Class

Anthozoa (Sea anemones and corals)

Ptilosarcus gurneyi. Photo: (c) Brenna Green, some rights reserved (CC BY-NC-ND)

Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals, soft corals and gorgonians. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being…

— Wikipedia