Zorenko T.A., Golenishchev F.N. 2015. The spermatozoa structure peculiarities of the subgenus Sumeriomys (Rodentia, Arvicolinae, Microtus) // Russian J. Theriol. Vol.14. No.1: 105–111 [in English].
Tanya A. Zorenko [zorenkot@lanet.lv], University of Latvia, Riga LV -1586, Krovald bulv. 4, Latvia;
Fedor N. Golenishchev [f_gol@mail.ru], Zoological Institute, Russian Academy of Science, Universitetkaya nab. 1, Saint Petersburg 1999034, Russia.
ABSTRACT. Owing to distinct differences in size and shape in different taxa, spermatozoa can be of a high diagnostic value. The functional and evolutionary nature of such diversity is poorly understood. The purpose of the study was to summarize the data on the differences in sperm design and linear parameters between the subgenera Sumeriomys and Microtus (the genus Microtus) and to carry out the same comparison between the “socialis” and “guentheri” groups of species within the subgenus Sumeriomys. We obtained the data on shape and size of spermatozoa in seven nominal forms of the subgenus Sumeriomys. The species of the subgenus Sumeriomys are quite similar in sperm design, which distinctly differs from that in the representatives of the subgenus Microtus. The spermatozoa of the Sumeriomys species also differ from those of the Microtus representatives in some linear measurements and quantitative indices. These data confirm the taxonomic distinctness of the social voles as an independent subgenus Sumeriomys. Within the subgenus Sumeriomys some essential differences were revealed in sperm dimensions. The largest spermatozoa are observed in the species of the “guentheri” group, especially in M. guentheri (a head length 7.60 mk). In M. hartingi they are slightly smaller in size (in two subspecies correspondingly 6.96 and 7.25 mk). In three nominal forms of the “socialis” group the spermatozoa are smaller (a head length 7.01–7.21 mk), than in the “guentheri” group. The ratio of head length to its width in M. guentheri and M. hartingi is respectively 1.5 and 1.46, while in the “socialis” group, 1.42–1.47. In voles of the subgenus Microtus it is 1.8–2.4. The length of the medium part of spermatozoon’s tail is the most variable character. The ratio of the sperm tail medium part length to head length in Microtus is higher than 2.8 (2.8–3.2), but in Sumeriomys it is lower than 2.8 (2.4–2.7).
KEY WORDS: Microtus, Sumeriomys, spermatozoa, taxonomy.