Three new species of Valvatidae, Planorbidae, and Lymnaeidae (Mollusca, Gastropoda) from Lake Bitahai, Yunnan Plateau, China

Three new species of freshwater snails are described from Lake Bitahai, a small plateau lake located in the high altitude region of northwestern Yunnan, China: <i>Valvata bitaensis</i> Zhang, <b>sp. nov.</b>, <i>Gyraulus semskyinyizla</i> Zhang, <b>sp. nov.</b>, and <i>Radix shangrila</i> Zhang, <b>sp. nov.</b> These new species can be distinguished from their congeners by morphology and molecular phylogenetic analyses. <i>Valvata bitaensis</i> Zhang, <b>sp. nov.</b> has an aperture that is always detached from the body whorl, while its shell is sometimes uncoiled. <i>Gyraulus semskyinyizla</i> Zhang, <b>sp. nov.</b> can be distinguished from its sister species <i>Gyraulus chinensis</i> by its rough periostracum and mantle roof with dense fine black dots. <i>Radix shangrila</i> Zhang, <b>sp. nov.</b> can be distinguished from its congeners by the morphology of its columellar lip and mantle pigments. Following the discovery of these three new freshwater snail species, Lake Bitahai now harbours five endemic species, highlighting its significant value for biodiversity conservation.