Invertebrates
Red King Crab
Paralithodes camtschaticus · also called Alaskan king crab
Spanning nearly two metres across its outstretched legs, a red king crab looks every bit like one of the ocean’s largest true crabs, yet its closest relatives are actually the far smaller hermit crabs sharing the same cold North Pacific waters.
Overview
The red king crab, Paralithodes camtschaticus, is a large, commercially important crustacean native to cold ocean habitat across the North Pacific, including waters off Alaska and the Russian Far East. Its enormous leg span, true kinship with hermit crabs rather than genuine crabs, and status as the target of one of the world’s most demanding fisheries make it one of the most economically significant crustaceans found anywhere in the ocean.
A giant with an unexpected family tree
Despite its imposing size and crab-like shell, genetics place the red king crab firmly closer to hermit crabs than to true crabs, one of several examples across the animal kingdom where a familiar body plan evolved independently in an unexpected lineage.
Status
Least Concern, though populations have fluctuated significantly in parts of the North Pacific due to commercial fishing pressure and environmental changes.
Red King Crab: common questions
Is the red king crab a true crab?
Not closely, this species belongs to the group Anomura rather than the true crabs, making it more closely related to hermit crabs than to genuine crab species, despite its common name and crab-like appearance.
How big can a red king crab get?
This species can span nearly two metres across its outstretched legs, ranking among the largest crab-like crustaceans in the world by overall leg span.
Why does the red king crab fishery have a dangerous reputation?
The commercial fishery targeting this species has historically been considered one of the most dangerous fishing occupations, conducted in the harsh, cold, and often stormy waters of the North Pacific where the species is found.
How many pairs of legs does a red king crab have?
This species has only three pairs of visible walking legs rather than the four pairs typical of true crabs, with a smaller fourth pair reduced and tucked out of sight beneath its shell.