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

Discorsopagurus schmitti (Stevens, 1925)
Tubeworm Hermit Crab
Family: Paguridae

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

© Aaron Baldwin  Email the photographer   (Photo ID #2101)

E-Fauna BC Static Map
Distribution of Discorsopagurus schmitti in British Columbia
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Species Information

Carapace: shield slightly longer than wide. Eyestalk relatively long and stout; cornea a little dilated. Right cheliped setose and slightly longer than walking legs, with spines and granules scattered over surface, especially on carpus and hand; with inner margin of palm serrate with large, sharp teeth and outer margin with a row of spines. Left cheliped more slender but nearly as long as right; carpus and hand with spines and sharp granules. Walking legs slender and setose; dactyl shorter than propodus; claw curved and stout. Abdomen straight; uropods symmetrical; pleopods only on left side. Calcified plates indicate segmentation of abdomen.


Shield length: male 4.5 mm.


Carapace: shield light brown and posterior brown with mottling of purplish red and grey. Chelipeds yellow with red-brown dappling; fingers dark brown laterally and scarlet and white dorsally. Walking legs: ischium red-brown; merus yellowish with proximal and distal bands of dappled red-brown, carpus yellow with red-brown dappling dorsally; propodus yellowish with narrow red-brown band proximally; dactyl with bands of red-brown, yellow and scarlet; claw yellow. Eyestalk greenish-brown proximally and blue-grey with red stripes distally; cornea black with some gold flecks. Antennal flagellum orange or scarlet and somewhat translucent.


Usually occupies empty, encrusted, leathery tubes of the worm Sabellaria cementatium, in deep water, or empty calcareous tubes of Serpula vermicularis, in shallow water. Because these tubes are encrusting forms, the crabs are mostly sessile, but quite mobile when inhabiting a loose portion of tube.



Northwestern Pacific; Hayward Strait, Sitka Sound, Alaska (57°20’15”N, 135°50’30”W), to Puget Sound, Washington; intertidal to 220 m.
Distribution In British Columbia

Widespread but easily missed.

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

The tubeworm hermit crab is considered an 'unconventional' crab because it uses as a shelt only the fixed tubes produced by the worm Sabellaria cementarium Moore (Gherardi 1996). Tubes are strongly defended from invaders, but are more fragile than shells and more easily eaten by predators (Gherardi 1996).

Additional Photo Sources

Species References

Gherardi, Francesca. 1996. Non-conventional hermit crabs: Pros and cons of a sessile, tube-dwelling life in Discorsopagurus schmitti (Stevens). Journal of Experimental Marine Biology and Ecology 202 (2): 119-136.

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: 2023-11-30 9:58:12 AM]
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