The False Clownfish (Amphiprion Ocellaris) is one of a number of species of Anemonefish found in parts of the Great Barrier Reef and in Fiji.
Like other species of Anemonefish they live in association with sea anemones. The (highly territorial) anemonefish helps the anemone by defending it from fish (such as butterfly fish) that would otherwise prey on the anemone. In return, the anemonefish finds protection between the stinging tentacles of the anemone. Many fish that would prey on the anemonefish would be stung by the anemone's tentacles (and end up as lunch for the anemone).