A new freshwater snail genus of Squamapicidae (Gastropoda, Truncatelloidea) with a novel posterior respiratory canal unveils an unexpected morphological innovation

Highly ornamented protoconchs and a developed posterior canal are exceptionally rare and unique shell characteristics in strict freshwater gastropods. This study combines morphological and molecular phylogenetic approaches to describe a new genus and species within the Squamapicidae family that possesses the characteristic of a highly ornamented protoconch: Canglangia heyuemingi H. Zheng, H.-Q. Xiang, L.-J. Zhang & X.-P. Wu, gen. et sp. nov . Through the observation and cultivation of three species of freshwater snails with highly ornamented protoconchs from Yunnan, it was found that the formation and function of the highly ornamented protoconch vary across different species. The role of the posterior canal is discussed by examining the habitat of C. heyuemingi gen. et sp. nov .