A shrimp cleans a moray eel's mouth, off Tulamben, on the Indonesian resort island of Bali May 14, 2011. Cleaner shrimp is a generic term for any swimming decapod crustacean that cleans other organisms of parasites. This symbiotic relationship benefits the fish by having parasites removed from them, and the shrimp gets its food. Picture taken May 14, 2011. REUTERS/David Loh (INDONESIA - Tags: ENVIRONMENT ANIMALS IMAGES OF THE DAY)