Genomic, ecological, and morphological approaches to investigating species limits: a case study in modern taxonomy from Tropical Eastern Pacific surgeonfishes

A wide variety of species are distinguished by slight color variations. However, molecular analyses have repeatedly demonstrated that coloration does not always correspond to distinct evolutionary histories between closely related groups, suggesting that this trait is labile and can be misleading for species identification. In the present study, we analyze the evolutionary history of sister species of Prionurus surgeonfishes in the Tropical Eastern Pacific (TEP), which are distinguished by the presence or absence of dark spots on their body. We examined the species limits in this system using comparative specimen-based approaches, a mitochondrial gene (COI), more than 800 nuclear loci (Ultraconserved Elements), and abiotic niche comparisons. The results indicate there is a complete overlap of meristic counts and morphometric measurements between the two species. Further, we detected multiple individuals with intermediate spotting patterns suggesting that coloration is not diagnostic. Mi...

多种物种可通过细微的颜色差异加以区分。然而，分子分析反复表明，在亲缘关系较近的类群间，体色并不总是与独特的进化历史相对应，这表明该性状具有不稳定性，可能会对物种鉴定产生误导。本研究分析了热带东太平洋（Tropical Eastern Pacific, TEP）地区锯尾鲷属（Prionurus）外科医生鱼姐妹种的进化历史，这些物种的区别在于身体上是否存在黑斑。我们采用基于标本的比较方法、线粒体基因（细胞色素c氧化酶亚基I，COI）、800多个核基因座（超保守元件，Ultraconserved Elements）以及非生物生态位比较，对该系统中的物种界限进行了研究。结果显示，两个物种的可数性状计数和形态测量数据完全重叠。此外，我们发现多个个体具有中间型黑斑模式，这表明体色并非诊断性特征。此...