Scleractinia, commonly known as stony corals, are marine invertebrates belonging to the class Anthozoa. They are characterized by their hard calcium carbonate skeletons, which form the structure of coral reefs. These corals play a crucial role in marine ecosystems, providing habitat and shelter for various marine species. Stony corals are primarily found in warm, shallow waters and are vital for reef-building. They engage in a symbiotic relationship with zooxanthellae, microscopic algae that live within their tissues, providing energy through photosynthesis. This relationship is essential for the growth and health of coral reefs, which support diverse marine life.