Abstract：
Dam construction in riverine ecosystems has fragmented natural aquatic habitats and has altered environmental conditions. As a result, damming has been demonstrated to threaten aquatic biodiversity by reducing species distribution ranges and hindering gene exchange, leading to the inability to adapt to environmental changes. Knowledge of the contemporary genetic diversity and genetic structure of fish populations that are separated by dams is vital to developing effective conservation strategies, particularly for endangered fish species. We chose the Lianjiang River, a tributary of the Pearl River, as a case study to assess the effects of dams on the genetic diversity and genetic structure of an endangered fish species, Hemibagrus guttatus, using whole-genome resequencing data from 63 fish samples. The results indicated low levels of genetic diversity, high levels of inbreeding and decreasing trend of effective population size in fragmented H. guttatus populations. In addition, there were significant genetic structure and genetic differentiation among populations, suggesting that the dams might have affected H. guttatus populations. Our findings may benefit management and conservation practices for this endangered species that is currently suffering from the effects of dam construction.
摘要：
河流生态系统中的大坝建设使自然水生栖息地支离破碎，并改变了环境条件。因此,已经证明，筑坝通过减少物种分布范围和阻碍基因交换来威胁水生生物多样性，导致无法适应环境变化。了解被水坝隔开的鱼类种群的当代遗传多样性和遗传结构对于制定有效的保护策略至关重要，特别是濒危鱼类。我们选择了连江，珠江的支流,作为评估水坝对濒危鱼类的遗传多样性和遗传结构影响的案例研究，Hemibagrusguttatus,使用来自63个鱼类样本的全基因组重测序数据。结果表明，遗传多样性水平较低，在零散的H.guttatus种群中，高水平的近亲繁殖和有效种群大小的减少趋势。此外,种群间存在显著的遗传结构和遗传分化,这表明水坝可能影响了口蹄疫的种群。我们的发现可能有利于这种目前正在遭受大坝建设影响的濒危物种的管理和保护实践。
