Protected from predators by the anemone's stinging tentacles, the shrimps keep their hosts free of parasites and silt. Like other species of hard corals, leaf corals secrete a mucus that removes sediment from their surfaces and prevents the polyps from being smothered. The rate of secretion is sufficient to remove moderate naturally occurring dustings. However, hard corals cannot handle the tremendous amount of sediment raised by human activities such as dredging of the mangroves and seagrass beds at the southern end of the Belize Barrier Reef. Fishes in disguise.
Most reef fishes are quick-change artists.
The hogfish, is usually orange during the day, blending in with the colorful reef. At night, sleeping on white sand, it turns white, becoming less visible to nighttime predators. When threatened, balloonfish inflate their bodies with water, expanding from the size of a large fist to the size of a soccer ball. Spines sticking out in all directions make the inflated fish an unappetizing meal choice for predators. This interaction is responsible for the white sand found on tropical beaches.