(full paper is archived in the Miller Library)
Title: Factors in different distribution of ridged and smooth morphologies of Nucella emarginata.
Student Author(s): LaMont, Lauren
Faculty Advisor(s): Denny, Mark
%E Watanabe, Jim
Location: Final papers Biology 175H
Date: June 2002
Abstract: Different distributions of ridged and smooth morphologies of Nucella emarginata are found at wave-exposed and protected sites at China Point in Monterey Bay. A greater number of the ridged morphology was found at the protected site and the smooth at the exposed. Variation in drag coefficients, adhesive force, and crushing force between shell morphologies do not appear to dictate this difference in distribution, although adhesive force is marginally greater in wave exposed whelks. Predation on tethered whelks is greater in the ridged morphology in general than the smooth. However, whelks were eaten more quickly at the protected site, suggesting that wave action’s effect on predators may play a role in the distribution of the two morphologies. In a laboratory experiment, crabs showed no preference between ridged or smooth N. emarginata, with a slight preference for exposed whelks. After 27 days of growth, it was unclear whether differences in shell morphology were present among juveniles hatched from the exposed site.