BOURDEAU, P.E.; Stony Brook University: Integration of anti-predator behavior and morphology in three species of rocky intertidal gastropods

Prey organisms have evoloved behavioral and morphological defenses that reduce their susceptibility to predation. However, until recently the joint evolution of anti-predator behavior and morphology has received little attention. I examined the relationship between anti-predator behavior and morphology across three species of rocky intertidal gastropods. Whelks in the genus Nucella exposed to predator cues exhibited interspecific differences in anti-predator behavior, which were dependent on predator functional type. Thin-shelled species showed a stronger behavioral response to a shell-crushing crab predator than more well-defended, thick-shelled species. This relationship changed when snails were exposed to a non-crushing sea star predator. Intraspecific differences in anti-predator behavior were related to body size and shell thickness. These results suggest that mulitple predators may have variable indirect effects on rocky intertidal assemblages by modifying the behavior of their prey.