Hermit Crab (Pagurus bernhardus)

Hermit crabs usually live in the shells of prosbranch molluscs. There are many species, Pagurus bernhardus, is one of the most common.

The hermit crabs vary although they have in common the asymmetrical body, with the abdomen curved to accommodate an empty mollusc shell. The antennae are long and the eyes are out on stalks.

These are important scavengers. They feed on dead organisms that become trapped in rockpools by the dropping tide. They scurry around and feed on the decaying matter. As hermit crabs grow they search for a bigger shell to fit into, grabbing hold of the inside of the shell with a modified uropod. After they find one they drop their current shell and try on the new one. Weight as well as size is important. They will withdrawl completely inside when disturbed.

Common in rock pools on middle and lower rocky seashores. Can be abundant. Throughout the coast of Europe.