Hairy Hermit Crab (Pagurus hirsutiusculus)

Description: Hairy hermit crabs are one of multiple hermit crab species found in the tide pools of Haystack Rock. To avoid mistaking it for other hermit crabs, look for these 3 key features: (1) many little hairs covering its body, (2) white bands circling around the second and third pairs of walking legs, and (3) little bands around their antennae. Its entire body is usually a dark green or brown color. They average about 2 centimeters in length but can sometimes be 3 centimeters long, which makes them a pretty tiny critter!

Habitat: Hairy hermit crabs like to live in the protected waters of tide pools, typically hiding underneath rocks or algae. These creatures are easily startled; the slightest of movements will have them curling their legs up inside their shell to hide from predators. Aside from being found at Haystack Rock, hairy hermit crabs range geographically from central Alaska to central California. 

Diet: Hermit crabs are scavengers, meaning they go around tide pools searching for decomposing algae or dead animals to eat. They’re able to sense these sorts of things with their very long antennae.

Tide Pool Tidbits:

• While the primary defense mechanism of other hermit crabs is to hide in their shell, the hairy hermit crab will completely abandon its shell to escape predators. Hairy hermit crabs are able to dart around very quickly, so sometimes it’s best to drop the extra weight from their shell to get out of harm’s way. 

• Hermit crabs don’t grow their shells; instead, they find abandoned shells left behind after snails die to move into. As hermit crabs grow, they continuously need to find bigger and bigger shells to live in.

• The appropriate way to pick up a hermit crab is to reach out slowly to avoid startling it, then pick it up by its shell from behind to avoid getting pinched. Then, to hold it, place out a flat palm (having your fingers pressed flat together makes it harder for them to pinch you). It’s best to hold a hermit crab only slightly above the water in case they fall out of your hands so that they don’t drop from super high up. Always make sure to put any tide pool creature back in the exact spot you found it in, because that’s its home!

• Sometimes, it’s possible to find a hairy hermit crab with barnacles either growing on its shell or on its legs.

Reference: Central Coast Biodiversity