Regional variation in preference for gastropod shell species in the hermit crab Pagurus filholi

Abstract

The preference for two shell species, Monodonta labio form confusa and Thais clavigera, was compared between two populations of the hermit crab Pagurus filholi from Oura Bay, Shimoda, central Japan and from Hakodate Bay, Hakodate, northern Japan. Hermit crabs from Oura Bay preferred T. clavigera to M. labio form confusa, whereas crabs from Hakodate Bay preferred M. labio form confusa. The shell of T. clavigera was more effective against desiccation and high temperature stress but heavier than M. labio form confusa. The preference of P. filholi from Oura Bay for T. clavigera may be attributable to the greater requirement for protection against higher physical stresses, even though a higher energetic cost related to the shell weight is incurred.