Species delimitation in endangered groundwater salamanders: implications for aquifer management and biodiversity conservation

Groundwater-dependent species are among the least-known components of global biodiversity, as well as some of the most vulnerable because of rapid groundwater depletion at regional and global scales. The karstic Edwards–Trinity aquifer system of west-central Texas is one of the most species-rich groundwater systems in the world, represented by dozens of endemic groundwater-obligate species with narrow, naturally fragmented distributions. Here, we examine how geomorphological and hydrogeological processes have driven population divergence and speciation in a radiation of salamanders (Eurycea) endemic to the Edwards–Trinity system using phylogenetic and population genetic analysis of genome-wide DNA sequence data. Results revealed complex patterns of isolation and reconnection driven by surface and subsurface hydrology, resulting in both adaptive and non-adaptive population divergence and speciation. Our results uncover new cryptic species diversity and refine the borders of several threa...依赖地下水的物种是全球生物多样性中鲜为人知的类群之一，同时也是受区域及全球尺度内地下水快速枯竭影响最严重的脆弱类群之一。美国德克萨斯州中西部的喀斯特型爱德华兹-特里尼蒂含水层系统（karstic Edwards–Trinity aquifer system）是全球物种多样性最丰富的地下水生态系统之一，栖息着数十种分布范围狭窄且天然碎片化的专性地下水特有物种。本研究基于全基因组DNA序列数据的系统发育与种群遗传学分析，探讨了地貌学与水文地质过程如何驱动爱德华兹-特里尼蒂含水层系统特有的无肺螈属（Eurycea）辐射演化类群的种群分化与物种形成。研究结果揭示了由地表与地下水文过程驱动的复杂隔离-再连接格局，该格局同时引发了适应性与非适应性的种群分化及物种形成事件。本研究揭示了新的隐存物种多样性，并对若干受威胁类群的分布边界进行了修正……