Physical Description

  • Crab with large, rounded, smooth shell with triangular, sharp rostrum at front of shell.
  • Long, spindly legs and large front claws.
  • They often camouflage themselves by attaching bits of algae, sponges, bryozoans, or small animals to their long legs.
  • Coloration ranges from dark reddish-brown to dark purple to yellow-orange.
  • Males can reach 3.6 inches and females can reach 1.8 inches in shell diameter.


  • Santa Barbara, California to Magdalena Bay, Baja California, Mexico.


  • Found in rocky intertidal habitats, among the algae.
  • Found offshore in kelp beds.
  • Sometimes live in the surfgrass.
  • Live at depths of up to 300 feet.


  • A pre-courtship ritual is common, through smell and tactile cues.
  • Females can produce eggs every 30 days.
  • Females can hold as many as 61,000 developing eggs at once.


  • Mainly algae, especially brown algae.
  • Giant kelp and feather boa kelp.


  • Giant sea star, Kellet’s whelk.

Interesting Facts

  • They are also called the globose kelp crab.
  • They often molt their shells to rid themselves of unwanted shell adornments like barnacles or moss.
  • The algae, sponges, and bryozoans, they attach as camouflage can also act as defense mechanisms because they can taste and smell bad to predators.

Sources:; Cabrillo National Monument; Ambrose 1986; SeaLifeBase

Photo: Rocio Gajon Bunker