In river ecosystems, spatial complexity as well as anthropogenic factors operating at different temporal and spatial scales are shaping demography, connectivity and population genetic structure of species inhabiting these habitats. Chilina dombeiana is a freshwater gastropod with direct development (absence of a free larval phase) that inhabits the Biobío river basin in Chile (36°S). No studies have yet evaluated the spatial patterns of the genetic diversity of this species and the potential factors that influence these patterns. Consequently, in this study, we analyzed the population genetics of C. dombeiana based on 15 locations along the Biobío river. Eight microsatellite loci were genotyped. Also, at each sampling site, 40 environmental parameters were recorded to characterize them. Results showed that C. dombeiana has low genetic variability with high population structure. In addition, we detected signs of historical decreases in effective population sizes, unidirectional gene flow (upstream to downstream) and contemporary demographic bottleneck. Spatial subdivisions in populations showed a pattern of isolation by distance. The redundancy analysis and variance partitioning showed that spatial components and dissolved oxygen could explain 28% of the interpopulation genetic variation, while the Random Forest analysis identified significant effects of dissolved oxygen, nitrite and total coliforms on the genetic variability of populations (22%). Although C. dombeiana is widely distributed in Chilean rivers, its low dispersal and specific habitat requirements make this species very sensitive to the severe increase in anthropogenic disturbances affecting river ecosystems in recent decades. Long-term monitoring of genetic population conditions and environmental parameters are needed to implement robust management and conservation policies.

在河流生态系统中，空间复杂性以及在不同时空尺度上运行的人为因素正在影响居住在这些栖息地的物种的人口统计，连通性和种群遗传结构。奇利纳·多贝纳奇虫（Chilina dombeiana）是一种直接发育（没有游离幼虫期）的淡水腹足类动物，栖息于智利比奥比奥河流域（36°S）。尚无研究评估该物种遗传多样性的空间格局以及影响这些格局的潜在因素。因此，在这项研究中，我们分析了C的种群遗传学。多贝那根据比奥比奥河上的15个地点。对八个微卫星基因座进行了基因分型。另外，在每个采样点，记录了40个环境参数以表征它们。结果表明，C。多贝那遗传变异低，种群结构高。此外，我们发现了有效种群规模，单向基因流（从上游到下游）和当代人口瓶颈的历史下降迹象。人口中的空间细分显示了按距离隔离的模式。冗余分析和方差划分表明，空间成分和溶解氧可以解释种群间遗传变异的28％，而随机森林分析则确定了溶解氧，亚硝酸盐和大肠菌群对种群遗传变异的显着影响（22％）。虽然Ç。多贝那智利河流域广泛分布，其低扩散性和特定的栖息地要求使该物种对近几十年来影响河流生态系统的人为干扰的急剧增加非常敏感。需要对遗传种群状况和环境参数进行长期监测，以实施强有力的管理和保护政策。