Cascade torrent salamander (Rhyacotriton cascadae)

Physical description

This is a small salamander that rarely exceeds 2.25 inches in length from snout to vent. The body is relatively long with short limbs and a short tail. The head is small with a short, rounded snout. Coloration is brown above and yellow to orange-yellow below. White speckling on the body appears mainly on the sides. Dark spots occur on the back and some on the belly. Varying amounts of dark dorsal spotting or mottling are a prominent feature of the color pattern, and a few black spots are often present on the belly. 

Cascade torrent salamanders have large prominent eyes. The large size of the eyes (eye diameter approximately equal to snout length), relatively short rounded snout and generally prominent yellow component to the belly color are features that help distinguish torrent salamanders from other Washington salamanders.

Adult male torrent salamanders can be distinguished from all other salamanders by the presence of prominent squared vent lobes, a trait unique to the family and the genus.

The color pattern and morphology of torrent salamander species are similar and variable; therefore, torrent salamander species are best identified by collection locality and how that relates to the documented ranges of each species.

Superficially, metamorphosed torrent salamanders resemble woodland salamanders (Plethodon species) and ensatina, but torrent salamanders lack nasolabial grooves and a constriction at the base of the tail (unique to ensatina). Torrent salamanders and rough-skinned newts have a similar color pattern, but differ in overall appearance with newts being stockier, having a thicker skin that is often rough (in the terrestrial phase) and lacking costal grooves.

Adult torrent salamanders have very reduced lungs and breathe mostly through their skin.

Larvae 

Torrent salamander larvae have well-developed functional limbs, prominent dorsally positioned eyes that do not greatly protrude, and a white (young larvae) to yellow-orange belly. Torrent salamander larvae are the only stream-adapted larval salamanders in Washington with a yellow to orange belly; stream-adapted salamanders have small gills and reduced tail fin.

Eggs

Eggs have not been found in the wild, suggesting females hide them well, perhaps in fractured rock or deep in springs. As in other members of the genus, eggs are thought to be unpigmented, laid singly and not attached to the substrate.

For more details about Cascade torrent salamander, see the Washington Herp Atlas.

Ecology and life history

This species is generally found in high-gradient, cold streams, seepages and waterfall splash zones, typically in areas with a thick canopy cover. Interestingly however, this species survived in many sites that were completely deforested by the 1980 eruption of Mount St. Helens. They usually occur in stream segments or off-channel habitats, such as seeps and waterfall splash zones, that are shallow, slow flowing and that have gravel or rock rubble that is silt-free. Adults are strongly associated with water and individuals are almost always found in contact with either free water or saturated substrates. During rainy wet periods individuals may be found in wet terrestrial forest settings away from streams or seepages.

Cascade torrent salamanders may be active year-round at lower elevations.

Breeding phenology is unknown, but may occur during most of the warmer months of the year. Eggs are most likely laid in the spring. The first described Cascade torrent salamander nest was found on 14 August 2003 in a second-order headwater stream on the west slope of the Cascade Mountains in Skamania County under a cobble-sized rock in the middle of a calm stretch of the stream channel 4 inches deep by 24 inches wide by 28 inches long. This differs from other Rhyacotriton species that are described as laying eggs in deep cracks and crevices of springs and seeps. The nest contained five eggs that were not attached to the substrate or each other.

The larval period is thought to be long; a Columbia Gorge population was estimated to require four to five years before metamorphosis.

Geographic range

In Washington, this species ranges from the west slopes of the Cascade Mountains south of Nisqually River to the Columbia River. Distribution is patchy. They can reach high densities in optimal habitat.

This map from the Washington Herp Atlas illustrates the distribution of Cascade torrent salamander in Washington based on records in the WDFW database as of 2016. If you see this species in areas that are not indicated on the map or have more recent observations (less than 10 years), please share your observation using the WDFW wildlife reporting form. 

Image

For maps of range-wide distribution and conservation status of this species, check out NatureServe Explorer and the International Union for Conservation of Nature Red List.