Some species live on minute forms caught by ciliary currents. The sexes are separate. The eggs or sperm are ejected through the mouth. The fertilized egg develops into a planula, which finally settles down somewhere and grows into a single anemone. Asexually they reproduce by pulling apart into 2 halves, or, in some species, small pieces of the pedal disc break off and regenerate into a small anemone.
Anemones form some interesting mutualistic relationships with other organisms.
Many anemones house unicellular algae in their tissues from which they undoubtedly derive some nutrients. Some hermit crabs place anemones on the snail shells in which the crabs live, gaining some protection from the presence of the anemone, while the anemone dines on particles of food dropped by the crab. The clownfish form associations with large anemones. Somehow, these fish do not trigger discharge of the anemone's nematocysts, but if some other fish is so unfortunate as to brush the anemone's tentacles, it is likely to become a meal.