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

Cancer productus Randall, 1839
Red Rock Crab
Family: Cancridae

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

© Tim Loh  Email the photographer   (Photo ID #77972)

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


The red rock crab is a hunting species of crab that actively forages in the intertidal zone, often excavating to find its prey (Smith et al. 1999). Foraging occurs most often in shoreline areas protected from wave action (Robles et al. 1989). Males forage most often during the day, while females forage more commonly at night (Robles et al. 1989). Diet includes clams, barnacles, smaller crabs, amphipods, sea cucumbers, polychaetes, other intertidal invertebrates and dead fish (Cowles 2005). As with other species, males will guard females during the molt, protecting them until their exoskeleton hardens--mating occurs after the molt. (Cowles 2005). Predators include bass and sculpin (on juveniles) and seabirds--this species is reported to be a favourite prey item of the giant Pacific octopus (Cowles 2005, Wikipedia 2010). Recent research has shown that, while adults are fairly uniform in colour (primarily dark reddish with white spots), juveniles show a remarkable array of colours and shell patterns, which may reduce visibility to predators (Krause-Nehring et al.2010). There is no commercial fishery for this species in BC.

View a photo of the colour variation in juveniles of this species.

Species Information

Front with 5 subequal teeth. Carapace surface uneven and slightly convex; antero-lateral teeth shallow, rounded and become more acute posteriorly with only one obscure postero-lateral tooth. Chelipeds stout, rugose; fingers dark coloured. Walking legs with dactyls fringed with short stiff setae.


Carapace: male 103 x 180 mm, female 81 x 158 mm.


Carapace dark red with white or red granules on yellow spots on elevations; front dark brown with white or pink granules. Chelipeds white, tan, orange dark red and purple-red; fingers and teeth tan, tips blue grey or black. Ventrally, white with patches of orange and red with bluish granules. Eyestalk white with irregular red bands; cornea black with gold flecks. Juveniles with carapace varicoloured, often symmetrically striped in dark and light colours.


Rocky shores, hidden under rocks or partly buried under gravel or mud.



Kodiak, Alaska, to Laguna Beach, California; intertidal to 79 m.
Distribution In British Columbia

Widespread and common.

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 Notes

"Cancer productus is carnivorous and in Puget Sound will crush barnacles with its large chelipeds for consumption". (Wikipedia 2010).

Synonyms and Alternate Names

Cancer perlatus Herbst 1790
Platycarcinus productus Randall 1839

Additional Photo Sources

Species References


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: 2024-05-29 7:20:46 AM]
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