Toft S, Albo M J
Department of Bioscience, Aarhus University, Aarhus C, Denmark.
J Evol Biol. 2015 Feb;28(2):457-67. doi: 10.1111/jeb.12581. Epub 2015 Jan 22.
In species where females gain a nutritious nuptial gift during mating, the balance between benefits and costs of mating may depend on access to food. This means that there is not one optimal number of matings for the female but a range of optimal mating numbers. With increasing food availability, the optimal number of matings for a female should vary from the number necessary only for fertilization of her eggs to the number needed also for producing these eggs. In three experimental series, the average number of matings for females of the nuptial gift-giving spider Pisaura mirabilis before egg sac construction varied from 2 to 16 with food-limited females generally accepting more matings than well-fed females. Minimal level of optimal mating number for females at satiation feeding conditions was predicted to be 2-3; in an experimental test, the median number was 2 (range 0-4). Multiple mating gave benefits in terms of increased fecundity and increased egg hatching success up to the third mating, and it had costs in terms of reduced fecundity, reduced egg hatching success after the third mating, and lower offspring size. The level of polyandry seems to vary with the female optimum, regulated by a satiation-dependent resistance to mating, potentially leaving satiated females in lifelong virginity.
在交配时雌性会获得营养丰富的婚飞礼物的物种中，交配的收益与成本之间的平衡可能取决于食物的获取情况。这意味着对于雌性来说，不存在一个最优的交配次数，而是存在一系列最优的交配次数范围。随着食物供应量的增加，雌性的最优交配次数应该从仅为使卵子受精所需的次数变化到同时为产出这些卵子所需的次数。在三个实验系列中，给予婚飞礼物的蜘蛛奇异盗蛛（Pisaura mirabilis）的雌性在构建卵囊之前的平均交配次数从2次到16次不等，食物受限的雌性通常比营养良好的雌性接受更多的交配。在饱足喂养条件下，预测雌性最优交配次数的最低水平为2 - 3次；在一项实验测试中，中位数为2次（范围为0 - 4次）。多次交配在繁殖力增加和直到第三次交配时卵孵化成功率提高方面带来了好处，但在繁殖力降低、第三次交配后卵孵化成功率降低以及后代体型变小方面存在成本。一妻多夫的程度似乎随雌性的最优情况而变化，受饱足依赖性交配抗性调节，这可能使饱足的雌性终身保持处女状态。
