The Lower Mekong Basin (LMB) is a key biodiversity hotspot. To facilitate conservation and management, we examine mollusc biodiversity patterns and distribution along LMB’s longitudinal gradients, identify environmental drivers, and discuss the importance of these drivers to management. Cluster analysis, redundancy analysis (RDA), and variation partitioning were conducted using mollusc data collected from 63 sampling sites. Results indicated that species diversity is dominated by gastropods (61%) and bivalves (39%) and feeding trait diversity by scrapers (52%) and filter-collectors (37%). Only 48 species (49%) out of 98 taxa have been assessed by the International Union for Conservation of Nature (IUCN) including a growing number of invasive species. The lack of complete, up-to-date information highlights the need for more research on both native and alien species. Cluster analysis revealed a clear mollusc biodiversity structure along the LMB’s longitudinal segments. Diversity was lowest in upstream tributaries, increased in upstream main channels, and was highest in downstream channels and the Mekong delta, the exception being the observed high gastropod abundance in Chi-Mun river mouth and Luang Prabang areas. The RDA and variation partitioning demonstrated that combined physical–chemical and climatic conditions are the key drivers of biodiversity patterns. Given the potential spread of invasive alien species and increasing anthropogenic impacts, further ecological research, regular monitoring, and adaptive management are needed to sustain mollusc biodiversity and associated ecosystem services, which contribute to food security, nutrition, and livelihoods in the LMB.

中文翻译：

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湄公河软体动物生物多样性模式：识别全球重要生物多样性和地方性地区的新威胁及其对管理和生计的重要性

湄公河下游盆地 (LMB) 是一个重要的生物多样性热点。为了促进保护和管理，我们研究了软体动物生物多样性模式和沿 LMB 纵向梯度的分布，确定了环境驱动因素，并讨论了这些驱动因素对管理的重要性。使用从 63 个采样点收集的软体动物数据进行聚类分析、冗余分析 (RDA) 和变异划分。结果表明，物种多样性以腹足类 (61%) 和双壳类 (39%) 为主，捕食性状多样性以刮刀 (52%) 和过滤收集器 (37%) 为主。国际自然保护联盟 (IUCN) 对 98 个分类群中只有 48 个物种 (49%) 进行了评估，其中包括越来越多的入侵物种。缺乏完整，最新信息突出表明需要对本地和外来物种进行更多研究。聚类分析揭示了沿 LMB 纵向段的清晰的软体动物生物多样性结构。上游支流多样性最低，上游主要河道增加，下游河道和湄公河三角洲最高，但在赤门河口和琅勃拉邦地区观察到的腹足动物丰度高。RDA 和变异划分表明，物理-化学和气候条件的组合是生物多样性模式的关键驱动因素。鉴于外来入侵物种的潜在传播和日益增加的人为影响，需要进一步的生态研究、定期监测和适应性管理，以维持软体动物的生物多样性和相关的生态系统服务，