Bumphead Parrotfish

Photo: ca_photo_hobbyist · CC BY-NC

Schools of bumphead parrotfish — some individuals exceeding a metre — graze along Sumilon's reef crest at dawn, scraping coral with their fused beak-like teeth and excreting the calcium carbonate as fine white sand. Their crunching feeding sounds carry underwater for dozens of metres, and dawn dives offer the best chance of intercepting the school before it disperses into deeper water.