抄録
Abstract: To evaluate the adaptive significance of shell preference, we investigated the functional roles of gastropod shell species in the intertidal hermit crab Pagurus filholi in terms of tolerance to desiccation stress at high temperature, fecundity and growth rate. Tolerance to desiccation stress(6h at 37°C) did not differ among the shell species occupied and between sexes, and survival rate reached 70-80%. The number of eggs females brooded significantly differed depending on shell size and shell species. Although we did not detect any significant effects of shell size and species on crab growth rate, males tended to grow faster than females, and crabs in large shells tended to grow faster than crabs in small shells. It is suggested that shell preference of P.fiholi has been shaped by the crabs' attempt to maximize growth or fecundity. Sexual differences in shell preference are discussed in terms of the difference in relative importance of rapid growth for the fitness of each sex.
