This salamander is the largest terrestrial salamander in the Pacific Northwest and one of the largest terrestrial salamanders in the world (Petranka 1998). Body stout and powerful. Smooth skin. Dorsal ground color is dark brown or gray to black with well defined irregular marbling of purple to reddish brown. Degree of marbling varies among individuals and among populations. Underside is usually light colored: lightish brown to off-white. The posterior half of the tail is laterally compressed, and the head is depressed in front of the eyes.
Larvae generally measure from 33 mm TL up to 30 cm which is the size of some untransformed adults (Petranka 1998). They have tail fins that extend forward to the insertion of the hindlimb. The gills are bushy and purplish to red. Ground color of larvae is light to dark brown. The larvae frequently have a yellow stripe behind the eye, and the toe tips are covered with dark, cornified skin (Nussbaum 1976) . Some older larvae are mottled.
Dicamptodon tenebrosus has until recently been included in D. ensatus, but recent genetic research has shown that the coastal Giant Salamander consists of two distinct species, D. tenebrosus to the north and D. ensatus to the south (Good 1989). These two species interbreed over a 4.7 km contact zone near Anchor Bay in Mendocino Co., CA, but there is very little gene flow (Good 1989). There is a hybrid deficiency and there is little evidence of introgression outside the narrow hybrid zone (Petranka 1998).
This species is remarkable in their gregariousness, their formidable bite, their production of a "bark" (Stebbins 1951 1985), their large size, and their consumption of mammals and other amphibians.
More work is necessary to determine the impacts that logging has had and the impacts that future logging could have on the abundance of this species.
See another account at californiaherps.com.