Anemone, Bulb Tentacle Sea Anemone, Entacmaea quadricolor, Anilao, Philippines, Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia.[1] Anthozoa often have large polyps that allow for digestion of larger prey and also lack a medusa stage.[2] As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra.