Interspecific variation in ejaculate allocation and associated effects on female fitness in seed beetles
Interspecific variation in ejaculate allocation and associated effects on female fitness in seed beetles
复制标题
种子甲虫精液分配的种间变异及其对雌性健康的相关影响
DOI：
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发表时间：
2008
影响因子：
2.1
通讯作者：
G. Arnqvist
中科院分区：
文献类型：
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作者：
J. Rönn;Mari Katvala;G. Arnqvist
当射精的成本很高时，雄性被期望在连续的交配中分配射精资源，以优化其繁殖成功率，这可能对其配偶产生重要影响。在种甲虫（鞘翅目；Bruchidae）中，不同物种的射精大小各不相同，重量从不到雄性体重的1%到高达8%。射精不仅含有精子，还含有一系列其他物质，某些物种的雌性从大量射精中获益。因此，男性射精的分配可能会影响女性的健康。在这里，我们首先描述了7种种子甲虫在连续交配中的雄性射精分配模式。然后，我们评估了这种分配如何影响每个物种的雌性适应性。尽管雌性通常受益于获得大量射精，但考虑到所研究的物种是密切相关的，在射精分配模式和对雌性适合度的影响上观察到的种间差异非常大。我们的分析表明，射精成分的变化是关键，无论是在物种内部还是在物种之间。我们讨论了这种差异的可能原因，并得出结论，在这个进化支系中，男性射精和女性射精物质利用之间的共同进化显然是迅速的。
When ejaculates are costly to produce, males are expected to allocate their ejaculate resources over successive matings in a manner that optimizes their reproductive success and this may have important consequences for their mates. In seed beetles (Coleoptera; Bruchidae), ejaculates vary in size across species from weighing less than 1%, up to as much as 8%, of male body weight. Ejaculates contain not only sperm but also a range of additional substances and females in some species gain benefits from receiving large ejaculates. Male ejaculate allocation may thus affect female fitness. Here, we first characterized the pattern of male ejaculate allocation over successive matings in seven‐seed beetle species. We then assessed how this allocation affected female fitness in each species. Although females generally benefited from receiving large ejaculates, the interspecific variation observed both in ejaculate allocation patterns and in their effects on female fitness was remarkably large considering that the species studied are closely related. Our analyses suggest that variation in ejaculate composition is the key, both within and across species. We discuss possible causes for this variation and conclude that coevolution between male ejaculates and female utilization of ejaculate substances has apparently been rapid in this clade.