Centric diatom diversity in the lower part of the Southern Bug river (Ukraine): the transitional zone at Mykolaiv city Author Bilous, Olena P. https://orcid.org/0000-0001-5229-3667 Institute of Hydrobiology, NAS of Ukraine, 12 Geroyiv Stalingrada Ave., Kiyv 04210, Ukraine bilous_olena@ukr.net Author Genkal, Sergey I. I. D. Papanin Institute for Biology of Inland Waters of RAS, Settle Borok, Nekouz District, Yaroslavl Region 152742, Russia Author Zimmermann, Jonas Botanischer Garten und Botanisches Museum Berlin, Freie Universitaet Berlin, Koenigin-Luise Str. 6 - 8, Berlin 14195, Germany Author Kusber, Wolf-Henning Botanischer Garten und Botanisches Museum Berlin, Freie Universitaet Berlin, Koenigin-Luise Str. 6 - 8, Berlin 14195, Germany Author Jahn, Regine Botanischer Garten und Botanisches Museum Berlin, Freie Universitaet Berlin, Koenigin-Luise Str. 6 - 8, Berlin 14195, Germany text PhytoKeys 2021 2021-05-20 178 31 69 http://dx.doi.org/10.3897/phytokeys.178.64426 journal article http://dx.doi.org/10.3897/phytokeys.178.64426 1314-2003-178-31 286CBEFF513C55E1B66F6224758AC2F6 Conticribra weissflogii (Grunow) Stachura-Suchoples & D.M. Williams, Eur. J. Phycol. 44: 482. 2009. Basionym. Micropodiscus weissflogii Grunow in Van Heurck., 1885. Synonyms. Eupodiscus weissflogii Grunow, nom. inval., Eupodiscus weissflogii (Grunow) De Toni, Thalassiosira weissflogii (Grunow) G.A. Fryxell & Hasle Morphological description. The frustule has the form of a drum, valves are almost flat, diameter 24.4-26.6 μm , 8-10 marginal processes in 10 μm , 2-5 central processes (Fig. 4E ). Ecology. Conticribra weissflogii is a planktonic diatom, from marine and brackish-water environments that also may occur in lacustric and riverine waters. It is reported to occur in a wide range of salinity 2-26‰ (representing oligohalobs to polyhalobs), especially at salinities above 5‰ ( Stachura-Suchoples and Kulikovskiy 2014 ). This taxon tends to increase in population density with rising temperature ( Lomas and Glibert 1999 ) as well as with eutrophication ( Zheng et al. 2016 ). It is also known to grow in waters with relatively high pH, around 8-9.4 ( Sala 1997 ). Distribution. This centric taxon appeared at the Mykolaiv site in the Southern Bug River; for Ukraine it was mentioned for the first time in our previous investigation (Table 1 ; Genkal and Bilous 2015 ), afterwards it was found in the tributaries of Dnipro in eastern and central parts of the country ( Berezovskaya 2019 ; Kryvosheia and Kapustin 2019 ). This is a widely distributed species: Europe, Asia, America (North and South), Africa, Australia and New Zealand; it was even found in Lake Baikal, also in the oceans over the world ( Stachura-Suchoples and Kulikovskiy 2014 ; Genkal et al. 2020 ).