Sheremetyeva I.N., Kartavtseva I.V., Voyta L.L., Kryukov A.P., Haring E.
В журнале Journal of Zoological Systematics and Evolutionary Research
Год: 2009 Том: 47 Номер: 1 Страницы: 42-48
The vole Microtus maximowiczii Schrenck, 1858 is a widely distributed species inhabiting humid biotopes of the forest zone in East Asia.It comprises three subspecies: M. m. maximowiczii Schrenck, 1858, Microtus m. ungurensis Kastchenko, 1913, and Microtus m. gromovi Vorontsov, Boeskorov, Lyapunova and Revin, 1988. The description of the latter subspecies was based on one subadult individual only. Here, we present a morphological investigation of the three subspecies and relate the results to the karyological variation observed in M. maximowiczii. In a morphometric analysis, 124 skulls of the three subspecies were studied, including seven of M. m. gromovi, which have been collected near Ayan village at Ohotsk sea coast (Russian Far East). The samples of M. m. gromovi clustered separately from the other subspecies of M. maximowiczii. In average, M. m. gromovi proved to be considerably smaller than the others. The analysis of the third upper molar (M 3) revealed that the majority of individuals of M. m. gromovi (from Ayan and from the coast of Lake Bolshoe Toko) possessed a complicated shape of M 3. In the karyological analysis, the number and morphology of chromosomes in all three M. m. gromovi individuals investigated were stable and equal: 2n = 44, NF = 60. While the same chromosome formula is also found in the other subspecies of this karyologically highly variable species, the individuals from Ayan possess peculiar characters: pericentric inversions in the ?rst and fourth chromosome pairs, a large acrocentric chromosome and additional euchromatin in the 10th pair. In total, the results con?rm a distinct systematic position of M. m. gromovi and consequently, this taxon should be raised to species status. A redescription of Microtus gromovi Vorontsov, Boeskorov, Lyapunova and Revin, 1988, stat. nov. is given.
