Erhaia bailong H. Chen, Y. - M. He, H. - Q. Xiang & X. - P. Wu, 2025

Chen, Hui, Xie, Guang-Long, Li, Jun-Xi, Chen, Zhong-Guang, Dai, Yu-Ting, He, Yue-Ming, Xiang, Hong-Quan, Huang, Xiao-Chen & Wu, Xiao-Ping, 2025, Hidden diversity in China's Sky Islands: Three new freshwater snail species of Erhaiidae (Gastropoda, Truncatelloidea) from the Yunnan-Guizhou Plateau, Zoosystematics and Evolution 101 (3), pp. 1359-1368 : 1359-1368

Erhaia bailong H. Chen, Y. - M. He, H. - Q. Xiang & X. - P. Wu sp. nov.

Figs 4 C, D , 5 B

Material examined.

Holotype: • NCUEB 250101 , shell height 2.11 mm (Fig. 4 C ), Bailongtan , Hongtaia District, Yuxi City, Yunnan Province, China, 24.3958°N, 102.6000°E (Fig. 1 ).

Paratypes: • 20 specimens, NCUEH 250102–21 , August 2023, shell height 1.75–2.14 mm, collected by Hong Quan Xiang and Yue Ming He, locality and habitat same as holotype .

Diagnosis.

Shell small, pale greyish, ovoid in shape. Aperture relatively large, sub-ovate, featuring a thick tooth on the columella.

Description.

Shell small, pale greyish, ovoid, consisting of six convex whorls separated by a deep suture. Shell surface exhibits fine irregular growth lines and occasional periostracal ridges. Peristome is continuous and thickened. Without umbilical chink. Apex is typically eroded and obtuse (Fig. 4 C, D ). Aperture is relatively large and sub-ovate, featuring a thick tooth on the columella that extends around the entire body whorl (Fig. 5 B ).

Etymology.

The specific epithet “ bailong ” (from Chinese 白龙, ‘ white dragon’) is treated as a noun in apposition, alluding to a local legend of a white loong (Chinese dragon) inhabiting this spring. The suggested Chinese common name is “ 白龙洱海螺 ” (Báilóng Ěrhǎi Luó).

Biology.

This species inhabits mountain springs and streams, often attaching to fallen leaves on the riverbed, where it occurs in high densities. It avoids deep water and is typically found in slow-moving water at depths of 0–20 cm. Its distribution is recorded at elevations of around 1,800 m.

Remarks.

This species possesses a thickened columellar tooth and is morphologically similar to E. liui (Kang, 1983) , E. shimenensis (Liu, Zhang & Chen, 1982) , E. tangi (Cheng et al., 2007) , and E. jianouensis (Liu & Zhang, 1979) . The present species can be distinguished by its unique combination of a thickened peristome and sub-ovate aperture morphology (Fig. 4 C, D ).

Figures

Figure 1. Distribution of Erhaia species across Asia.

Figure 4. Species of Erhaia. A. Original figure of E. daliensis Davis & Kuo, 1985; B. E. daliensis NCUED 250101; C. E. bailong sp. nov. holotype, NCUEB 250101; D. E. bailong sp. nov. paratype, NCUEB 250102; E. E. guizhouensis sp. nov. holotype, NCUEG 250201; F. E. guizhouensis sp. nov. paratype, NCUEG 250202; G. E. xiaoboqiani sp. nov. holotype, NCUEX 250301; H. E. xiaoboqiani sp. nov. paratype, NCUEX 250302.

Figure 5. SEM photo of the Erhaia species with artificial breakage at the body whorl to expose columella teeth. A. E. daliensis; B. E. bailong sp. nov.; C. E. guizhouensis sp. nov.; D. E. xiaoboqiani sp. nov. Scale bars: 0.5 mm (A – D).