Abstract

Ultraviolet (UV) A signals (320–400 nm) are important in mate choice in numerous species. The sensitivity for UV signals is not only assumed to be costly, but also expected to be a function of the prevailing ecological conditions. Generally, those signals are favored by selection that efficiently reach the receiver. A decisive factor for color signaling is the lighting environment, especially in aquatic habitats, as the visibility of signals, and thus costs and benefits, are instantaneously influenced by it. Although ecological aspects of color signal evolution are relatively well-studied, there is little data on specific effects of environmental UV-light conditions on signaling at these shorter wavelengths. We studied wild-caught gravid female 3-spined sticklebacks Gasterosteus aculeatus of 2 photic habitat types (tea-stained and clear-water lakes), possessing great variation in their UV transmission. In 2 treatments, tea-stained and clear-water, preferences for males viewed under UV-present (UV+) and UV-absent (UV–) conditions were tested. A preference for males under UV+ conditions was found for females from both habitat types, thus stressing the significance of UV signals in stickleback’s mate choice decisions. However, females from both habitat types showed the most pronounced preferences for males under UV+ conditions under clear-water test conditions. Moreover, reflectance measurements revealed that the carotenoid-based orange-red breeding coloration in wild-caught males of both habitat types differed significantly in color intensity (higher in clear-water males) and hue (more red shifted in clear-water males) while no significant differences in UV coloration were found. The differential reflection patterns in longer wavelengths suggest that sticklebacks of both habitat types have adapted to the respective water conditions. Adaptations of UV signals in a sexual context to ambient light conditions in both behavior and coloration seem less evident.

中文翻译：

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照明环境对来自两种不同光生境的刺鱼社会偏好的影响。一、野生捕捞雌性的交配偏好

摘要

紫外线 (UV) A 信号 (320–400 nm) 在众多物种的配偶选择中很重要。紫外线信号的灵敏度不仅被认为是昂贵的，而且还被认为是普遍生态条件的函数。通常，这些信号受到有效到达接收器的选择的青睐。颜色信号的一个决定性因素是照明环境，尤其是在水生栖息地，因为信号的可见性以及成本和收益会立即受到它的影响。尽管对颜色信号演化的生态方面进行了相对深入的研究，但关于环境紫外线条件对这些较短波长信号的具体影响的数据很少。我们研究了野生捕获的妊娠雌性三刺棘鱼Gasterosteus aculeatus2 种光生境类型（茶色湖泊和清水湖泊），它们的紫外线透射率差异很大。在茶渍和清水两种处理中，测试了在有紫外线 (UV+) 和无紫外线 (UV–) 条件下观察到的男性的偏好。两种栖息地类型的雌性在紫外线 + 条件下都偏爱雄性，因此强调了紫外线信号在棘鱼的配偶选择决定中的重要性。然而，在清水测试条件下，在紫外线+条件下，来自两种栖息地类型的雌性对雄性表现出最明显的偏好。而且，反射率测量显示，两种栖息地野生捕获的雄性基于类胡萝卜素的橙红色繁殖着色在颜色强度（清水雄性较高）和色调（清水雄性中更红移）方面差异显着，而没有显着差异发现紫外线着色的差异。较长波长的差异反射模式表明两种栖息地类型的刺鱼已经适应了各自的水条件。性环境中的紫外线信号在行为和颜色方面对环境光条件的适应性似乎不太明显。