Reinhardt Klaus, Siva-Jothy Michael T
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom.
Am Nat. 2005 Jun;165(6):718-23. doi: 10.1086/430010. Epub 2005 Apr 6.
We show that males of the house cricket Acheta domesticus regularly expel sperm packages (spermatophores) independently of copulation and at a rate that is not affected by the presence of females. We then show for the first time that the age of sperm affects their likelihood of being stored by females after copulation; younger sperm were overrepresented in the female sperm storage organ and therefore in the sperm population used for fertilization. Our results suggest that the reproductive success of males may increase if they deliver ejaculates with young sperm, and the results may explain why the males of several species are regularly observed to discard ejaculates. Our results also suggest that phenomena such as female multiple mating, paternity bias, and/or exaggerated ejaculate sizes may be related to the advantage both genders gain by using young sperm.
我们发现，家蟋蟀（Acheta domesticus）的雄性会定期排出精子包（精荚），且这种行为与交配无关，其排出速率也不受雌性存在的影响。然后，我们首次表明，精子的年龄会影响其在交配后被雌性储存的可能性；较年轻的精子在雌性精子储存器官中占比过高，因此在用于受精的精子群体中也占比过高。我们的研究结果表明，如果雄性排出含有年轻精子的精液，其繁殖成功率可能会提高，这一结果或许可以解释为何经常观察到几种物种的雄性会丢弃精液。我们的研究结果还表明，诸如雌性多次交配、父权偏差和/或夸张的射精量等现象，可能与两性使用年轻精子所获得的优势有关。
