This example of a soft coral looks like a fan or butterfly. It sways gently in the water but has to be strong enough to resist the currents. Small creatures can easily hide in it and it can grow to be extremely large. Once dead and removed from the water it makes a hard, brittle surface. This piece is from the Caribbean.

The coral reef is like an underwater garden, rich with the different shapes and colours of the corals that grow there and the fish and other creatures that live in this habitat. Corals are found in warm seas, some near the land and some separated from the land by a strip of water, making a reef. Coral reefs are created by tiny animals called hard corals. These grow hard skeletons around their soft bodies, and when one dies another grows on top. Over hundreds of years, the coral colonies join up to make a coral reef.

Coral reefs are popular with tourist divers. Many coral reefs are under threat because of pollution, climate change and because some people collect specimens.