Gabbia nana Zhang & Shu & Song & Naing & Oo & Chen 2025, comb. nov.

Gabbia nana (Annandale 1918) comb. nov. Hydrobioides nana Annandale, 1918: 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. e), 20°28'02.6"N, 96°55'58.1"E, 5 Jul. 2024, Le-Jia Zhang leg., KIZ.2400065 –2400075. Description. Shell (Fig. 9) small for the family (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, 4 C) 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) 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). 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.