Rodriguez-Silva Rodet, Spikes Montrai, Monsisbay Manuel Iturriaga, Schlupp Ingo
Department of Biology University of Oklahoma Norman Oklahoma USA.
Departamento de Colecciones Zoológicas Instituto de Ecología y Sistemática La Habana Cuba.
Ecol Evol. 2023 Jan 24;13(1):e9768. doi: 10.1002/ece3.9768. eCollection 2023 Jan.
Color polymorphism can be maintained in natural populations by natural selection or sexual selection. In this study, we use two different approaches to test which of these evolutionary mechanisms may explain the presence of color polymorphism in the Cuban Limia (), an endemic livebearing fish from Cuba. First, we investigate the role of sexual selection using traditional binary choice tests looking at both female and male preferences relative to varying degrees of black spotting in stimulus mates. Second, we assess the role of natural selection by analyzing the frequency and geographic distribution of black-spotted and nonspotted morphs of in natural populations from Cuba. The frequency of black-spotted morphs is significantly higher in brackish and saltwater environments compared with freshwater habitats, which could be related to higher predation pressure in coastal ecosystems compared with purely freshwater environments. Our results suggest that habitat variation is the most important factor in maintaining color polymorphism in . Salinity levels could be indirectly responsible for maintaining different color morphs in this species, likely due to the regulatory effect of saline gradients on predation regimes.
颜色多态性可以通过自然选择或性选择在自然种群中得以维持。在本研究中，我们采用两种不同方法来测试这些进化机制中的哪一种可以解释古巴米诺鱼（一种来自古巴的特有胎生鱼类）颜色多态性的存在。首先，我们使用传统的二元选择测试来研究性选择的作用，观察雌性和雄性相对于刺激配偶不同程度黑斑的偏好。其次，我们通过分析来自古巴自然种群中黑斑和无斑形态的频率和地理分布来评估自然选择的作用。与淡水栖息地相比，咸淡水和咸水环境中黑斑形态的频率显著更高，这可能与沿海生态系统中比纯淡水环境更高的捕食压力有关。我们的结果表明，栖息地变化是维持古巴米诺鱼颜色多态性的最重要因素。盐度水平可能间接导致该物种维持不同的颜色形态，这可能是由于盐度梯度对捕食模式的调节作用。
