Two new genera and species of river snails from the upper Changjiang River Basin in China (Gastropoda, Viviparidae)

Two new genera, Shupaludina Z.-G. Chen, Y.-T. Dai, H. Chen & X.-P. Wu, gen. nov., and Bapaludina Z.-G. Chen & Y.-S. Guo, gen. nov., and two new species, Shupaludina luzhouensis Z.-G. Chen & Y.-S. Guo, gen. et sp. nov., and Bapaludina dazhouensis Z.-G. Chen & Y.-S. Guo, gen. et sp. nov., of river snails are described from the upper Changjiang River Basin in China based on comparative morphology and molecular phylogeny. The two new genera have similar shell morphology and can be distinguished from other genera of the subfamily by common features such as a small- to medium-sized shell, a blunt apex, inflated whorls, the inner lip of the aperture folded and tightly overlapping the columellar margin, completely covering the umbilicus and forming with growth a crescent-shaped fortification (even in juvenile specimens), and an operculum much smaller than the aperture. They can be distinguished from each other by the presence or absence of keels on the teleoconch, differences in the size of the crescent-shaped fortification, differences in the size of the operculum, and differences in the radula. The discovery increases the known diversity of river snails in the upper Changjiang River.