Data for: Long-wavelength-sensitive (lws) opsin gene expression, foraging and visual communication in coral reef fishes

Coral reef fishes are diverse in ecology and behaviour and show remarkable colour variability. Investigating the visual pigment gene (opsin) expression in these fishes makes it possible to associate their visual genotype and phenotype (spectral sensitivities) to visual tasks, such as feeding strategy or conspecific detection. By studying all major damselfish clades (Pomacentridae) and representatives from five other coral reef fish families, we show that the long-wavelength-sensitive (lws) opsin is highly expressed in algivorous and less or not expressed in zooplanktivorous species. Lws is also upregulated in species with orange/red colours (reflectance >520 nm) and expression is highest in orange/red-coloured algivores. Visual models from the perspective of a typical damselfish indicate that sensitivity to longer wavelengths does enhance the ability to detect the red to far-red component of algae and orange/red-coloured conspecifics, possibly enabling social signalling. Character state reconstructions indicate that in the early evolutionary history of damselfishes, there was no lws expression and no orange/red coloration. Omnivory was most often the dominant state. Although herbivory was sometimes dominant, zooplanktivory was never dominant. Sensitivity to long wavelength (increased lws expression) only emerged in association with algivory but never with zooplanktivory. Higher lws expression is also exploited by social signalling in orange/red, which emerged after the transition to algivory. Although the relative timing of traits may deviate by different reconstructions and alternative explanations are possible, our results are consistent with sensory bias whereby social signals evolve as a correlated response to natural selection on sensory system properties in other contexts.珊瑚礁鱼类在生态与行为维度兼具极高多样性，同时展现出显著的色彩变异特征。对这类鱼类的视觉色素基因（opsin）表达模式开展研究，可将其视觉基因型与表型（光谱敏感度）关联至特定视觉任务，例如取食策略或同种个体识别。本研究针对雀鲷科（Pomacentridae）所有主要演化支，以及另外5个珊瑚礁鱼类科的代表类群展开分析，结果显示：长波长敏感型（lws）视蛋白在食藻类物种中呈高表达状态，而在浮游动物食性物种中表达量较低甚至完全不表达。此外，lws在具有橙红色体色（反射波长＞520 nm）的物种中同样存在上调表达，且该基因在橙红色体色的食藻类物种中表达量达到峰值。基于典型雀鲷视觉视角构建的视觉模型表明，对长波长的敏感度提升，可增强鱼类检测藻类的红至远红外组分以及橙红色同种个体的能力，这一机制或可支撑社会信号传递。性状状态重建结果显示，在雀鲷科的早期演化历史中，既不存在lws基因表达，也未出现橙红色体色特征。杂食性曾是雀鲷科最主要的取食状态；尽管植食性也曾一度占据演化主导地位，但浮游动物食性从未成为该类群的主流取食模式。长波长敏感度的提升（即lws表达上调）仅与植食性生活方式相关联，从未与浮游动物食性伴随出现。而橙红色体色相关的社会信号传递，则是在类群转向植食性生活之后演化而来，并进一步利用了更高水平的lws表达。尽管不同重建方法可能导致性状演化相对时序存在偏差，且存在其他可行解释，但本研究结果与感官偏倚假说相符——即社会信号的演化是其他情境下感官系统特性受自然选择作用的连带响应。