Pagurus hirsutiusculus are darkly colored crabs, olive green or black with green-brown legs (3). The carapace and legs are covered with setae, small hair-like projections (3). While the antennae and legs have similar coloration with the carapace, they do have several distinctive white bands (1). Rarely larger than 4 cm long these hermit crabs occupy uninhabited shells from gastropod, preferring angular unicorn shells (1). Size and shell preference vary with geographic location, with P. hirsutiusculus found in southern California tending to be smaller and choosing shells that more closely correlated with their size compared to P. hirsutiusculus found in Alaska (2).
(1) Allen, R. K. (1990). Common intertidal invertebrates of southern California. Needham Heights, MA: Ginn Press.
(2) Blackstone, N. W. (1989). Size, shell-living and carcinization in geographic populations of a hermit crab,Pagurus hirsutiusculus. Journal of Zoology, 217(3), 477-490. doi:10.1111/j.1469-7998.1989.tb02503.x
(3) Cowles, D. (n.d.). Pagurus hirsutiusculus (Dana, 1851). https://inverts.wallawalla.edu/Arthropoda/Crustacea/Malacostraca/Eumalac...
- rocky intertidal