Comprehensive DescriptionRead full entry
Plethodon elongatus is a medium-sized terrestrial salamander. Compared to other species of Plethodon in the Pacific Northwest they are long and slender, with a modal number of 18 costal grooves (Brodie and Storm 1971; Petranka 1998). Adults are 6 - 7.5 cm snout to vent length (11 - 15 cm total length) (Stebbins 1985; Petranka 1998). The limbs are relatively short and the toes are short and slightly webbed (Brodie and Storm 1971; Stebbins 1985). Dorsal coloration is dark brown or black, with a reddish or reddish-brown straight-edged mid-dorsal stripe. The stripe may extend from head to tip of tail, but may be less pronounced in older animals. The venter is dark gray, with throat light gray and mottled (Petranka 1998). White or yellow flecks are concentrated on the sides, dorsal surface of the limbs, and gular (throat) region. These flecks are sparser on the head and venter, and rarely on the dorsal surface (Brodie and Storm 1971). Males are slightly larger than females and have a mental gland, a raised region on the chin used in courtship (Petranka 1998). With age, the jaw closing muscles become more pronounced and the region behind the eyes has a distinct bulge (D. B. Wake, pers. comm.). Hatchlings are about 18 mm snout to vent length and they have a more distinct dorsal stripe than adults (Brodie and Storm 1971; Petranka 1998).
Some authors recognize the Siskiyou Mountains salamander, P. stormi, as a subspecies of the Del Norte salamander (e.g. Stebbins 1985). Currently these are recognized as two separate species (e.g. Petranka 1998), but a detailed examination of geographic variation in morphology and genetics for both species is necessary to resolve this issue.
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