Physella acuta (Draparnaud, 1805) (Mollusca: Gastropoda: Physidae) in the Dong Nai River Basin (Lam Dong Province, Vietnam): Genetic and Morphological Identification

Alien freshwater mollusks belonging to the genus Physella (Gastropoda: Physidae) were for the first time discovered in the basin of the Dong Nai River (Vietnam). The mollusks were described as Physella acuta (Draparnaud, 1805) on the basis of the analysis of morphological traits and the nucleotide sequence of a fragment of the mitochondrial gene encoding the first subunit of cytochrome c-oxidase (COI). The present paper summarizes the data on the distribution of this species in the water bodies of Vietnam, provides the morphological characteristics of the studied individuals, and also compares them with other populations of this species found in tropical and subtropical areas. It has been demonstrated that, despite the more than 20-year history of Physella acuta records in Vietnam, this species remains relatively rare in the country's water bodies. The presence of the individuals of different size in the studied mollusk sample suggest that a self-reproducing population of Physella acuta has formed in the Dong Nai River basin.