Napoleon wrasse (Cheilinus undulatus). Also called the humphead wrasse, this is the largest of the wrasses, reaching a length of over three metres. It is found on coral reefs throughout the tropical Indo-Pacific region. It is mainly carnivorous, feeding on molluscs and crustaceans. Elderly individuals develop a large fatty hump above their eyes. Photographed in Palau, a group of islands in Micronesia, in the Western Pacific Ocean.