Guarded encounters: how postcopulatory contact leads to mate recognition in spiders

Abstract

Individuals can benefit from mating with different partners, with females gaining both direct and genetic benefits, and males increasing the number of offspring. Thus, the ability to identify and preferentially mate with new partners should increase individual reproductive success. Here, we aim to determine whether females and males of the marbled cellar spider, Holocnemus pluchei, a species with a promiscuous mating system and postcopulatory mate guarding, can recognize the individual with which they previously mated. We compared the likelihood of males engaging in courtship, the likelihood of females mating a second time and the likelihood of female mating interruptions with the same mates versus new mates. Considering that possible mate recognition may occur during copulation and/or during the postcopulatory guarding period, we conducted a full factorial experiment that consideredboth the presence or absence of a new male and the presence or absence of postcopulatory guarding. Our results support the hypothesis that both female and male H. pluchei recognize individual mates, as the identity of the second partner (same or new) significantly affected courtship, remating and copulation interruption. Our results indicate that mate recognition exists in both sexes and that postcopulatory guarding plays a crucial role for males in this process. Thus, these findings contribute to a broader understanding of the mechanisms of sexual selection and reproductive strategies in promiscuous species, highlighting the importance of individual recognition for optimizing reproductive success.