Sea anemones are invertebrates that look like flowers, which is where their name comes from. However, sea anemones are animals, not plants, and are related to corals and jellyfish. Sea anemones are polyps made up of a soft cylindrical stalk of a body topped with an oral disc surrounded by tentacles. At their base, they have a single adhesive foot, called a basal disc, which they use to attach to underwater surfaces like rocks or shells. Anemones can have anywhere from a dozen to a few hundred tentacles. Sea anemones are known for their symbiotic relationships with other organisms. They may attach to the shell of a crab but they most noted for their relationship with the clownfish. The clownfish brings food to the anemone in exchange for protection. Most organisms that come into contact with the anemone are paralyzed by the stinging cells from the anemone’s tentacles but the clownfish is one organism that is able to live within the anemone without being eaten or stung. It develops immunity to the anemone and the clownfish must therefore remain with that same anemone for the rest of its life.
There are numerous species of sea anemones that are found throughout the oceans at various depths. These cnidarians come in all colors, decorating a tide pool or reef like a garden of wildflowers. Most anemones usually stay in the same spot until conditions become unsuitable. Anemones are found worldwide in all marine habitats, at various depths. They can be found in a variety of temperature ranges from the cold water of the north Pacific to the warm water of the Caribbean.
Anemones are carnivores. Some feed on tiny plankton, and others feed on fish. The anemone has stinging tentacles, which are triggered by the slightest touch, firing a harpoon-like filament (called a nematocyst which is the same thing that causes a jellyfish sting) into their victim and injecting a paralyzing neurotoxin. The helpless prey is then guided into the mouth by the tentacles. The anemone has a single opening in the center of the oral disc, where food goes in and digested food comes back out.
For the Sea Anemone, a complex process called lateral fusion is what takes place for reproduction. This involves the side of the entity opening up and then an identical part being created that is a second living one. They will release eggs and sperm into the water and then the sperm finds the eggs to fertilize them. This is how they take part in reproduction as well. However, only a very small number of their eggs will survive to the age of maturity. They are able to live attached to rocks or the bottom of the sea for up to 50 years.
Many species of fish, sea stars, and snails will opportunistically feed on anemones. Sea turtles have been known to feed on them, as well. The stinging cells of the anemone help to ward off some predators, but if an animal is big enough or clever enough, it can still make a meal out of an anemone.