Abramov Sergey A, Lopatina Natalya V, Litvinov Yuri N
Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, ul. Frunze 11, 630091, Novosibirsk, Russia.
Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, ul. Frunze 11, 630091, Novosibirsk, Russia.
Zoology (Jena). 2017 Aug;123:91-100. doi: 10.1016/j.zool.2017.07.004. Epub 2017 Jul 19.
The Olkhon mountain vole (Alticola olchonensis) is an endemic species of the Lake Baikal area with an extremely restricted range. We investigated the pattern of differentiation of cranial shape and size in five isolated insular populations of A. olchonensis from the Baikal islands (Olkhon, Hubyn, Borokchin, Ogoy, and Zamogoy). The ventral aspect of the cranium was analysed using landmark-based geometric morphometric methods While the sexes of A. olchonensis did not differ regarding cranium size and shape, multivariate statistical analyses showed that there were inter-island differences in skull morphology. Voles from the four small islands were similar in cranium size; the large skull size of voles inhabiting the Olkhon Island may be due to the more favourable habitat conditions on Olkhon. Shape differences among island populations were not associated with the geographic distances between islands. The voles from Borokchin Island differ the most in skull shape compared to other island populations. The combination of reduced gene flow among island populations (due to isolation and drift during population fluctuations) may be a suitable explanation for the significant differences in skull shape among island populations of A. olchonensis.
奥尔洪山地田鼠（Alticola olchonensis）是贝加尔湖地区的特有物种，分布范围极其有限。我们研究了来自贝加尔湖岛屿（奥尔洪岛、胡宾岛、博罗钦岛、奥戈伊岛和扎莫戈伊岛）的五个孤立岛屿种群的奥尔洪山地田鼠颅骨形状和大小的分化模式。使用基于地标点的几何形态测量方法分析了颅骨的腹面。虽然奥尔洪山地田鼠的两性在颅骨大小和形状上没有差异，但多变量统计分析表明，岛屿间的颅骨形态存在差异。来自四个小岛的田鼠颅骨大小相似；居住在奥尔洪岛的田鼠颅骨较大，可能是因为奥尔洪岛的栖息地条件更优越。岛屿种群之间的形状差异与岛屿之间的地理距离无关。与其他岛屿种群相比，博罗钦岛的田鼠颅骨形状差异最大。岛屿种群之间基因流动减少（由于种群波动期间的隔离和漂变）可能是奥尔洪山地田鼠岛屿种群颅骨形状存在显著差异的一个合理原因。
