Aquatic invasive species decrease biodiversity and disrupt economic systems worldwide. Apple snails (Ampullaridae) from the genus Pomacea are globally invasive species that are highly damaging to aquaculture and aquatic ecosystems. Pomacea maculata was introduced to Louisiana in the early 2000s and rapidly spread throughout the southern half of the state, where invasive populations now threaten valuable aquaculture economies and a large area of aquatic ecosystems that sustain biodiversity important to commercial and recreational fisheries. Despite these risks, little work has been dedicated to understanding how apple snails disperse through invaded areas in Louisiana. To shed light on potential dispersal dynamics, we assessed population genetic structure of P. maculata in Louisiana at multiple spatial scales using microsatellites of snails collected from seven sampling locations. Overall, genetic diversity was relatively high across all sampling locations. Significant genetic structure was observed among sampling sites, indicating Barataria Preserve and the four sampling locations within Terrebonne Basin as distinct populations. Genetic distances were smallest among the four sampling locations within Terrebonne Basin. These findings suggest that dispersal within hydrologic units is higher than between units, meaning that apple snails may primarily move through systems through passive downstream dispersal. However, geographically distant populations also showed evidence of genetic mixing, pointing toward human-aided long-distance dispersal events. Regular dispersal of apple snails within and among hydrologic units highlights the risk of invasions in highly interconnected aquatic systems where dispersal rates may be especially high due to human modifications.

水生入侵物种减少了生物多样性并扰乱了全世界的经济系统。苹果螺（Ampullaridae）属于福寿螺属， 是全球入侵物种，对水产养殖和水生生态系统造成严重破坏。福寿螺于 2000 年代初被引入路易斯安那州，并迅速蔓延到该州的南半部，那里的入侵种群现在威胁着宝贵的水产养殖经济和大面积的水生生态系统，而这些生态系统维持着对商业和休闲渔业至关重要的生物多样性。尽管存在这些风险，但很少有人致力于了解苹果螺如何在路易斯安那州的入侵地区扩散。为了揭示潜在的扩散动态，我们使用从七个采样点收集的蜗牛微卫星在多个空间尺度上评估了路易斯安那州斑螺的种群遗传结构。总体而言，所有采样地点的遗传多样性都相对较高。在采样点之间观察到显着的遗传结构，表明巴拉塔里亚保护区和泰雷博讷盆地内的四个采样点是不同的种群。特雷博讷盆地内的四个采样点中遗传距离最小。这些发现表明，水文单元内的扩散高于单元之间的扩散，这意味着苹果螺可能主要通过被动下游扩散在系统中移动。然而，地理上遥远的种群也显示出基因混合的证据，表明人类辅助的长距离扩散事件。苹果螺在水文单位内部和之间的定期扩散凸显了高度互联的水生系统入侵的风险，在这些系统中，由于人类的改变，扩散率可能特别高。