope's giant salamander (D. copei), lives on the Olympic Peninsula, Washington.
The natural habitats of D. ensatus are damp temperate forests and clear, cold freshwater streams, ponds, and lakes. [1]
The adult California giant salamander can reach 17–30.5 cm (6.7–12 inches) in total length (including tail). Like most 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 approximately 40% 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. [5]
Terrestrial adults search for prey such as snails, slugs, insects (such as beetles, caddisfly larvae, moths, and flies), other invertebrates, small mice (such as white-footed mice), shrews, possibly reptiles, and other amphibians (including reports of smaller D. ensatus) under surface objects and in tunnels. [6] Aquatic adults and larvae eat aquatic invertebrates, fish, snakes, and other amphibians. [7] California giant salamanders are preyed upon by the American water shrew (Sorex palustris) and the western aquatic garter snake (Thamnophis couchi). [8]
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. [8] (See Neotenes below.)
The California giant salamander is endemic to Northern California and lives up to 6,500 feet (2,000 m) primarily in damp, coastal forests including coast Douglas fir ( Pseudotsuga menziesii var. menziesii) and California coast redwood ( Sequoia sempervirens ) in both montane and valley-foothill riparian habitats. They tend to be common where they occur. The adult terrestrial form is found under surface litter and in tunnels, while the adult aquatic and larval forms are found mainly in cool, rocky streams and occasionally in lakes and ponds. [8]
It is found in two (possibly three) isolated regions. The first range includes Sonoma, Napa, 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 does not occur in the East Bay, forming a gap between these two populations. [4] [9] 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. [4]
Some California giant salamander larvae continue to grow into adults 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. [8]
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes. All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura, Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems. Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
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 extant salamander families are grouped together under the order Urodela from the group Caudata. Urodela is a scientific Latin term based on the Ancient Greek οὐρά δήλη: ourà dēlē "conspicuous tail". Caudata is the Latin for "tailed ones", from cauda : "tail".
The mole salamanders are a group of advanced salamanders endemic to North America. The group has become famous due to the presence of the axolotl, widely used in research due to its paedomorphosis, and the tiger salamander which is the official amphibian of many US states, and often sold as a pet.
Ambystomatidae is a family of salamanders belonging to the Suborder Salamandroidea in the class Amphibia. It contains two genera, Ambystoma and Dicamptodon. Ambystoma contains 32 species and are distributed widely across North America, while Dicamptodon contains four species restricted to the Pacific Northwest. These salamanders are mostly terrestrial and eat invertebrates, although some species are known to eat smaller salamanders. They can be found throughout the US and some areas of Canada in damp forests or plains. This family contains some of the largest terrestrial salamanders in the world, the tiger salamander and the coastal giant salamander. Some species are toxic and can secrete poison from their bodies as protection against predators or infraspecific competition. Neoteny has been observed in several species in Ambystomatidae, and some of them like the axolotl live all of their lives under water in their larval stage.
The Pacific giant salamanders are members of the genus Dicamptodon. They are large salamanders endemic to the Pacific Northwest in North America. They are included in the family Ambystomatidae, or alternatively, in their own monogeneric family Dicamptodontidae.
The California tiger salamander is a vulnerable amphibian native to California. It is a mole salamander. Previously considered to be a subspecies of the tiger salamander, the California tiger salamander was recently designated a separate species again. The California tiger salamander distinct population segment (DPS) in Sonoma County and the Santa Barbara County DPS are listed as federally endangered, while the Central California DPS is listed as federally threatened. The Sonoma County, south San Joaquin, and the Santa Barbara County DPS have diverged from the rest of the California tiger salamander populations for over one million years, since the Pleistocene and they may warrant status as separate species.
The long-toed salamander is a mole salamander in the family Ambystomatidae. This species, typically 4.1–8.9 cm (1.6–3.5 in) long when mature, is characterized by its mottled black, brown, and yellow pigmentation, and its long outer fourth toe on the hind limbs. Analysis of fossil records, genetics, and biogeography suggest A. macrodactylum and A. laterale are descended from a common ancestor that gained access to the western Cordillera with the loss of the mid-continental seaway toward the Paleocene.
The Santa Cruz long-toed salamander is an endangered subspecies of the long-toed salamander, which is found only close to a few isolated ponds in Santa Cruz and Monterey Counties in California. It has a black body, broken yellow or orange irregular striping along its spine, and a tail fin well evolved for swimming. Like other mole salamanders, it is found near pools or slow-moving streams and has a very secretive lifestyle, making it difficult to find.
The blunt-headed salamander is a mole salamander endemic to Mexico. It is only known from the vicinity of its type locality, near Morelia, in Michoacán state in Southwestern Mexico. It inhabits a landscape consisting of a mosaic of natural grasslands and pine-oak forests at elevations of about 2,000 m (6,600 ft) asl. Breeding takes place in ponds. An average adult has a mass of 6.18 grams while wet. Adult females of the species range from 42-93 mm and males range from 45.4-70.5 mm in standard length.
The Puerto Hondo stream salamander or Michoacan stream salamander is a mole salamander from the Trans-Mexican Volcanic Belt within the Mexican state of Michoacán.
The Tarahumara salamander is a freshwater species of mole salamander in the family Ambystomatidae, endemic to Mexico. Its natural habitats are temperate forest, subtropical or tropical moist montane forest, subtropical or tropical high-altitude grassland, rivers, freshwater marshes, pastureland, and ponds.
The Idaho giant salamander is a species of salamander. There are three closely related species to this taxon: D. ensatus,, D. copei and D. tenebrosus also known as the.
Cope's giant salamander is a species of salamander in the family Dicamptodontidae, the Pacific giant salamanders. It is native to Washington and Oregon in the Pacific Northwest region of the United States.
The coastal giant salamander is a species of salamander in the family Dicamptodontidae. It is endemic to the Pacific Northwest of North America. There are three closely related species to this taxon: D. ensatus, D. copei, and D. aterrimus.
There are 14 species of amphibians and 5 species of reptiles known to occur in Mount Rainier National Park.
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