Description
Sea anemone, any member of the invertebrate order Actiniaria (class Anthozoa, phylum Cnidaria), soft-bodied, primarily sedentary marine animals resembling flowers. They are found from the tidal zone of all oceans to depths of more than 10,000 metres (about 33,000 feet). Some live in brackish water. They are largest, most numerous, and most colourful in warmer seas. The colourful Tealia are found in temperate regions.
The nearly 1,000 species vary in size from a few millimetres (a fraction of an inch) in diameter and length to about 1.5 metres (about 5 feet) in diameter. The largest sea anemones—also the largest cnidarians—are of the genus Stichodactyla.