Juvenile yellow boxfish (Ostracion cubicus). This fish inhabits coral reefs in the tropical Indo- Pacific region. It has bony hexagonal plates under its skin and a toxic mucus to protect it from predators. It feeds mainly on algae, but also takes molluscs, sponges and crustaceans. It can reach a length of up to 45 centimetres. Photographed in Tulamben, Bali, Indonesia.