Evolutionary Ecology Laboratories, Department of Biology, Brigham Young University, Provo, Utah, United States of America.
Monte L. Bean Life Science Museum, Brigham Young University, Provo, Utah, United States of America.
PLoS One. 2018 Mar 19;13(3):e0194121. doi: 10.1371/journal.pone.0194121. eCollection 2018.
Mimicry can occur in several contexts, including sexual interactions. In some cases, males mimic females to gain access to potential mates. In contrast, there are relatively few examples of species where females mimic males, and we know very little about what drives these patterns. Two hypotheses have been advanced to explain female mimicry of males. The first is that mimicry is used to reduce harassment of females by males. The second is that mimicry is used to display dominance over other females. In this study, we tested these hypotheses in Brachyrhaphis fishes, wherein females of several species have pigmentation on their anal fin of the same coloration and shape, and in the same location, as the genitalia of males. To test if female mimicry of males reduces male harassment, we experimentally manipulated female pigmentation and observed male preference for females with and without male-like pigmentation. To test the effect that female mimicry of males has on female dominance, we observed how females respond to anal fin pigmentation patterns of companion females. We found that neither of these hypotheses was supported by our data. We conclude that similarities in anal fin pigmentation between male and female Brachyrhaphis fishes is not an adaptation to reduce male harassment or to signal dominance between females. Alternative explanations must exist, including the possibility that these similarities are simply non-adaptive.
拟态可以发生在多个情境中，包括性互动。在某些情况下，雄性通过模仿雌性来获得潜在的配偶。相比之下，只有极少数物种中存在雌性模仿雄性的例子，而且我们对这些模式的驱动因素知之甚少。有两个假说可以解释雌性对雄性的拟态。第一个假说是，拟态是为了减少雄性对雌性的骚扰。第二个假说是，拟态是为了展示对其他雌性的支配地位。在这项研究中，我们在 Brachyrhaphis 鱼类中检验了这些假说，在这些鱼类中，几个物种的雌性在其臀鳍上有与雄性生殖器颜色和形状相同的色素沉着，并且位于相同位置。为了检验雄性拟态是否减少了雄性的骚扰，我们实验性地操纵了雌性的色素沉着，并观察了雄性对具有和不具有雄性样色素沉着的雌性的偏好。为了检验雄性拟态对雌性支配地位的影响，我们观察了雌性对同伴雌性臀鳍色素沉着模式的反应。我们发现，我们的数据并不支持这两个假说。我们得出的结论是，雄性和雌性 Brachyrhaphis 鱼类臀鳍色素沉着的相似性并不是为了减少雄性骚扰或在雌性之间传递支配地位的适应。必须存在其他解释，包括这些相似性可能只是非适应性的可能性。
