Gabbia nana ( Annandale 1918 ), 2025

Zhang, Le-Jia, Shu, Shu-Sen, Song, Xin-Yuan, Naing, Nay Htet, Oo, Thaung Naing & Chen, Xiao-Yong, 2025, A revision of Bithyniidae (Mollusca, Gastropoda) from the Inle Lake Basin, Myanmar, Zoosystematics and Evolution 101 (2), pp. 643-660 : 643-660

publication ID	https://doi.org/10.3897/zse.101.143936
publication LSID	lsid:zoobank.org:pub:C0F8018F-646D-491E-A749-715896CBF713
DOI	https://doi.org/10.5281/zenodo.15079025
persistent identifier	https://treatment.plazi.org/id/C3036AF7-99B8-56F9-800E-C234D9F65FC8
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Gabbia nana ( Annandale 1918 )
status	comb. nov.

Treatment

Gabbia nana ( Annandale 1918) comb. nov.

Hydrobioides nana Annandale, 1918 View in CoL : pl. 14, fig. 3 ( Myanmar, Shan State, NW shore of Inle Lake, Fort Stedman, now Maing Thauk).

Diagnosis.

Shell small, transparent white to pale yellow, high spiral whorls, inflated body whorl.

Material examined.

• 10 specimens (preserved in ethanol), Shan State, Taunggyi District, Nampan , water in rice field (Fig. 1 B View Figure 1 . e), 20°28'02.6"N, 96°55'58.1"E, 5 Jul. 2024, Le-Jia Zhang leg., KIZ.2400065 –2400075 GoogleMaps .

Description.

Shell (Fig. 9 View Figure 9 ) small for the family (Table 1 View Table 1 ), thin but solid, subglobose, transparent white to pale yellow, with four to 4.5 whorls at adulthood; teleoconch relatively high, smooth, without shoulder, body whorl inflated; aperture ovate, lip slightly thickened, always more than half of shell in height; umbilicus covered by inner lip or with narrow slit.

Operculum (Figs 9 A, F View Figure 9 , 4 C View Figure 4 ) calcium, ovate, thin, slightly bigger than aperture, transparent grey; exterior surface smooth, nucleus close to inner opercular margin; interior surface with weak concentric growth lines and small grains on inner opercular region.

No fresh male specimen discovered.

Radula (Fig. 10 View Figure 10 ) taenioglossate; central tooth upper margin with one long triangle central cusp and three small sharp cusps on either side, lateral margin each with three small sharp cusps; lateral tooth with one long triangle central cusp and four small sharp cusps; inner marginal tooth with 16 to 17 small cusps; outer marginal tooth with nine small cusps.

Remarks.

This species is assigned to Gabbia based on its morphology of a small globose shell with an inflated body whorl and its close relationship with Gabbia pygmaea in the molecular phylogeny (Fig. 2 View Figure 2 ). It cannot be assigned to Hydrobioides since this species lacks an outward extended outer lip. It can be distinguished from Gabbia pygmaea (Preston, 1908) (type locality: Myanmar, Thayet) based on its higher spiral whorls and white to pale yellow shell.

Habitat and distribution.

Only known from the wetlands and small creeks in the Inle Lake basin.