True Sea Anemones are predators, using their stinging tentacles to capture crabs, fish, mollusks, sea cucumbers, and other invertebrates. The stinging cells paralyze the prey and the tentacles then pass the prey to the mouth. The stinging tentacles provide defense from some predators, and the Anemone can roll its tentacles and disc inward forming a stumpy blob that is difficult for predators to attack. Even with these defense mechanisms, True Sea Anemones are eaten by fish, starfish, gastropods, nudibranchs, and Loggerhead Sea Turtles. True Sea Anemone species may also be zooxanthellate, indicative that they have a symbiotic relationship with single-cell dinoflagellates, the zooxanthellae. Zooxanthellae live within certain Coral Polyps, Jellyfish, Nudibranchs and Sea Anemones. The zooxanthellae produce energy, during daylight, by means of photosynthesis with the energy being passed along to their hosts, sometimes providing up to 90% of the host’s total energy needs. In return, the host provides nutrients, carbon dioxide, and a secure, sunlit, platform. True Sea Anemones may reproduce sexually, or asexually, by budding or fission. With very few exceptions, True Sea Anemones do not form relationships with fish, such as Clownfish or Anemonefish, as other Anemones do in the Indo-Pacific.

True Sea Anemones are generally found attached to hard substrate, though their attachment is not permanent or fixed in one location. They can crawl slowly, while remaining attached. Also, many species can detach from the substrate and drift or roll, to escape predators. They range in depth from the intertidal zone to depths exceeding 1000 m (3,280 feet). They are found worldwide, in tropical and temperate waters. There are 340 species in the Actiniidae Family of which 12 are found along Mexico’s Pacific Coast.