Resumen de Effects of Disturbance on Cenchritis Muricatus (Beaded Periwinkle) Populations on Small Islands in the Bahamas
Disturbance can have multiple impacts on shoreline gastropods. This study compares populations of a common supralittoral snail on islands in exposed and protected areas; the former are subject to much more disturbance from wave action and storm surges. Cenchritis muricatus (Linnaeus, 1758) density was six times higher on protected islands than on exposed islands, representing 2.5 times more biomass. Contrary to expectation, individuals were larger on exposed islands than on protected islands (mean lengths were 26.1 mm and 20.0 mm, respectively); this difference was primarily explained by a significant negative relationship between body size and density coupled with the fact that exposed islands had lower densities. I suggest that periodic large disturbances and oceanographic processes associated with dispersal limit the abundance of C. muricatus on exposed islands, and that larger sizes on exposed islands were probably due to enhanced growth caused by reduced intraspecific competition.
