Spinecheek anemonefish (Premnas biaculeatus) hiding in the tentacles of a bulb tentacle sea anemone (Entacmaea quadricolor). The anemonefish has a symbiotic relationship with the sea anemone. The sea anemone provides the anemonefish a safe haven by protecting it from predators through its stinging tentacles. The fish is immune to the sting and cleans the anemone by feeding on parasites such as algae and zooplankton. This fish can reach up to 17cm in length. Photographed off Maratua Island, in the Sulawesi Sea, Indonesia.