Exploring freshwater snail diversity and community structure in china's largest lake using eDNA technology

Freshwater snails are a crucial benthic animal group that plays a pivotal role in algae regulation and ecosystems while serving as intermediate hosts for certain parasites. Environmental DNA (eDNA) technology offers numerous advantages for biodiversity assessment. However, the utilization of eDNA techniques for freshwater snail monitoring remains limited. In this study, we screened primers for assessing freshwater snail diversity using eDNA technology and constructed a comprehensive database for Poyang Lake. Using eDNA technology, a total of 21 species of snails were detected in Poyang Lake, while traditional methods detected only 11 species. Notably, all species collected by traditional methods were also detected by eDNA technology. Additionally, environmental DNA methods detected the invasive snail Pomacea canaliculata, while traditional methods did not. In this study, eleven intermediate host snail species for parasitic disease were identified using eDNA methods, while six were detected through traditional sampling techniques. The eDNA metabarcoding analysis showed that the alpha and beta diversity levels of snails in Poyang Lake did not vary significantly, indicating that results obtained by eDNA sampling are not influenced by the season in which samples were collected. The correlation analysis between the community structure of snails and environmental factors in Poyang Lake revealed significant impacts of total nitrogen, chlorophyll a, water depth, and water temperature on the snail community structure. These results confirm that eDNA technology can be exploited to monitor freshwater snail biodiversity.