Data from: Exposure to parasites increases promiscuity in a freshwater snail

Under the Red Queen hypothesis, outcrossing can produce genetically variable progeny, which may be more resistant, on average, to locally adapted parasites. Mating with multiple partners may enhance this resistance by further increasing the genetic variation among offspring. We exposed Potamopyrgus antipodarum to the eggs of a sterilising, trematode parasite and tested whether this altered mating behaviour. We found that exposure to parasites increased the number of snail mating pairs and the total number of different mating partners for both males and females. Thus our results suggest that, in host populations under parasite-mediated selection, exposure to infective propagules increases the rate of mating and the number of mates.

依据红皇后假说（Red Queen hypothesis），异交可产生具有遗传变异的子代，这类子代平均对本地适应性寄生虫的抗性更强。与多个配偶交配可进一步提升子代的遗传变异水平，进而强化这种抗性。我们将安氏波塔螺（Potamopyrgus antipodarum）暴露于致不育吸虫类寄生虫的虫卵环境中，以此检验寄生虫暴露是否会改变其交配行为。实验结果显示，寄生虫暴露提升了该螺类的交配配对数量，同时增加了雌雄个体的不同交配伙伴总数。综上，本研究结果表明，在受寄生虫介导选择的宿主种群中，接触感染性传播体可提升交配频率与配偶数量。