A dichotomous PCR–RFLP identification key for the freshwater mussels (Bivalvia: Unionida) of Peninsular Malaysia

Abstract

Accurate species identification is the basis for successful species conservation and research, but extensive phenotypic plasticity in freshwater mussel (Bivalvia: Unionida) species often leads to misidentification by morphology alone. Molecular techniques have proven a powerful alternative tool for identification of freshwater mussels in North America and Europe. Unfortunately, no such tools are currently available for tropical mussels, which are subject to particularly severe habitat alteration and destruction. We developed a PCR–RFLP key for the freshwater mussel fauna of Peninsular Malaysia, comprising nine native and one non-native species from seven genera and three unionid subfamilies (Gonideinae, Rectidentinae and Anodontinae). The key enables identification of each species in two to four single digestion steps using six restriction endonucleases. All species can be identified using a single PCR fragment of 374 bp length (Histone H3) with the exception of two Pseudodon species, which can be differentiated through amplification and subsequent digestion of a 709 bp CO1 gene fragment. Reliability of the key was tested with specimens from 46 populations sampled from 13 different river basins of Peninsular Malaysia.