(full paper is archived in the Miller Library)
Title: Implications of Tegula shell utilization patterns in the intertidal hermit crabs Pagurus samuelis and Pagurus granosimanus, in the Monterey Bay
Student Author(s): Kim, Connie
Faculty Advisor(s): Watanabe, Jim
Location: Final Papers Biology 175H
Date: June 1994
Abstract: Pagurus samuelis is found consistently higher than Pagurus granosimanus in the rocky intertidal of China Point in Monterey Bay. The adequacy and availability of Tegula shells to P. samuelis and P. granosimanus was studied to investigate the possibility of competition for shells as a mechanism of maintaining tidal height segregation. The investigation was done in three portions: a mark and release study of live snails to directly find the rate of supply of new shells, creating a shell adequacy index using crab weight and shell diameter, and a comparison of the shell adequacy of P. samuelis and P. granosimanus where they co-occur and occur separately. Although the mark and release study yielded no mortality after six weeks, data from the shell adequacy index suggests that large P. samuelis and P. granosimanus are not shell limite. The interspecific competition for shells was not significantly different from intraspecific competition, and therefore does not play a major role in maintaining tidal segregation.