PDF(Pubmed)
Abstract：
BACKGROUND: The mechanosensory lateral line system is an important sensory modality in fishes, informing multiple behaviours related to survival including finding food and navigating in dark environments. Given its ecological importance, we may expect lateral line morphology to be under disruptive selection early in the ecological speciation process. Here we quantify the lateral line system morphology of two ecomorphs of the cichlid fish Astatotilapia calliptera in crater Lake Masoko that have diverged from common ancestry within the past 1,000 years.
RESULTS: Based on geometric morphometric analyses of CT scans, we show that the zooplanktivorous benthic ecomorph that dominates the deeper waters of the lake has large cranial lateral line canal pores, relative to those of the nearshore invertebrate-feeding littoral ecomorph found in the shallower waters. In contrast, fluorescence imaging revealed no evidence for divergence between ecomorphs in the number of either superficial or canal neuromasts. We illustrate the magnitude of the variation we observe in Lake Masoko A. calliptera in the context of the neighbouring Lake Malawi mega-radiation that comprises over 700 species.
CONCLUSIONS: These results provide the first evidence of divergence in this often-overlooked sensory modality in the early stages of ecological speciation, suggesting that it may have a role in the broader adaptive radiation process.
RESULTS: Based on geometric morphometric analyses of CT scans, we show that the zooplanktivorous benthic ecomorph that dominates the deeper waters of the lake has large cranial lateral line canal pores, relative to those of the nearshore invertebrate-feeding littoral ecomorph found in the shallower waters. In contrast, fluorescence imaging revealed no evidence for divergence between ecomorphs in the number of either superficial or canal neuromasts. We illustrate the magnitude of the variation we observe in Lake Masoko A. calliptera in the context of the neighbouring Lake Malawi mega-radiation that comprises over 700 species.
CONCLUSIONS: These results provide the first evidence of divergence in this often-overlooked sensory modality in the early stages of ecological speciation, suggesting that it may have a role in the broader adaptive radiation process.
摘要：
背景：机械感觉侧线系统是鱼类的重要感觉形态，告知与生存有关的多种行为，包括寻找食物和在黑暗环境中导航。鉴于其生态重要性，我们可能期望侧线形态在生态物种形成过程的早期处于破坏性选择之下。在这里，我们量化了火山口Masoko湖中的丽鱼科鱼Astatototilapiacalliptera的两种生态形态的侧线系统形态，它们在过去1000年中与共同祖先不同。
结果：基于CT扫描的几何形态分析，我们表明，在湖泊深层水域占主导地位的浮游动物底栖生态形态具有较大的颅侧线运河孔隙，相对于在较浅的水域中发现的以近岸无脊椎动物为食的沿海生态形态。相比之下,荧光成像显示，没有证据表明在浅层或管神经管的数量上，ecomorphs之间存在差异。我们说明了在邻近的马拉维湖大辐射的情况下，我们在MasokoA.calliptera湖中观察到的变化幅度，该辐射包括700多种物种。
结论：这些结果提供了在生态物种形成的早期阶段这种经常被忽视的感觉形态差异的第一个证据，这表明它可能在更广泛的适应性辐射过程中发挥作用。
结果：基于CT扫描的几何形态分析，我们表明，在湖泊深层水域占主导地位的浮游动物底栖生态形态具有较大的颅侧线运河孔隙，相对于在较浅的水域中发现的以近岸无脊椎动物为食的沿海生态形态。相比之下,荧光成像显示，没有证据表明在浅层或管神经管的数量上，ecomorphs之间存在差异。我们说明了在邻近的马拉维湖大辐射的情况下，我们在MasokoA.calliptera湖中观察到的变化幅度，该辐射包括700多种物种。
结论：这些结果提供了在生态物种形成的早期阶段这种经常被忽视的感觉形态差异的第一个证据，这表明它可能在更广泛的适应性辐射过程中发挥作用。
