Plankton diatoms (Fragilariophyceae, Bacillariophyceae) from the middle part of Irtysh River
Investigation of diatoms from plankton of the Irtysh River using light microscopy resulted in findings of 122 species of pennate diatoms from 38 genera. We found five species of Fragilariophyceae and 117 species of Bacillariophyceae. The genera Nitzschia (14 species), Navicula (8), Sellaphora (7), Pinnularia (7), Surirella (7) are characterized by the largest number of species. For the first time for the Middle Irtysh, 61 species from 30 genera were found. Micrographs of the identified species are given. The list of diatoms has been refined and expanded.