Shupaludina luzhouensis Z. - G. Chen & Y. - S. Guo 2025, sp. nov.

Shupaludina luzhouensis Z.-G. Chen & Y.-S. Guo sp. nov. Figs 3 B, 4 C, D, 8 Holotype. NCUMB 25001, Huagaoxi River [画稿溪], Shuiwei Town [水尾镇], Xuyong County [叙永县], Luzhou City [泸州市], Sichuan Province, China, 28.25156°N, 105.63852°E, leg. Zhong-Guang Chen, June 2025. Paratypes. n = 15. NCUMB 25002 –014, ZMNH 8029 –8030, other information same as holotype. Diagnosis. Early teleoconch almost smooth, with very weak and sparse spiral lines. Teleoconch without a weak but distinct keel at suture, but with several weak and indistinct keels. Aperture ovate, elongated. Lateral tooth with a large, broad, and blunt central denticle and five small and sharp cusps on both sides; inner marginal tooth with a large, broad, and blunt central denticle and five small and sharp cusps on both sides; outer marginal tooth with 19–22 long and very sharp cusps. Description. Shell conical, dextral, small to medium-sized (SH 20.3–40.4 mm), relatively thick, solid, opaque, glossy, with 5.5–6.0 whorls in adults. Whorls inflated. Suture rather deep. Early teleoconch almost smooth, with very weak and sparse spiral lines, apex blunt and low. Teleoconch without a weak but distinct keel at suture, but with several weak and indistinct keels, without hairs, with dense growth lines. Aperture waved, ovate, elongated, oblique, more than half of shell in height. Inner shell surface orange to white. Outer lip brown, not thickened, inner lip of the aperture is folded and tightly overlapping on the columellar margin, completely covering the umbilicus and forming with growth a crescent-shaped fortification, even in juvenile specimens. Shell multicolored, teleoconch brown, apex region darker. Operculum much smaller than aperture (OH / AH = 0.77–0.80), corneous, ovate, rather thick, dark brown, exterior surface of operculum rough, inner surface of operculum with a smooth outer ring and a rough inner ring, the nuclear region with shiny grains. Radular central tooth with a relatively sharp central denticle and six small and sharp cusps on both sides; lateral tooth with a large, broad, and blunt central denticle and five small and sharp cusps on both sides; inner marginal tooth with a large, broad, and blunt central denticle and five small and sharp cusps on both sides; outer marginal tooth with 19–22 long and very sharp cusps. Measurements. Holotype: SH 30.8 mm, SW 23.5 mm; AH 19.3 mm, AW 14.0 mm; OH 15.1, OW 10.5; SW / SH = 0.76, AW / AH = 0.73, AH / SH = 0.63, OH / AH = 0.78. Paratypes: SH 20.3–32.3 mm, SW 17.6–23.6 mm; AH 14.9–20.1 mm, AW 9.6–14.2 mm; OH 11.5–15.8, OW 7.4–10.9; SW / SH = 0.73–0.87, AW / AH = 0.64–0.73, AH / SH = 0.61–0.73, OH / AH = 0.77–0.80. Etymology. The species is named after its type locality, Luzhou. Vernacular name. 泸州蜀田螺 (lú zhōu shǔ tián luó). Distribution and ecology. Known from the Huagaoxi River only, a tributary of the Yongninghe River in southern Luzhou (Fig. 6). Living in the pebble-bottom sections of the cold and flowing tributaries with seasonal floods in sympatry with Hua sp., Lithoglyphopsis sp., and Tricula sp. (Fig. 6). No living animals were found in the main streams or the muddy or still-water sections of the tributaries. Remarks. The new species can be easily distinguished from Shupaludina magnaciana comb. nov. by absence of a weak but distinct keel at suture on teleoconch (vs. presence), early teleoconch almost smooth, with very weak and sparse spiral lines (vs. with distinct and dense spiral lines), a more narrow and elongated aperture, a thinner inner lip, and more outer marginal tooth (19–22 vs. 15–16). The two species can also be distinguished by their distant and isolated distributions.