Chinese researchers find freshwater snail species missing for nearly a century

The extant shell specimens of Yawangia leei (A–O), along with the specimens of shells found in Quaternary sediment layers (P–T). [Photo provided to chinadaily.com.cn]

Chinese researchers have rediscovered a freshwater snail species thought to have been extinct for nearly a century in Guilin, Guangxi Zhuang autonomous region.

A research team from the Kunming Institute of Zoology under the Chinese Academy of Sciences has confirmed through detailed morphological and phylogenetic analyses that the species belongs to the genus Yawangia leei. The genus is closely related to Dalipaludina, a group of snails endemic to the high-altitude still-water environments of Yunnan province.

Zhang Lejia, the study's first author and an assistant researcher at the institute, said Yawangia leei was long known only from fossilized shells found in Quaternary deposits in caves in Guilin. The species had been considered extinct, with no reports since its initial description nearly a century ago.

Late last year, the team discovered a very small living population of the snail in a river near downtown Guilin. Zhang said the shells of the living specimens match perfectly with the fossil type specimens, including all morphological variations previously found in the species' cave type locality.

The findings were published on Oct 23 in the international journal Zoologica Scripta.