Diatoms of the Tributaries of the Svir River (North-West of Russia)

This scanning electron microscopy study revealed 297 species and varieties of diatoms from 72 genera in the phytoperiphyton of the Svir River tributaries, which allowed us to obtain the first data on the species composition of Bacillariophyta in a number of tributaries of this watercourse (Yanega, Uslanka, Vazhinka, Ivina) and expand it for Oyat and Pasha. Among them, 15 species are new to the flora of Russia and 59 forms from 19 genera were identified only up to the genus rank. The greatest species richness was recorded in the Yanega (118) and Ivina (148) tributaries and the highest taxonomic richness was observed among the genera Nitzschia (25), Navicula (26) and Sellaphora (34). A similar number of species and varieties, 208 and 219, respectively, were detected in the left-bank and right-bank tributaries.