How to Distinguish from Similar Species: Of the species common in the intertidal, no others have the blue dots all over the legs. P. beringanus has red bands and red dots on the legs. P. hirsutiusculus has no dots and hairy legs. P. hemphilli has dark red legs with yellow spots, with a white dot at the end. P. samuelis is found only on the open coast and has red antennae and a blue band on the dactyls of legs 2 and 3.
Geographical Range: Unalaska, Aleutian Islands, Alaska to Bahia de Todos Santos, Baja California. Less abundant than P. samuelis in California and south.
Depth Range: Low intertidal to 36 m
Habitat: Rocky, cobbles, and among algae.
Biology/Natural History: This species is often found in Tegula funebralis, Searlesia dira or Nucella lamellosa shells. Small individuals live in Littorina shells. It seems to prefer shells large enough that it can completely withdraw inside. It lives lower in the intertidal than does P. hirsutiusculus but higher than P. beringanus. This is said to be the smallest intertidal hermit crab to be found in Puget Sound, but I have not noticed it being particularly small. Predators include the black prickleback, Xiphister atropurpureus. The species is active mainly in the afternoon and night, and sometimes can be found in large aggregations on shallow sand bottoms. They produce 3 broods per year in the Puget Sound area. The females carry their eggs for about 55 days, and the planktonic zoea/megalops stages last about 70 days.
In Puget Sound this hermit is said to change shells more often than does P. hirsutiusculus, and holds onto its shells more tenaceously. It is often able to evict P. hirsutiusculus from its shell and take it over.
Flora and Fairbanks, 1966
Kozloff 1987, 1996
Smith and Carlton, 1975
General Notes and Observations: Locations, abundances, unusual behaviors:
I find this hermit crab on Sares Head much more often
Authors and Editors of Page:
Dave Cowles (2005): Created original page