Morphological Differentiation of Altai Osman ...

Variability of osteological characters of Altai osmans of the genus Oreoleuciscus in the Tuin River is studied. Two morphological forms are discerned on the basis of multivariate analysis of 13 indices characterizing proportions of neurocranium and splanchnocranium in the population. One of them may be considered as the source one in formation of the dwarf form of Lake Orog in the process of cyclic diversification. The obtained result confirms a possibility of sympatric diversification of fish in the river ecosystems.