Complex and Modifiable Behavior Patterns Incalliactisandstomphia

Three behavior patterns in sea anemones are analyzed in relation to the receptors, elfectors, and co-ordinating s)stems required for their perfomance: Calliactis responding to molluscan “shell-factor.” Stomphia swimming to starfish and to electrical stimulation. Stomphia transferring to shells of its commensal Modiolus modiolus. These complex purposive acts are triggered and controlled by the excitation of chemoreceptors. Co-ordinating nervous components have not been identified. These specific responses offer possibilities for tests on learning for which unequivocal evidence does not exist in coelenterates.