Coral reef a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the "topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors
Open brain coral Open brain coral The open brain coral ("Trachyphyllia geoffroyi") is a brightly colored free-living coral species in the family Merulinidae. It is the only species in the monotypic genus Trachyphyllia and can be found throughout the Indo-Pacific. Open brain corals can be solitary or colonial. They are small corals, rarely reaching over 20 cm in diameter. They are free-living and exhibit a flabello-meandroid growth form, meaning they have distinct valley regions separated by walls. In colonial forms, the valley regions can contain multiple individual polyps. Complexity of valley regions can range; some are hourglass shaped while other cans be highly