Bumphead Parrotfish

Photo: Mark Rosenstein · CC BY-NC

Schools of up to 40 bumphead parrotfish — the ocean's largest parrotfish species — cruise the outer reef at Nosy Tanikely excavating coral with their reinforced beaks and excreting fine white sand. A single individual may produce 90 kilograms of sand per year, directly building the island's beaches. Their dawn aggregations on the shallow reef crest are one of the Indian Ocean's great wildlife spectacles — the sound of them feeding is audible without a mask.