hexacorallians

Hexacorallia, also known as stony corals or true corals, is a subclass of Anthozoa, a class of marine invertebrates belonging to the phylum Cnidaria. These animals are characterized by their radial symmetry and the presence of tentacles arranged in multiples of six. Hexacorallians are typically sessile, meaning they are fixed in one place, and many species are colonial, forming complex structures through the secretion of a hard, calcium carbonate skeleton. This skeletal material forms the basis of coral reefs, which are vital ecosystems supporting a vast array of marine life.

Individual hexacorallians, called polyps, are small, cylindrical organisms with a mouth surrounded by tentacles. They capture small prey using stinging cells called nematocysts. The skeleton secreted by the polyps provides protection and support. While often associated with tropical waters, hexacorallians inhabit diverse marine environments worldwide, from shallow reefs to the deep sea. They play a crucial role in coastal protection and tourism, in addition to their ecological significance. Major groups within Hexacorallia include the scleractinian (stony) corals, anemones, and black corals.