Courting virtual rivals increase ejaculate size in sticklebacks (Gasterosteus aculeatus)
Courting virtual rivals increase ejaculate size in sticklebacks (Gasterosteus aculeatus)
复制标题
求偶虚拟对手会增加刺鱼（Gasterosteus aculeatus）的射精量
DOI：
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复制
发表时间：
2003
影响因子：
2.3
通讯作者：
T. Bakker
中科院分区：
文献类型：
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作者：
M. Zbinden;D. Mazzi;R. Künzler;C. Largiadèr;T. Bakker
精子竞争发生在两个或两个以上的雄性精子竞争使一组特定的卵子受精时。精子竞争的博弈论模型预测，面临精子竞争风险增加的男性将在交配中投入更多的精子。在成对产卵的三棘棘鱼（Gasterosteus aculeatus）中，雄性在求偶期会试图窃取受精（即偷偷摸摸），但当它们是父母时就不会了。因此，邻近雄性的行为可能表明存在精子竞争的风险。在雄性鱼产卵前，我们用电脑动画展示了相同的虚拟棘鱼的两种不同行为：求爱（精子竞争风险高）或照顾后代（精子竞争风险低）。我们发现，在求爱刺激后，雄性投入了更多的精子（绝对和相对于睾丸中可用的精子）。求偶处理与育婴处理的相对投资比平均为1.75。因此，三棘棘鱼似乎通过邻居的行为来评估精子竞争的风险，并相应地调整它们的射精。这一结果表明，精子竞争的进化力量导致了未来风险评估的精确机制。
Sperm competition occurs when sperm of two or more males compete to fertilize a given set of eggs. Game-theory models of sperm competition predict that males, which face an increased risk of sperm competition, will invest more sperm in a mating. In the pair-spawning three-spined stickleback (Gasterosteus aculeatus), males attempt to steal fertilizations (i.e. to sneak) when they are in the courting phase, but not when they are parental. The behaviour of neighbouring males may therefore indicate the risk of sperm competition. We visually confronted males before spawning with computer animations of the same virtual stickleback showing two different behaviours: either courting (high risk of sperm competition) or brood-caring (low risk of sperm competition). We show that males invest significantly more sperm (absolutely and relatively with respect to available sperm in the testes) after the courting stimulus. The relative investment ratio between the courting and the brood-caring treatment was on average 1.75. Three-spined sticklebacks thus seem to assess the risk of sperm competition by the behaviour of neighbours and to adjust their ejaculate accordingly. This result suggests that the evolutionary force of sperm competition has led to precise mechanisms of future risk assessment.