Stoplight Parrotfish Sparisoma viride Fused teeth in the jaws of this large, colorful fish look like a beak (thus, parrotfish). The teeth are so strong they're capable of rasping chunks of coral from a colony. The fish digests the polyps and then excretes small particles of the rocklike skeleton in a white cloud. This scraping and grinding process is a major way in which coral is converted to sand.
