Southern torrent salamander | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Family: | Rhyacotritonidae |
Genus: | Rhyacotriton |
Species: | R. variegatus |
Binomial name | |
Rhyacotriton variegatus Stebbins & Lowe, 1951 | |
The southern torrent salamander (Rhyacotriton variegatus) is a member of the salamander family Rhyacotritonidae. This species of torrent salamander is found the farthest south in the region. It is a small salamander endemic to the Pacific Northwest from Northern California to Northern Oregon. It is one of four species of Rhyacotriton, along with R. cascadae , R. kezeri and R. olympicus . All species of Rhyacotriton are small, with their body lengths being less than 5 inches. The species reproduces annually, with an extended courtship and egg-laying period. [2] The time it takes from oviposition to reach sexual maturity ranges from five to eight years, making the generation interval rather long. [2] The larval stage, from hatching to metamorphosis, lasts 2.0-2.5 yr, with females requiring another 1.5–2.0 yr until they can first breed. [2] They reach sexual maturity 1.0-1.5 yr after metamorphosis which occurs between 4.5 and 5.0 yr. This species feeds on small insects and spiders. Although it is found over a large area, it is not a migratory creature. It is preyed on by Pacific giant salamanders and garter snakes.
The species in the genus Rhyacotriton are all similar in morphology, but have high genetic diversity. R. variegatus lives in aquatic environments from egg through metamorphic stages. Through adulthood individuals live on the waters edge among pebbles and rocks. R. variegatus has the lowest desiccation tolerance of all North American salamanders, meaning they cannot easily withstand “extreme” temperatures and low moisture levels. [3] The habitats preferred by R. variegatus are cool, shallow, high in oxygen, and slow-flowing, such as seeps and mountain brooks, with coarse, gravel-like beds. These water sources are found mostly in forests, which is where R. variegatus is most often found. [3] All species of Rhyacotriton have aquatic eggs and larvae, and adults are semi-aquatic. R. variegatus adults can venture away from the stream, but they prefer the water, only coming out when the moisture level of the ground is high enough. [3] Adults and juveniles are subject to moisture loss as well as heat shock. [4]
The southern torrent salamanders are small salamanders; mature adults measure from 1.5–2.4 inches snout to vent. On their dorsal sides, they are brown with darker spots. Their ventral sides are more yellow, with the same spots as the dorsal sides. The colors vary by shades; the dorsal sides range from dark olive to a dark brown. Their eyes face forwards and are large and dark, and metallic flecks surround the eyes. Males are distinguished from the females by their square cloacal lobes. Lungs of the adults are also reduced in appearance. Their bodies are slender, with long tails about the same length as their torsos. They have four legs, set in pairs – two close to the head, and two near the base of the tail. At the base of the leg, they have four toes used to grip and climb. Generally, they have blunt noses and protruding eyes.
The genus Rhyacotriton is found in the Pacific Northwest, extending from Northern California to the Olympic Peninsula. R. variegatus is endemic to the southernmost part of the range, extending from California to Oregon. Populations of R. variegatus are found in forests of the coastal regions of the states. Some Rhyacotriton species are found more inland, but they are still relatively close to the coast; these are mainly populations of R. kezeri. The areas with populations of R. variegatus are forests with fresh water sources that meet all of their habitat requirements. Although most of the population is in one continuous range, a smaller population separated from the main range is found in southwest Oregon. Though it is disconnected from the range, it is still close to the coastline.
R. variegatus occurs in coastal coniferous forests in California and Oregon. Older forests are more likely to maintain a population of southern torrent salamanders. These forests have >80% canopy coverage due to sizeable trees, as well as large amounts of moss. [1] Some younger forests have the proper habitat to keep a population, but it is unusual to see a population living in a young forest. Reproduction occurs in the water, where the fertilized eggs are laid and abandoned. [2] Mating occurs after an extended courtship, and is followed by a long egg-laying process. The eggs take quite some time to hatch, and the whole larval stage lasts about 2.0-2.5 yr. [2] Usually, the female lays one egg at a time, but occasionally clutches of eight to 11 eggs are found. [5]
Efforts have been made to conserve this species. After being assessed, it was placed in the “Least Concern” category, meaning there is no immediate threat to the survival of the species, and it has a wide distribution with an assumed large population. [1] Though there is no immediate threat to the southern torrent salamander, urbanization is beginning to encroach on its habitat. Direct effects from logging and disturbing forests with the building of roads and other man-made features are limiting the habitable areas for these salamanders. [1] Other indirect effects from urbanization are those that are affecting the temperature of the environment. R. variegatus is extremely sensitive to temperature fluctuations, having a very narrow range of temperatures in which it can thrive. [3] The salamanders will begin to show temperature stress at about 63 °F. If the temperature of mountain streams and brooks rises over the next few years, the species will either have to adapt or succumb to the warm temperature. In California, R. variegatus is a Species of Special Concern. [2] The composition of the ground in the habitat is also quite important. If the texture of the components is too fine, then the environment would not be ideal. R. variegatus needs large, pebble-like particles to be able to hide and avoid predators. Many concerned people still petition to place R. variegatus in a more at-risk category because of the previously unregulated logging that altered the population. [1] The species will remain at least concern status until the populations become more threatened.
The torrent salamanders or Cascade salamanders are a family of salamanders (Rhyacotritonidae) with only one genus, Rhyacotriton. The torrent salamanders are endemic to the United States in the Pacific Northwest.
The northwestern salamander is a species of mole salamander that inhabits the northwest Pacific coast of North America. These fairly large salamanders grow to 8.7 in (220 mm) in length. It is found from southeastern Alaska on May Island, through Washington and Oregon south to the mouth of the Gualala River, Sonoma County, California. It occurs from sea level to the timberline, but not east of the Cascade Divide. Its range includes Vancouver Island in British Columbia and The San Juan Islands, Cypress, Whidbey, Bainbridge, and Vashon Islands in Washington.
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 western toad is a large toad species, between 5.6 and 13 cm long, native to western North America. A. boreas is frequently encountered during the wet season on roads, or near water at other times. It can jump a considerable distance for a toad. Breeding occurs between March and July in mountainous areas, and as early as January in lower-elevation regions. The female lays up to 17,000 eggs stuck together in strings that adhere to vegetation and other objects along water edges.
The barred tiger salamander or western tiger salamander is a species of mole salamander that lives in lower western Canada, the western United States and northern Mexico.
Van Dyke's salamander is a small woodland salamander in the family Plethodontidae, the lungless salamanders. These animals breathe through their skin and are largely terrestrial. Compared to other salamanders in Plethodon it is relatively stocky with long legs. Usually associated with streams, seepages, and rock outcrops, it is endemic to Washington where it is found in a limited number of small, isolated populations.
The Cheat Mountain salamander is a species of small woodland salamander found only on Cheat Mountain, and a few nearby mountains, in the eastern highlands of West Virginia. It and the West Virginia spring salamander are the only vertebrate species with geographic ranges restricted to that state.
The gregarious slender salamander is a species of salamander in the family Plethodontidae. Its natural habitats are California interior chaparral and woodlands and temperate grasslands in the lower foothills of the western Sierra Nevada and the eastern Central Valley in California, United States.
The seepage salamander is a small, terrestrial species of salamander in the family Plethodontidae. It is endemic to the United States. They are found in small areas of Tennessee, North Carolina, Georgia, and Alabama. Its natural habitats are temperate forests, intermittent rivers, and freshwater springs. It gets its name from the seepages around which it lives. It is very similar in its appearance and life history to the pygmy salamander. These two species differ greatly from the other Desmognathus species. They are the smallest salamanders in the genus, measuring only 3–5 cm (1–2 in) in length. They are also the only two terrestrial, direct-developing Desmognathus species. However, the two species are not often seen to coexist, differing in distribution by elevation; although there are exceptions. The seepage salamander is currently listed as Near Threatened, with its numbers declining in most of states in which it is found. It is threatened by habitat loss, with logging having a major effect.
Desmognathus fuscus is a species of amphibian in the family Plethodontidae. The species is commonly called the dusky salamander or northern dusky salamander to distinguish it from populations in the southern United States which form several distinct species, the southern dusky salamanders. The northern dusky salamander is the most widespread representative of its genus in Canada. It can be found in eastern North America from extreme eastern Canada in New Brunswick south to South Carolina. The size of the species' total population is unknown, but is assumed to easily exceed 100,000. The species' habitat differs somewhat geographically; dusky salamanders in the northern part of the range prefer rocky woodland streams, seepages, and springs, while those in the south favor floodplains, sloughs, and muddy places along upland streams. They are most common where water is running or trickling. They hide under various objects, such as leaves or rocks, either in or near water. Alternatively, they may enter burrows for protection. The dusky salamander lays its eggs close to water under moss or rocks, in logs, or in stream-bank cavities. The larval stage which follows is normally aquatic.
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The Cascade torrent salamander is a species of salamander in the family Rhyacotritonidae. It is endemic to the Pacific Northwest in the United States where it is found from Skamania County in Washington south to Lane County in Oregon on the west slope of the Cascade Mountains.
The Columbia torrent salamander is a species of salamander in the family Rhyacotritonidae, endemic to the Pacific Northwest in the United States. It is found in the coastal areas of Washington to northwestern Oregon.
The Olympic torrent salamander is a species of salamander in the family Rhyacotritonidae. This is a small salamander that lives in clear, cold, mountain streams. It is medium to dark brown and may have a few small light spots on the sides and small dark spots on the tail; it is bright yellow on the belly, usually with some dark spots. Torrent salamanders typically have short snouts and relatively large eyes. As in other torrent salamanders, adult males have square-edged lobes behind the cloaca. These salamanders live at the edges of clear, cold, mountain streams; they can be abundant under gravel at stream edges and in the spray zones of waterfalls. During rainy seasons, they are occasionally found under objects on land away from streams.
There are 14 species of amphibians and 5 species of reptiles known to occur in Mount Rainier National Park.
Media related to Rhyacotriton variegatus at Wikimedia Commons Data related to Rhyacotriton variegatus at Wikispecies