RT Journal Article ID 172c010b5d2a7712 A1 Genkal, S. I. A1 Okhapkin, A. G. T1 Centric Diatoms (Centrophyceae) of the Lower Reaches of the Oka River (Russian Federation) JF Hydrobiological Journal JO HYD YR 2013 FD 2013-05-20 VO 49 IS 3 SP 41 OP 57 K1 the Oka River K1 the tributary of the Volga River K1 phytoplankton K1 diatoms K1 Centrophyceae K1 electron microscopy AB A total of more than 30 species and varieties of centric diatoms of 10 genera was found in phytoplankton of the lower reaches of the Oka River. They included algae species − new for the flora of the river (Actinocyclus normanii, Contricridra weissflogii, Cyclotella ambigua, C. choctawhatcheeana, C. marina, Stephanodiscus delicatus, S. volgensis, Thalassiosira faurii, and T. incerta), and also for the flora of Russia - Cyclotella marina. Both freshwater and brackish water algae species, and also brackish water and freshwater organisms, were found among representatives of Centrophyceae. This phenomenon is accounted for by the dynamics of abiotic conditions (climatic changes, the increase in water salinity, in the degree of contamination, and also in the trophic level) registered in water bodies of the Volga River basin from the second half of the XX century. PB Begell House LK https://www.dl.begellhouse.com/journals/38cb2223012b73f2,5fd2eeb97257d169,172c010b5d2a7712.html