Cichlid fishes' famous diversity in body coloration is accompanied by a highly diverse and complex visual system. Although cichlids possess an unusually high number of seven cone opsin genes, they express only a subset of these during their ontogeny, accounting for their astonishing interspecific variation in visual sensitivities. Much of this diversity is thought to have been shaped by natural selection as cichlids inhabit a variety of habitats with distinct light environments. Also, sexual selection might have contributed to the observed visual diversity, and sexual dimorphism in coloration potentially co-evolved with sexual dimorphism in opsin expression. We investigated sex-specific opsin expression of several cichlids from Africa and the Neotropics and collected and integrated data sets on sex-specific body coloration, species-specific visual sensitivities, lens transmission and habitat light properties for some of them. We comparatively analysed this wide range of molecular and ecological data, illustrating how integrative approaches can address specific questions on the factors and mechanisms driving diversification, and the evolution of cichlid vision in particular. We found that both sexes expressed opsins at the same levels-even in sexually dimorphic cichlid species-which argues against coevolution of sexual dichromatism and differences in sex-specific visual sensitivity. Rather, a combination of environmental light properties and body coloration shaped the diversity in spectral sensitivities among cichlids. We conclude that although cichlids are particularly colourful and diverse and often sexually dimorphic, it would appear that natural rather than sexual selection is a more powerful force driving visual diversity in this hyperdiverse lineage.

中文翻译：

---

栖息地光为丽鱼科鱼类视力的快速发展设定了界限，而性选择可以在此范围内进行调节。

慈鲷鱼体色的著名多样性伴随着高度多样化和复杂的视觉系统。尽管丽鱼科鱼具有异常高的七个视锥蛋白基因，但它们在个体发育过程中仅表达其中的一个子集，这说明了它们在视觉敏感性上的惊人种间差异。人们认为这种多样性的大部分是由于自然选择而形成的，因为丽鱼科鱼栖息在具有不同光照环境的多种生境中。同样，性别选择可能有助于观察到的视觉多样性，并且着色中的性二态性可能与视蛋白表达中的性二态性共同发展。我们调查了来自非洲和新热带地区的几种丽鱼科鱼的性别特异性视蛋白表达，并收集了有关性别特异性体色的综合数据集，其中某些物种具有特定于物种的视觉敏感性，晶状体透射率和生境光特性。我们比较分析了这一范围广泛的分子和生态学数据，阐明了整合方法如何解决驱动多样化的因素和机制，特别是丽鱼科动物视力发展的具体问题。我们发现，即使在性二态的丽鱼科鱼物种中，男女都以相同的水平表达视蛋白，这反对性二色性的共同进化和性别特异性视觉敏感性的差异。相反，环境光特性和身体颜色的结合决定了丽鱼科鱼在光谱敏感性方面的多样性。我们得出的结论是，尽管丽鱼科鱼特别多姿多彩，并且经常性两性，