Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa.
J Fish Biol. 2020 Jul;97(1):75-82. doi: 10.1111/jfb.14327. Epub 2020 Apr 29.
Cichlids are one of the most diverse and colourful groups of freshwater fishes in the world. Despite much investigation, the factors that promote speciation in these fishes are still uncertain. However, previous studies suggest that sexual selection on male colour is one of the main drivers of speciation among these fishes. Metriaclima estherae is a polymorphic cichlid species from Lake Malawi, and thus provides an ideal model for the investigation of the importance of colour as a species recognition cue. M. callainos is a closely related and morphologically similar species, with male colour pattern very similar to that of M. estherae. We tested female choice by giving females of the two species a choice between conspecific and heterospecific males in the presence and absence of visual (colour) and chemical cues. The results show that females of M. callainos were able to reliably recognize conspecific males, even when colour was eliminated as a cue. However, females of M. estherae did not prefer conspecific males, although they were able to discriminate between red and blue conspecific colour morphs by using chemical cues. These results suggest that species recognition cues may differ even among closely related species of cichlid fish, and that female preferences for male coloration may be weak in certain species.
慈鲷是世界上最多样化和最具色彩的淡水鱼类之一。尽管进行了大量的研究，但促进这些鱼类物种形成的因素仍不确定。然而，先前的研究表明，雄性颜色的性选择是这些鱼类物种形成的主要驱动因素之一。梅氏丽鱼是来自马拉维湖的一种多态性慈鲷物种，因此为研究颜色作为物种识别线索的重要性提供了理想的模型。M. callainos 是一种密切相关且形态相似的物种，其雄性颜色图案与 M. estherae 非常相似。我们通过在有和没有视觉（颜色）和化学线索的情况下，让两种鱼类的雌性在同种和异种雄性之间做出选择，来测试雌性的选择。结果表明，M. callainos 的雌性能够可靠地识别同种雄性，即使颜色作为线索被消除。然而，M. estherae 的雌性并不偏爱同种雄性，尽管它们能够通过化学线索区分红色和蓝色的同种颜色形态。这些结果表明，即使是在密切相关的慈鲷鱼类物种中，物种识别线索也可能存在差异，并且某些物种中雌性对雄性颜色的偏好可能较弱。
