Selective effects of disturbance on populations of sea anemones from northern Baja California, Mexico

Abstract

Effects of desiccation and sand burial on the survival and behavior of intertidal sea anemones Anthopleura elegantissima from northern Baja California were studied experimentally by comparing: (1) clonal and solitary forms; (2) aggregated and "wandering" (isolated module) configurations of the clonal form; and (3) large and small individuals of the solitary form. Wandering modules were more susceptible to desiccation than were the aggregated clonal anemones, and wandering anemones moved more in response to desiccation than did aggregated ones. Both wandering and aggregated anemones showed little mobility when faced with sand burial. Small solitary anemones were more susceptible to desiccation than were large ones. They increased their mobility when confronted with this disturbance; larger specimens did not. Small solitaries reacted to sand burial by increasing their mobility; large ones did not increase their mobility but avoided burial by elongating their column.