The second part of the series on Guernsey marine life focuses on crustaceans, a group of animals that includes shrimps, prawns, crabs and lobsters. Around 67,000 species have been identified and, while most crustaceans live in water, a few have evolved to live on land, the most familiar being the humble woodlouse.
The distinguishing feature of all these creatures is the possession of a hard outer shell called an exoskeleton. Like a full suit of armour, this provides a protective casing for the soft body of the animal inside. The legs and tail sections have joints to allow for movement and the front pair of legs of most crustaceans has evolved into claws for feeding and defense.