E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Oedignathus inermis (Stimpson, 1860)
Paxillose Crab
Family: Lithodidae

Species account author: Josephine Hart.
Extracted from Crabs and their relatives of British Columbia.
Photo of species

© Aaron Baldwin  Email the photographer   (Photo ID #4305)

E-Fauna BC Static Map
Distribution of Oedignathus inermis in British Columbia
Details about map content are available here.

Species Information

Carapace somewhat pear-shaped, with short triangular rostrum, and covered with blunt spines and soft setae. Eyestalk short and cone-shaped; cornea small. Chelipeds unequal in size, the larger covered with flat, wart-like masses of granules; fingers spoon-like. Smaller cheliped and walking legs setose with minute sharp granules. Walking legs subcylindrical with short stout dactyls, strong movable spines ventrally, and a strong curved claw. Abdomen soft with basal and terminal segments strengthened by flat calcareous plates.


Carapace: male 30 x 25 mm, female 22 x 20 mm.


Carapace grey-brown and white, with orange granules surrounding white, and with dark red setae and gold bristles. Colour often masked by mud. Large cheliped with ischium and merus blue-grey or tan with red-brown areas; carpus tan with blue-violet or white granules and flat blue granules laterally. Hand brownish with granules violet-blue and pale blue to white laterally; fingers violet and violet-blue granules with smooth tips tan. Small cheliped with ischium and merus white or tan, and a maroon network with a turquoise stripe. Carpus and hand brown with white-tipped orange knobs, red and gold setae, and fingers darker brown with orange tips and dark brown setae. Walking legs white or tan with maroon streaks, green, red and white setae; granular knobs chocolate brown with white tips; dactyl maroon deep yellow with black spines and claw. Eyestalk brown and white, with cornea black but covered with red film. Base of antenna red and brown; acicle orange and flagellum tan.


Open coast in rocky crevices, abandoned sea urchin holes, under kelp holdfasts and between green anemones, such as Anthopleura xanthogrammica, and California mussels, Mytilus californianus.



Northwestern Pacific (Japan), Unalaska, Alaska, to Pacific Grove, California; intertidal to 15 m.
Distribution In British Columbia

Outer coasts of Queen Charlotte Islands and Vancouver Island. I have taken them as far east as China Beach on southern Vancouver Island, but the only record for the Strait of Georgia is apparently Porlier Pass where they were found from 5 - 15 m (Neil McDaniel pers. comm. 1978).

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Photo Sources

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-06-21 8:56:13 PM]
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