Tettamanti Valerio, Marshall N Justin, Cheney Karen L, Cortesi Fabio
Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.
School of the Environment, The University of Queensland, Brisbane, Queensland, Australia.
Mol Ecol. 2025 Mar;34(6):e17680. doi: 10.1111/mec.17680. Epub 2025 Feb 5.
Damselfishes (Pomacentridae) are widespread and highly abundant on tropical coral reefs. They exhibit diverse body colouration within and between the ~250 species and across ontogenetic stages. In addition to human-visible colours (i.e., 400-700 nm), most adult damselfishes reflect ultraviolet (UV, 300-400 nm) colour patches. UV sensitivity and UV colour signals are essential for feeding and form the basis for a secret communication channel invisible to the many UV-blind predatory fish on the reef; however, how these traits develop across ontogenetic stages and their distribution across the damselfish family is poorly characterised. Here, we used UV photography, phylogenetic reconstructions of opsin genes, and differential gene expression analysis (DGE) of retinal samples to investigate the development of UV vision and colour patterns in three ontogenetic stages (pre-settlement larval, juvenile, and adult) of 11 damselfish species. Using DGE, we found similar gene expression between juveniles and adults, which strongly differed from larvae. All species and all stages expressed at least one UV-sensitive sws1 opsin gene. However, UV body colour patterns only started to appear at the juvenile stage. Moreover, Pomacentrus species displayed highly complex UV body patterns that were correlated with the expression of two sws1 copies. This could mean that some damselfishes can discriminate colours that change only in their UV component. We demonstrate dramatic shifts in both UV sensitivity and UV colouration across the development stages of damselfish while highlighting the importance of considering ontogeny when studying the coevolution of visual systems and colour signals.
雀鲷科鱼类广泛分布于热带珊瑚礁，数量极为丰富。在约250个物种内部及之间，以及在个体发育阶段中，它们呈现出多样的体色。除了人类可见的颜色（即400 - 700纳米）外，大多数成年雀鲷科鱼类还反射紫外线（UV，300 - 400纳米）色斑。紫外线敏感性和紫外线颜色信号对于觅食至关重要，并且构成了珊瑚礁上许多对紫外线不敏感的掠食性鱼类所看不见的秘密通信渠道的基础；然而，这些特征在个体发育阶段如何发展以及它们在雀鲷科中的分布情况却鲜为人知。在这里，我们使用紫外线摄影、视蛋白基因的系统发育重建以及视网膜样本的差异基因表达分析（DGE），来研究11种雀鲷科鱼类在三个个体发育阶段（定居前幼虫、幼鱼和成鱼）中紫外线视觉和颜色模式的发展。通过DGE，我们发现幼鱼和成鱼之间的基因表达相似，这与幼虫有很大不同。所有物种和所有阶段都至少表达一种对紫外线敏感的sws1视蛋白基因。然而，紫外线体色模式直到幼鱼阶段才开始出现。此外，雀鲷属物种呈现出高度复杂的紫外线体色模式，这与两个sws1拷贝的表达相关。这可能意味着一些雀鲷科鱼类能够辨别仅在紫外线成分上发生变化的颜色。我们展示了雀鲷科鱼类在发育阶段中紫外线敏感性和紫外线颜色的巨大变化，同时强调了在研究视觉系统和颜色信号的协同进化时考虑个体发育的重要性。
