Laird G, Gwynne D T, Andrade M C B
Biology Department, University of Toronto at Mississauga, Mississauga, Ontario L5L 1C6, Canada.
Proc Biol Sci. 2004 Dec 7;271 Suppl 6(Suppl 6):S402-4. doi: 10.1098/rsbl.2004.0198.
The Australian scaly cricket, Ornebius aperta, can copulate over 50 times with the same partner; the benefits of such extreme repeated copulation are unclear. We support the hypothesis that repeated copulation increases insemination success, as the number of sperm transferred increases with each spermatophore. This probably increases paternity for males, as on average a female mates with over 40 males. Despite intense sperm competition each ejaculate has only a few hundred sperm, orders of magnitude less than in related crickets. We show that all sperm are transferred from each spermatophore in the few seconds before a female removes and eats it. Repeated copulation increases effective copulation duration while a small ejaculate ensures that this strategy is not excessively costly. Thus repeated copulation in these crickets may have arisen as a counter-adaptation to female-imposed limits on copulation.
澳大利亚鳞蟋（Ornebius aperta）能与同一配偶交配50多次；这种极端的重复交配的益处尚不清楚。我们支持这样一种假说，即重复交配会提高受精成功率，因为每次精包传递的精子数量会增加。这可能会增加雄性的父权，因为平均而言，一只雌蟋会与40多只雄蟋交配。尽管存在激烈的精子竞争，但每次射精只有几百个精子，比相关蟋蟀的精子数量少几个数量级。我们发现，在雌蟋移除并吃掉精包之前的几秒钟内，所有精子都从每个精包中传递了出来。重复交配会增加有效交配持续时间，而少量射精确保了这种策略不会成本过高。因此，这些蟋蟀的重复交配可能是作为对雌性施加的交配限制的一种反适应而出现的。
