CREATURE FEATURE - ANEMONES, CORALS AND JELLYFISH
Anemones, jellyfish, corals and their relatives belong to the group called cnidarians. They are simple animals but the variety of their colours and shapes contribute greatly to the beauty of the oceans.
All cnidarians are radially symmetrical, where similar parts of the body are repeated around a central axis. They occur as one of two basic forms - a sessile polyp (a sac-like form) or a drifting medusa (jellyfish form). Some cnidarians may take on both body forms during their life cycle, while others spend their entire lives as one of the two.
Cnidarians are characterised by a centrally located mouth surrounded by numerous tentacles which are used to capture and handle food. The tentacles are armed with a battery of stinging cells, called nematocysts, which fire a harpoon-like structure when touched. Cnidarians are therefore carnivores, catching prey that come within range of their tentacles.
Common cnidarians include sea anemones, such as the beadlet anemone and the flower-like dahlia anemone, dead men's fingers (a soft coral common in the kelp reef habitat), the sea pen (which inhabits sandy areas) and the moon jellyfish.