Click for more images

Coastal Giant Salamander

Dicamptodon tenebrosus

Family: Dicamptodontidae

COSEWIC status:
  • Threatened
SARA status:
  • Threatened
IUCN status:
  • Least Concern

Description

The Coastal Giant Salamander is one of the largest terrestrial salamanders in North America and can grow to over 30 cm in total length, although most individuals are smaller than this. It is heavy-bodied with 12–13 indistinct costal groves, a broad head and a laterally compressed tail. The back is dark brown to black, usually with a marble-like pattern of tan to gold that can fade with age. Terrestrial adults lose their gills when they mature, although neotenic adults (see biology) retain their gills. The larvae have broad heads, feathery gills behind the head, legs (both front and back) and an obvious tail fin.

Similar Species

No other large salamanders in the range of the Coastal Giant Salamander have a marbled pattern of brown to gold. The relatively large Northwestern Salamander has paratoid glands (bulbous areas on each side of the head) and is mostly dark in colour. The larvae of other BC salamanders are not large enough to be confused with a neotenic (see biology) Coastal Giant Salamander.

Distribution

Click for larger image

The Canadian range of the Coastal Giant Salamander is limited to a small area in the southwestern mainland of British Columbia. In the United States, the range extends along the western portions of Washington, Oregon and northern California.

Habitat

Coastal Giant Salamanders breed in clear, fast-flowing streams in mature and old growth forest. Terrestrial adults inhabit upland forest within close proximity to these streams. Logs, rocks and other cover objects provide important microhabitats for terrestrial adults. Neotenic individuals (adults that retain larval form) can be found in rivers, lakes, ponds and large streams.

Biology

Coastal Giant Salamanders breed throughout the active season, but females only breed every second year. Females lay 85–200 large (more than half a centimeter in diameter) eggs singly or in small clumps on the underside of rocks or logs within streams and they will stay with the eggs until they hatch in the fall. The larvae are aquatic and take five or six years to mature into adults. Larvae may develop into terrestrial adults or they may retain larval features as adults (neoteny), including gills, and remain aquatic. In BC, aquatic neotenic adults are found more commonly than terrestrial adults. Neotenic forms need permanent water bodies for survival. In smaller streams, larvae are more likely to develop into terrestrial adults, likely because smaller streams are prone to drying up. Terrestrial adults are opportunistic carnivores and forage in upland forest habitat during rainy periods for insects, snails, slugs, amphibians and even small mammals such as shrews. Aquatic individuals eat aquatic invertebrates, amphibian larvae and small fish. Individuals can live for more than 20 years.

Threats

Logging and the subsequent sedimentation of stream habitats is a significant threat to Coastal Giant Salamanders in BC. This species is especially sensitive to pollution and other activities that affect water quality. Other threats include habitat loss and fragmentation and road mortality, especially in areas with high human populations. Climate change and introduced pathogens pose potentially serious threats to Canadian salamanders.

Additional Information About This Species In Canada