a hermit crab carefully examines an empty spiral snail shell lying on the wet rocks. The crab reaches out with its claws to test if the shell fits properly. Nearby, a large sea snail slowly glides across the rock surface, carrying its own beautifully patterned shell on its back. Small fish swim around the tidal pool while seaweed sways gently in the shallow water. A starfish clings to a nearby rock observing the scene. the hard outer covering of animals such as snails and crabs that protects their soft bodies