Common Hermit Crab Pagurus bernhardus

It is amazing that, globally, so many different species of hermit crab have evolved to use another animal's protective shell as their own mobile home. Hermit crabs have soft rear bodies and use a sea snail shell, particularly whelk or periwinkle, to protect their body from predators. They curl their rear body and hooked tail around the inside of the shell to walk about and move to a larger shell as they grow. The Common (Marine) Hermit Crab is native to Europe's Atlantic coast including the Baltic and North Seas and as far south as southern Spain. They are often found in tidal rock pools.

Body and legs are a pale or reddish brown. Some show a bluish tint. The largest of the British hermits, the body is some 3.5cm long and the legspan some 15cm. The right claw is larger than the left.