Bumphead Parrotfish

Photo: Mark Rosenstein · CC BY-NC

Schools of bumphead parrotfish graze the shallow reef terrace at Tutuba, their massive beaked jaws crunching through dead coral and limestone to extract algae, producing spectacular clouds of white sand from their digestive systems — a single large individual generates several hundred kilograms of sand annually. They feed in coordinated dawn raids, ramming corals with their bulbous foreheads to dislodge chunks before grinding them down.