A sea anemone belongs to the Kingdom Animalia (animals), Phylum Coelenterata (corals, jellyfish, sea anemones), Class Anthozoa (flower-like animals), and Order Actiniaria.
Sea anemones live in marine environments including coral reefs, deep oceans, and shallow coastal waters. They are invertebrates meaning they have no skeleton. They look like flowers but are carnivores that consume fish, mussels, zooplankton, and worms. They prey on food using their tentacles that are lined with nematocysts (stinging cells). Clown fish are noted for making their homes with anemones. The clown fish is not harmed by the sea anemone's stinging tentacles. There are over 1000 species of sea anemones. Most are 1-4 inches but some are as large as 6 feet. They are all radially symmetrical with a column-shaped body and mouth surrounded by tentacles. Many salt water aquarium enthusiasts have sea anemones in their tanks.