(full paper is archived in the Miller Library)
Title: The acontia of Metridium senile and their relationship to predation by Dermasterias imbricata
Student Author(s): Golde, Helen M.
Faculty Advisor(s): Wagenbach, Gary
Location: Research Reports Carleton College Biology 212
Date: November 1983
Abstract: Metridium senile extrude nematocyst laden acontia when disturbed which have been shown to deter predation by Aeolidia papillosa. This response was studied in relation to another predator, Dermasterias imbricata. Anemones of varying sizes were stimulated on the column and on the oral disk with both a blunt probe and a D. imbricata. The anemones and the starfish were also allowed to freely interact. M. senile were found to react more quickly to columnar than to oral stimulation. They were also found to react more quickly to stimulation with the starfish than with a blunt probe. There is no correlation between the speed of the reaction and the size of the anemone. The release of acontia by M. senile does seem to deter predation by D. imbricata.