Evolution and systematics
Torrent salamanders represent a novel lineage of salamanders that don't have any shut family. Morphological and molecular information attest to the distinctiveness of this clade, however there isn't a clear sister taxon. These salamanders could also be remnants of an early radiation of the Salamandroidea. When first found early within the twentieth century, these salamanders have been thought family members Hynobiidae (effectively represented in japanese Asia however not in any other case recognized within the New World). They then have been included within the Ambystomatidae and later within the Dicamptodontidae. In a number of respects, they resemble plethodontids, they usually could also be associated to that group. At current torrent salamanders are acknowledged as a separate household.
These are small to medium-sized (3–4.5 in; 7.5–11.5 cm) semiaquatic salamanders with comparatively stocky our bodies and broad heads with protuberant eyes and a brief snout. Limbs are small however strong, and the tail is brief and laterally compressed with a small keel. These salamanders have vestigial lungs.
This household happens from the Olympic Peninsula in northwestern Washington within the coast ranges to southern Mendocino County in northern California, and within the Cascade vary from the neighborhood of Mount Saint Helens, Washington, to Lane County, central Oregon.
Torrent salamanders are aquatic and semiaquatic, inhabiting normally densely forested areas in small, clear, quickly flowing streams, seeps in rocky areas, and rock crevices with skinny layers of water cascading over the floor.
The habits of this household just isn't well-known. These salamanders are secretive and are seldom seen.
Feeding ecology and weight loss plan
Little is understood in regards to the feeding ecology of this household. The weight loss plan in all probability consists of aquatic and semiaquatic bugs, particularly larvae, in addition to different invertebrates.
Fertilization is inner. Large, unpigmented, yolky eggs are laid in chilly, clear water underneath rocks or in crevices. Eggs develop slowly, as do the aquatic larvae, which stay for 3 or 4 years. Metamorphosis happens at shut to grownup measurement, however it's not recognized how lengthy it takes metamorphs to mature. Metamorphosis is a gradual and delicate transformation. Adults are characterised by morphology extra typical of juveniles of different taxa, particularly with respect to skulls and limbs.
No species are listed by the IUCN. Clearing of forests is the best threat to torrent salamanders, as a result of it leads to habitat degradation. One species, Rhyacotriton variegatus, is protected in California.
Significance to people
The 4 species of this household are in all probability comparable to one another in ecology and different organic options. They kind a novel clade that harbors distinctive parasites. The main significance to people is a contribution to understanding of the scale of biodiversity within the Pacific Northwest area of California.