There are three species of Tanner crab in British Columbia. Chionoecetes bairdi is the nearshore, relatively shallow water species, native to the Pacific coast of North America from Alaska to Oregon and is not generally found in the eastern Pacific, although there are reports of them occurring off Japan. Their major abundance in British Columbia appears to be the northern mainland inlets where they were fished commercially until 1993. There currently is no commercial fishery and recreational harvesters rarely encounter them because of their depth.

The other two species, Chionoecetes tanneri and Chionoecetes angulatus, are deepwater spider crabs (500 to 3000 metres) and are found along the continental slope from California, around the Aleutian chain, to Japan. Attempts to develop a commercial fishery for these two species in British Columbia have been unsuccessful.

Tanner crabs are large, spider crabs with four pairs of slender, pointed walking legs and a pair of claws about the same size as their legs with two narrow, curved pincers. Their carapace (shell) is round and flattened, with two 'horns' on the front.

Chionoecetes bairdi - the shallowest of the three species - is brown in colour and has a rough, bumpy surface. Their undersides are pinkish orange to cream. These nearshore Tanner crabs grow to a maximum carapace width of about 140 millimetres in British Columbia, with males considerably larger than females. It is believed that they live up to 14 years.

The deepwater species, Chionoecetes tanneri (grooved Tanner crab) and Chionoecetes angulatus (angle Tanner crab) have bright orange shells with enlarged lobes over the gill region.