Diversity in an ancient lake: taxonomic and phylogenetic insights from eight new freshwater snail species (Triculinae: Pomatiopsidae) of Lake Fuxian, Southwest China

Abstract Lake Fuxian, an ancient lake in Yunnan Province, Southwest China, harbours many endemic species, yet its biodiversity remains poorly characterized. Through comprehensive surveys of freshwater snails along its shores, we documented remarkable biodiversity within the subfamily Triculinae. In this study, we describe eight new species, including four new species of the genus Kunmingia and four new species representing a new genus, Farshore He, Chen, Xiang and Zhang gen. nov. Phylogenetic analyses of partial mitochondrial genes (COI and 16S ribosomal DNA) and nuclear markers (18S and 28S ribosomal DNA) provided robust genetic evidence supporting the distinctiveness of these newly described taxa. The time-calibrated phylogeny of the endemic freshwater snails shows that Kunmingia clade and Farshore clade diverged in the late Miocene, suggesting that the geological history of Lake Fuxian might be older than previously estimated. These findings highlight the importance of Lake Fuxian as a hotspot of freshwater snail diversity and a unique system for studying evolutionary processes in ancient lakes.