Coexistence in a hermit crab species ensemble.

Abstract

The shell exploitation of hermit crabs inhabiting a subtidal region of Beaufort Harbor (N. C.) was studied to determine the importance of shell resource partitioning in allowing the coexistence of the hermit crabs. The three most abundant species (Pagurus annulipes, P. longicarpus, and P. pollicaris) partition the size range. The size ratio between the larger species (P. pollicaris and P. longicarpus) was 1.7 and the size ratio between the smaller species (P. annulipes and P. longicarpus) was only 1.2. Differences in shell species utilization were significant only for the smaller species (P. annulipes and P. longicarpus). Specimens of four other hermit crab species were collected (Pagurus brevidactylus, Pagurus impressus, Paguristes hummi, and Petrochirus diogenes). Individuals of these species are more prevalent offshore. In Beaufort Harbor they use relatively small shells or shells which tend to be overlooked or shunned by the other species.Experiments on shell selection, interspecific fighting, and sub...