The Muja vole, Alexandromys mujanensis Orlov et Kovalskaya, 1975, was described in the result of the karyological analysis and experimental hybridization. Since the first description the Muja vole has been considered to inhabit only the Muja Valley. Some Far Eastern voles were collected in 2013 and 2014 from the Dzherginsky Nature Reserve of the Barguzin Valley (Dzhirga sample), and the Baunt Lake vicinity (Baunt sample) (Transbaikalia, Buryatia). The species from these geographic localities were identified by use of karyotypic and cytb-gene analyses. On the cytb-gene tree these voles are in the same clade with Muja voles from the type locality (the Muja Valley). The karyotype of the vole from Barguzin Valley corresponds to that previously described for the Muja voles (Meyer et al. 1996). According to the result of the shape analysis of m1 occlusal surface the sample from the Baunt Valley includes two species – A. mujanensis and A. maximowiczii. Unless more detailed analysis of the material from the different parts of the Baunt Valley is carried out, we suppose it to be inhabited by three species – A. maximowiczii, A. mujanensis, and according to the data from literature – A. oeconomus. So far as some molecular-genetic differences between Muja voles from the Dzhirga and Baunt Lake vicinity were found, the experiments on hybridization between them were set. The F1 hybridization between them were fertile. A. mujanensis taxonomic position and terms of its origination are discussed.
New Transbaikalian finds of the Muja Valley vole (Rodentia: Cricetidae: Alexandromys mujanensis)
