New species of land snails (Mollusca: Gastropoda: Caenogastropoda and Pulmonata) of the Mekong Delta Limestone Hills (Cambodia, Vietnam)

Abstract

Twenty-two new species of land snails are described from limestone hills on the west flank of the Mekong river delta, in Cambodia and Vietnam. The species belong to the families Assimineidae, Cyclophoridae, Diplommatinidae, Ariophantidae, Helicarionidae, Streptaxidae and Vertiginidae.

Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda)

“…11; Fig. 7E) agree well with the drawing by Vermeulen et al (2019b). This species tends to have a much smaller shell size and be less abundant than the syntopic congener H. cambodjense Benthem Jutting, 1962. The specimens from locality no.…”

Two land snail species of the Mekong Delta limestone hills (Cambodia, Vietnam): Aulacospira furtiva (Eupulmonata: Vertiginidae) and Georissa carinata (Neritimorpha: Hydrocenidae)

“…The toponymy of the area is still unsettled. We have used names of hills as in Vermeulen et al (2019a: Vermeulen, Phung et Truong, 2007 (also from the MDL) by the presence of apertural teeth. Recently, several species of Aulacospira have been described from continental Asia with more than two apertural teeth.…”

“…The Mekong Delta Limestones (MDL) are a string of limestone hills in Vietnam and Cambodia, on the west flank of the Mekong river delta (see Vermeulen et al 2019a). The hills are hundreds of kilometres distant from other limestone hills, which has led to high levels of endemism (Vermeulen et al 2007(Vermeulen et al , 2019a.…”

Land snail fauna of the Mekong Delta Limestone Hills (Cambodia, Vietnam): Notharinia Vermeulen, Phung et Truong, 2007, and a note on Plectostoma A. Adams, 1865 (Mollusca: Gastropoda: Caenogastropoda: Diplommatinidae)

“…This paper presents a revision of the genus Notharinia Vermeulen, Phung et Truong, 2007 with ten endemic species in the Mekong Delta Limestones (MDL), a string of limestone hills in Vietnam and Cambodia, on the west flank of the Mekong river delta (see Vermeulen et al 2019: fig. 1).…”

“…Seven species are new to science. Vermeulen et al (2019) illustrate the degradation of the MDL biodiversity by habitat loss. The fate of selected species is recorded in proposals for inclusion in the IUCN red lisT.…”