Spur and groove formations are features that are commonly found on coral reefs. A spur is a narrow, finger-like projection that extends out from the main body of a coral reef, and a groove is a channel or depression that runs parallel to the spur. These formations are typically found on the flanks of coral reefs, and they are thought to be created by the action of waves and currents.
Spurs and grooves can provide habitat for a variety of marine plants and animals, and they can also influence the movement of water and sediment on the reef. Some scientists believe that spurs and grooves may play a role in the development and maintenance of coral reefs, although more research is needed to understand their full role in reef ecology.