Photography that shows a sea anemone of green-blue tentacles in turquoise and aquamarine tonalities. Sea anemones are Anthozoa, of the order of the Actinaria, and the sub-class of the Hexacorallia, of brilliant colours, living fixed on sea rocks. As cnidarians, sea anemones are closely related to corals, jellyfish, tube-dwelling anemones and Hydra.