Red saddleback anemonefish (Amphiprion ephippium) in its host anemone. This fish inhabits coral reefs of the eastern Indian Ocean. It lives in the stinging tentacles of a sea anemone, to which it is immune. This affords it protection against predators, which would be stung by the anemone. The fish picks parasites from its host anemone, thus forming a symbiotic (mutually beneficial) relationship with it. The saddle anemonefish can reach a length of nearly 15 centimetres. Photographed in the Andaman Sea, Thailand.