Sperm storage mediated by cryptic female choice for nuptial gifts

Abstract

Polyandrous females are expected to discriminate among males through postcopulatory cryptic mate choice. Yet, there is surprisingly little unequivocal evidence for female-mediated cryptic sperm choice. In species in which nuptial gifts facilitate mating, females may gain indirect benefits through preferential storage of sperm from gift-giving males if the gift signals male quality. We tested this hypothesis in the spider Pisaura mirabilis by quantifying the number of sperm stored in response to copulation with males with or without a nuptial gift, while experimentally controlling copulation duration. We further assessed the effect of gift presence and copulation duration on egg-hatching success in matings with uninterrupted copulations with giftgiving males. We show that females mated to gift-giving males stored more sperm and experienced 17% higher egg-hatching success, compared with those mated to no-gift males, despite matched copulation durations. Uninterrupted copulations resulted in both increased sperm storage and egg-hatching success. Our study confirms the prediction that the nuptial gift as a male signal is under positive sexual selection by females through cryptic sperm storage. In addition, the gift facilitates longer copulations and increased sperm transfer providing two different types of advantage to gift-giving in males.

The shield effect: nuptial gifts protect males against pre-copulatory sexual cannibalism

“…If the gift functions in the way that Bristowe [9] imagined, experimentally removing the gift should (all other things equal) expose the pre-adaptation risk of sexual cannibalism. However, experiments with no-gift males either did not find any sexual cannibalism [13] or at least reported no increased frequency [16][17][18][19].…”

Sexual Cannibalism as a Manifestation of Sexual Conflict

“…Females of the congener A. bruennichi also exert control over relative paternity independently of the duration of copulation by favoring males that courted more (Schneider and Lesmono 2009). Although these studies seem straightforward examples of cryptic female choice (Eberhard 2004b), it remains to be seen whether these findings apply to many other species (see Albo et al 2013). In particular, it is unclear how fitness relevant the option forcryptic female choicewill be in nature.…”

Cryptic Female Choice and Nuptial Prey Gifts in a Spider Model

“…Therefore, much attention has being paid to nuptial gifts as an isolated behavioral trait, and little has been said about their integrative role along the entire reproductive processes. Even those works looking for some connection between nuptial gifts and CFC represent an initial approach to a complex subject (Albo et al 2013;Albo and Peretti in press), bringing interesting indirect evidence into discussion.…”

“…It is "easy" to hypothesize about the adaptive role of nuptial gifts in terms of traditional mate choice, but few works explicitly suggest their role during CFC (Thornhill 1983;Albo et al 2013;Albo and Peretti in press). As mentioned before, it is complex to build a general framework for such a diverse strategy, and apparently, there is no single explanation that could connect nuptial gifts to CFC in a general sense.…”