Algal and cyanobacterial diversity in saline rivers of the Elton Lake Basin (Russia) studied via light microscopy and next-generation sequencing

Naturally saline rivers are known in various regions of the world. Saline with a salinity gradient from source to mouth particularly interesting, because range is structure-forming factor hydrobiont assemblage. Such represented by Elton Lake Basin Volgograd region Russia (the Bolshaya Samoroda River and Malaya River). Herein, we analyzed taxonomic structure species diversity microalgae Cyanobacteria flowing into light microscopy next-generation sequencing. The differences possible causes inconsistencies results obtained these methods discussed. In total, 91 taxa microorganisms were identified integrated approach assemblages middle course River, 60 – river mouth. those hypersaline was lower: 27 23 Next-generation sequencing allowed us refine expand list studied due detection which hard identify, low-abundance taxa, as well extremely small-cell forms. Some discrepancies between data indicate advantage simultaneous use both for study algae communities. comprehensive provides most accurate correct added morphological descriptions 18S rRNA 16S partial sequences. Generally, 18 have been recorded first time belonging phyla Chlorophyta (Borodinellopsis sp., Chlorochytrium lemnae Cohn, Caespitella Halochlorococcum Tetraselmis cordiformis (H. J. Carter) F. Stein), Ochrophyta (Pseudocharaciopsis ovalis (Chodat) D. Hibberd, Characiopsis Poterioochromonas stipitata Scherffel, Chrysolepidomonas sp.), Euglenozoa (Euglena bucharica I. Kisselev, Lepocinclis tripteris (Dujardin) B. Marin & Melkonian, Phacus orbicularis K. Hübner, P. parvulus G. A. Klebs), Cryptophyta (Hemiselmis cryptochromatica C. E. Lane M. Archibald, Rhodomonas Hanusia phi Deane), Haptophyta (Pavlova (Johanseninema constrictum (Szafer) Hasler, Dvorák Poulícková). Seven detected algal cyanobacterial (Tetraselmis cordiformis, T. arnoldii (Proschkina-Lavrenko) R. Norris, Hori Chihara, tetrathele (West) Butcher, Pyrobotrys elongatus Korshikov), (Hanusia phi), (Synechococcus (Nägeli) Nägeli, Oscillatoria simplicissima Gomont).