Dalipaludina Zhang, 2023

Zhang, Le-Jia, Du, Li-Na & von Rintelen, Thomas, 2023, A new genus of river snails, Dalipaludina (Gastropoda, Viviparidae), endemic to the Yunnan Plateau of SW China, Zoosystematics and Evolution 99 (2), pp. 285-297 : 285

Dalipaludina Zhang gen. nov.

Type species.

Paludina delavayana Heude, 1889.

Etymology.

“Dali” refers to the ancient Dali Kingdom (大理国) mostly situated in modern Yunnan, China; “paludina” refers the assignment to Viviparidae . The recommended Chinese name is “理田螺”.

Diagnosis.

Shell large, thin but solid; apex acute; teleoconch whorls with strong keel at suture, above suture relatively smooth or with several weak spiral threads or strong spiral cords, many thin and weak spiral threads on base; umbilicus narrow, sometimes bordered by a keel; exterior surface of operculum rather smooth, inner opercular region relatively small, nuclear region of operculum smooth, sometimes with small grains; outer marginal tooth with 9 to 11 small sharp cusps.

Comparative remarks.

Dalipaludina gen. nov. resembles Cipangopaludina (widely distributed in East Asia), Ussuripaludina Zatravkin & Bogatov, 1987 (endemic to Far East), Heterogen Annandale, 1921 (endemic to Japan and Korea), and Torotaia Haas, 1939 (endemic to Philippines, Sulawesi and New Guinea). It differs from Cipangopaludina , Ussuripaludina , Heterogen and Torotaia by having one strong keel at the suture, a shell base with many thin and weak spiral threads, a narrow umbilicus sometimes bordered by a keel, and operculum characters. The molecular phylogeny supports that Dalipaludina is distinct from Cipangopaludina , Ussuripaludina , Heterogen and Torotaia . The location of the testis in male Dalipaludina specimens in the mantle cavity supports the classification of this genus in the subfamily Bellamyinae . There are four known species of Dalipaludina .

Distribution.

This genus is endemic to the lakes or ponds in northwest to northeast Yunnan, China.