Comprehensive DescriptionRead full entry
A small to medium-sized, semi-aquatic salamander. Dorsal coloration is brown and the underside is bright yellow. Black flecks or spots occur on the back and more densely on the sides. The degree of black spotting or blotching varies with locality, but there seems to be no geographic pattern. The belly sometimes has small grayish flecks. Some populations have a dark stripe on the underside of the tail, posterior to the vent opening. Males have squared, glandular lobes on either side of the vent opening, a trait unique among salamanders (Sever 1988). These salamanders have a short, rounded snout and relatively large, prominent eyes. The tail is relatively short, less than the snout to vent length. Description from Good and Wake (1992),Leonard et al. (1993), and Petranka (1998). Adult body size is 4.0 to 5.1 cm snout to vent length (7.5 - 11 cm total length) (Good and Wake 1992; Petranka 1998). Females are slightly larger than males (Good and Wake 1992).Larvae are of the stream type, with very short gills and a low dorsal tail fin that does not extend onto the back. Coloration is similar to the adult pattern (Stebbins 1985; Leonard et al. 1993).Hatchling size is about 15.8 mm snout to vent length (Nussbaum and Tait 1977).
Until recently the genus Rhyacotriton contained a single species with two subspecies, R. o. olympicus and R. o. variegatus. Genetic studies revealed substantial variation and subdivision throughout the range and the single species was split into four species: R. olympicus, R. variegatus, R. cascadae, and R. kezeri (Good et al. 1987; Good and Wake 1992).