Species composition and ecological and geographical characteristics of algoflora of plankton of the Usa river (Samara region)

The list of algae obtained by 35-year survey of the of Usa River planktonic algal flora is presented. The phytoplankton of the river is distinguished by high taxonomic diversity. It contains 335 algae taxa with a rank below the genus level. The main role in the formation of the algoflora of the river plankton belongs to planktonic algae with a wide geographical distribution, indifferent to the water salinity, alkaliphilic and pH indifferent species and species - indicators of the β-mesoprobe zone of organic pollution.