Lomax Justin L, Carlson Rachel E, Wells Judson W, Crawford Patrice M, Earley Ryan L
Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA.
Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA.
Zoology (Jena). 2017 Jun;122:38-45. doi: 10.1016/j.zool.2017.02.004. Epub 2017 Feb 20.
The mangrove rivulus, Kryptolebias marmoratus, is one of two known vertebrate species with preferentially self-fertilizing hermaphrodites. Males also exist, and can outcross with hermaphrodites. Outcrossing events vary across wild populations and occur infrequently in laboratory settings. This study sought to add dimension to our understanding of mangrove rivulus reproductive habits by probing the effects of male presence on hermaphroditic unfertilized egg production. Specifically, we quantified egg production of solitary hermaphrodites compared to hermaphrodites exposed to males and exposed to other hermaphrodites. Hermaphrodites tended to produce more fertilized eggs in the presence of males but unfertilized eggs were produced relatively rarely and did not vary significantly among treatments. The probability that hermaphrodites would produce eggs changed as a function of genetic dissimilarity with their partner and in a season-dependent manner. In the fall, the probability of laying eggs decreased as a function of increased genetic dissimilarity, regardless of the sex of the partner. In the winter/spring, however, the probability of laying eggs increased markedly with increased genetic dissimilarity, regardless of the sex of the partner. Our findings indicate that reproductive decisions are modulated by factors beyond male presence, and we discuss a number of alternative hypotheses that should be tested in future studies.
红树鳉鱼（Kryptolebias marmoratus）是已知的两种具有优先自体受精的雌雄同体的脊椎动物之一。雄性也存在，并且可以与雌雄同体进行异体受精。异体受精事件在野生种群中各不相同，在实验室环境中很少发生。本研究旨在通过探究雄性存在对雌雄同体未受精卵产生的影响，加深我们对红树鳉鱼繁殖习性的理解。具体而言，我们对单独的雌雄同体与暴露于雄性和暴露于其他雌雄同体的雌雄同体的产卵量进行了量化。雌雄同体在有雄性存在时往往会产生更多的受精卵，但未受精卵相对较少产生，并且在各处理之间没有显著差异。雌雄同体产卵的概率随着与其配偶的遗传差异以及季节依赖性而变化。在秋季，产卵概率随着遗传差异的增加而降低，无论配偶的性别如何。然而，在冬季/春季，产卵概率随着遗传差异的增加而显著增加，无论配偶的性别如何。我们的研究结果表明，繁殖决策受到雄性存在之外的因素的调节，并且我们讨论了一些应在未来研究中进行测试的替代假设。
