Delayed copulation as a means of female choice by the hermit crab Pagurus filholi

Abstract

Male hermit crabs perform precopulatory mate-guarding behavior during their reproductive season. As females generally cannot reject guarding attempts by males, male guarding prevents females from inspecting and choosing other male mates. However, as guarding males are often replaced by other males through competition for females during the guarding phase, females may be able to select males by delaying their copulation. To examine the possibility of female choice by hermit crabs, we investigated whether female Pagurus filholi that were being guarded in the field were ready to copulate and spawn. We found that about 30% of females guarded in the field were ready to spawn, indicating that guarded females delayed copulation with their current male. Our results suggest that by delaying copulation females may exploit male–male competition to “choose” dominant males. However, delaying copulation reduced the spawning potential of females. Hence, there is a trade-off between waiting for the opportunity to mate with a dominant male and decreased spawning success if females exploit male–male competition.