King crab

Presentation

The king crab is a large marine crustacean native to the cold waters of the North Pacific, recognizable by its spiny shell and long legs spread in a fan-like pattern. It actually belongs to the anomuran group, closely related to hermit crabs, although its body shape resembles that of true crabs. The species has been exploited commercially since the mid-twentieth century, particularly in the Bering and Okhotsk seas. It was deliberately introduced to the Barents Sea in the 1960s, where it has since become widely established. Its meat is highly prized in international cuisine, making it a major fishing resource. This crab lives on the sea floor at varying depths depending on the season.

The king crab has a triangular shell covered with spines and three pairs of visible walking legs, the fourth pair being reduced and hidden beneath the shell. Its color ranges from reddish-brown to orange, intensifying when cooked. The leg span can exceed one meter in the largest adult individuals.

Characteristics

Indicative values: they vary by subspecies, sex and region.

Habitat and distribution

The king crab inhabits sandy, rocky, or muddy seafloors, from the littoral zone down to several hundred meters deep. Juveniles prefer shallow waters while adults migrate to greater depths outside the breeding season. It tolerates a wide range of temperatures, which facilitates its geographic expansion.

Behaviour

This species is rather solitary outside breeding periods, during which it forms large aggregations on shallow coastal sea floors. It undertakes seasonal migrations between deep waters and shallow coastal zones. The king crab is primarily active at night and moves slowly across the marine substrate.

Reproduction

The female carries her fertilized eggs under her abdomen for approximately one year before hatching. Egg-laying occurs in winter, usually in shallow coastal zones. Planktonic larvae pass through several stages before metamorphosing into benthic juveniles.

Peculiarities

The king crab is not a true crab taxonomically but an anomuran, related to hermit crabs. Its introduction to the Barents Sea illustrates a notable case of an invasive species resulting from deliberate introduction, permanently altering local benthic ecosystems. Its impressive size and commercial value make it an emblematic species in Arctic fisheries.

Threats and conservation

In its native range, the species faces intense fishing pressure regulated by quotas. As an invasive species in the North Atlantic, it disrupts local ecosystems by competing with native species and altering benthic communities. Climate change could influence its future distribution.

References

Profile updated 28 August 2026 · Reviewed by the TunisieVet editorial team.

CONSERVATION STATUS

Data deficient (DD)

IUCN source, latest published assessment.

Documented diseases for this species.

This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.

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