Abstract
The Eurasian minnow, inhabiting the vast area of Northern Eurasia has recently attracted close attention of ichthyologists. The new undescribed forms and phylogenetic lines are being revealed. The morphological variability of populations of the Eurasian minnow from water bodies of Kazakhstan has not been sufficiently studied, and its taxonomic position remains unclear. This paper presents the results of the analysis of external meristic characters and the first data on squamation variability of the Eurasian minnow from the Irtysh River in East Kazakhstan. The number of fin rays is within the variability of previously studied populations from the rivers belonging to the basins of the Irtysh River and Lake Balkhash. The number of lateral line scales, as well as its length, are noticeably variable. Belly and breast squamation is also individually variable.