RT Journal Article ID 3c5e0907789f854b A1 Genkal, S. I. T1 Thalassiosira duostra C. Pienaar (Bacillariophyta) - a New Species for the Flora of Ukraine JF International Journal on Algae JO IJA YR 2019 FD 2019-06-12 VO 21 IS 2 SP 191 OP 197 K1 Bacillariophyta K1 Thalassiosira K1 morphology of frustule K1 scanning electron microscopy K1 Ukraine AB The study of archive materials has made it possible to specify the species composition of the genus Thalassiosira Cleve. In the Danube region of the Black Sea, a representative of Centrophyceae (Thalassiosira duostra), which is new for the flora of Ukraine, was discovered. In the analyzed material, the number of central fultoportulae was greater than in the original description, and they are arranged in a circular pattern. However, all quantitative (valve diameter, number of central and marginal fultoportulae) and qualitative (areolae shape and their arrangement on the valve face) characteristics correspond to the published data. According to the general valve outline, the structure and arrangement of central and marginal fultoportulae as well as quantitative characteristics, T. duostra is very similar to Conticribra weissflogii (Grunow) Stachura-Suchoples & Williams, and Thalassiosira faurii (Gasse) Hasle which may have caused inaccuracies in these species' identification. PB Begell House LK https://www.dl.begellhouse.com/journals/7dd4467e7de5b7ef,125b19677fdcc74c,3c5e0907789f854b.html