Hairy Hermit Crab      Pagurus hirsutiusculus



Hermit crabs are a common site when exploring the intertidal zone of a rocky or sandy mud beach.  Unlike most crabs that have a full suit of armor to protect them from predators, hermit crabs have adopted another strategy.  They protect their soft abdomen with the shell of a snail.  As they grow they must spend lots of time looking for a bigger house to live in.  When they come upon an empty shell they will explore the inside of the shell to see if it will fit them and is of good quality.  If it works they will slip out of the old and into the new, quick as a wink. Their soft abdomen is curved to fit in a snail shell and one of their last pair of legs are modified into hooks to hold the crab in the shell.


Of the several species of hermit crabs in our area, the hairy hermit is unique with it's multiple fine body projections which look like hairs.  This specimen has collected fine mud particles on the hairs which probably serve to camouflage it on a mud sand beach.  Another distinguishing feature of this species is the banded antennae.


This species along with several other species occur along the west coast from Alaska to Mexico.  They range from the mid intertidal zone to the shallow subtidal zone, where they feed on fine organic particles in the mud or other scraps that come their way.


Like other crabs, the females incubate the eggs by holding them on the abdomen with modified legs.  After hatching larvae stay in the plankton for a number of days till they mature and settle to the bottom.