When attacked by a sea star, an anemone called Stomphia releases itself and contracts its body to swim away.
Cnidarians: Anemone Swims Away From Sea Star
Next Generation Science Standards for this Video
The sea star, Dermasterias, often preys on the anemone, Stomphia. As a behavioral adaptation to avoid this predation, Stomphia has evolved the ability to release from the bottom and swim away. This is unusual behavior for an anemone.