NEUROPHYSIOLOGICAL CORRELATES OF THE BEHAVIORAL-RESPONSE TO LIGHT IN THE SEA-ANEMONE ANTHOPLEURA-ELEGANTISSIMA

Neurophysiological responses to light in Anthopleura elegantissima do not involve the ectodermal slow system 1 (SS1). Activities in both the endodermal slow system 2 (SS2) and the through conducting nerve net ( TCNN) change when the lighting changes, but the response is not consis tent. Thus, photoreception in A. elegantissima probably occurs in the endoderm because SS2 and the TCNN are involved and SS1 is not. We hypo thesize either that the photoreception occurs in sensory cells in a lo cal nerve net, with the information then being transmitted to the musc les, or that the muscles themselves are light sensitive. In either cas e, the TCNN and SS2 become involved after the transduction, and as a c onsequence-rather than the cause-of muscular activation. The conductin g systems of zooxanthellate specimens have a higher frequency of activ ity than those of apozooxanthellate individuals.