Shupaludina magnaciana ( Heude, 1889 ), 2025

Shupaludina magnaciana ( Heude, 1889) comb. nov.

Figs 2 View Figure 2 , 3 A View Figure 3 , 4 A, B View Figure 4 , 5 A View Figure 5

Paludina magnaciana Heude, 1889: 48 (Valle Tchong-King).

Paludina magnaciana - Heude, 1890: 177 (flumine K’iu (渠 )).

Syntype.

ASIZB FG 492559 –60, MCZ Mala 167345 , Kiu-h , Se tch (= Qu County [渠县], Dazhou City [达州市], Sichuan Province [四川省]), leg. P. Magnac .

New materials.

n = 100. NCUMB 19001 –010, Baimuhe River [柏木河], Yunqiao Wetland [云桥湿地], Pidu District [郫都区], Chengdu City, Sichuan Province, China, 30.87573°N, 103.88175°E, leg. Zhong-Guang Chen, November 2019 GoogleMaps ; NCUMB 19011 –60, ZMNH 8009 –8028, IHB 0202506001 –5, SAFS 250001 –5 Yangliuhe River [杨柳河], Wenjiang District [温江区], Chengdu City [成都市], Sichuan Province, China, 30.81937°N, 103.71643°E, leg. Zhong-Guang Chen, November 2019 GoogleMaps ; NCUMB 19061 –70, Mengyanghe River [濛阳河], Mengyang Town [濛阳镇], Pengzhou City [彭州市], Chengdu City [成都市], Sichuan Province, China, 30.95389°N, 104.11625°E, leg. Zhong-Guang Chen, November 2019 GoogleMaps .

Diagnosis.

Early teleoconch with dense spiral lines. Teleoconch with a weak but distinct keel at suture, above and below suture with several weak and indistinct keels. Aperture ovate. Lateral tooth with a large, broad, and blunt central denticle and four small and sharp cusps on both sides; inner marginal tooth with a large, broad, and blunt central denticle and four small and sharp cusps on both sides; outer marginal tooth with 15–16 long and very sharp cusps.

Description.

Shell conical, dextral, small to medium-sized ( SH 23.8–40.4 mm), relatively thick, solid, opaque, glossy, with 6.0–7.0 whorls in adults. Whorls inflated. Suture rather deep. Early teleoconch with dense spiral lines invisible to the naked eye, apex blunt and low. Teleoconch with a weak but distinct keel at suture, above and below suture with several weaker and indistinct keels, without hairs, with dense growth lines. Aperture waved, ovate, oblique, more than half of shell in height. Inner shell surface orange to white. Outer lip black and 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 yellowish-green to reddish-brown, apex region darker.

Operculum much smaller than aperture ( OH / AH = 0.72–0.83), 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 four small and sharp cusps on both sides; inner marginal tooth with a large, broad, and blunt central denticle and four small and sharp cusps on both sides; outer marginal tooth with 15–16 long and very sharp cusps.

Measurements.

Syntype: SH 25.1–30.9 mm, SW 18.9–23.7 mm; AH 14.0– 17.8 mm, AW 10.3–12.4 mm; SW / SH = 0.75–0.77, AW / AH = 0.70–0.74, AH / SH = 0.56–0.57. New materials: SH 23.8–40.4 mm, SW 20.2–29.6 mm; AH 15.8–22.1 mm, AW 11.6–16.7 mm; OH 12.9–16.1, OW 8.3–10.8; SW / SH = 0.72–0.85, AW / AH = 0.71–0.80, AH / SH = 0.55–0.66, OH / AH = 0.72–0.83.

Vernacular name.

马氏蜀田螺 (mǎ shì shǔ tián luó).

Distribution and ecology.

Currently only found in the tributaries of the Minjiang River and the Tuojiang River in northwestern Chengdu (Fig. 6 View Figure 6 ). Maybe distributed in the Qujiang River Basin from eastern Sichuan to northern Chongqing. Living in the pebble-bottom sections of the cold and flowing tributaries with seasonal floods in sympatry with Hua bailleti (Bavay & Dautzenberg, 1910) , Lithoglyphopsis spp. , and Tricula spp. (Fig. 6 View Figure 6 ). No living animals were found in the main streams or the muddy or still-water sections of the tributaries.

Remarks.

Heude (1889) recorded the type locality of this species as “ Valle Tchong-King ( Se-tchouan orientalis) ”. Later, Heude (1890) further recorded the type locality as “ in flumine K’iu (渠), in Yang-tze prope Tchong-K’ing influente ”. However, upon examination of the type specimen, it was found that the type locality indicated on the initial handwritten label was Kiu-h (= Kiu [渠] - hien [县], = Qu County [渠县] of Dazhou City) (Fig. 7 View Figure 7 ). Qu County is located in the mountainous area of northeastern Sichuan, hundreds of kilometers away from Chongqing ( Tchong-King), with significant environmental and aquatic animal fauna differences ( Guo et al. 2021; Guo 2022). In order to find out the true type locality and distribution, we conducted a survey in Chongqing and Sichuan. Finally, we only found specimens that fit the type specimens around Chengdu (Fig. 6 View Figure 6 ). We cannot determine whether the species became extinct in the Qujiang River Basin or if the type locality was incorrect.