Morphological and genetic identification of freshwater Dreissenid Mussels: Dreissena polymorpha (Pallas, 1771), and D. rostriformis bugensis Andrusov, 1897 (Dreissenidae, Bivalvia)

Abstract

Dreissenids display a high diversity of shell morphology. Taxonomic keys based on shell morphology are not always able to differentiate these species with confidence. In such cases, genetic markers are useful in addition to morphological features. Typical and atypical dreissenid individuals are analyzed in this study. It is demonstrated that the position of ventrolateral angle at the anterior part of a valve (3–5 mm from the anterior shell edge) is a reliable diagnostic feature for atypical D. polymorpha and D. r. bugensis.