DIVERGENT REACTIONS TO OLFACTORY FORAGING CUES BETWEEN TWO ECOLOGICALLY SIMILAR, SYMPATRIC HERMIT CRAB SPECIES

Relatively little is known about how sensory differences between species can influence community dynamics and interspecific competition. For animals that rely on chemical (olfactory) cues to forage, subtle differences in the olfactory capabilities between species could influence the foods that the species consume and thus permit coexistence between ecologically similar species. This study identified olfactory foraging cues used by two ecologically similar, sympatric hermit crab species, Clibanarius digueti Bouvier, 1898 and Paguristes perrieri Bouvier, 1895. Additionally, the behavioral chemosensitivities to olfactory cues were compared between the two species. Results show that the two species use different chemical cues to mediate their foraging behaviors, despite similarities in their olfactory chemosensitivity. This sensory differentiation provides a plausible mechanism by which the species relax interspecific food competition enough to permit coexistence.