Expansion of invasive diatom species Didymosphenia geminata (Lyngb.) M.Schmidt and Diadesmis confervacea (Grun.) Hustedt in the waters of Serbia

For the first time in Serbia, the presence of Didymosphenia geminata was recorded in lakes of the Šar Planina mountain (Urošević, 1994). Subsequently, it was observed in the rivers Danube, Tisa, Sava. Detailed range of D. geminata spreading in the waters of Serbia was given by Subakov-Simić et al. (2006). Throughout monitiring rivers and channels in Serbia we recorded expand of this species in norther part of Serbia, Vojvodina, in the channel Novi Sad-Savino Selo. Diadesmis confervacea is diatom with a mainly tropical distribution. Majority of the findings in Europe originate from quiescent waters of botanical gardens and it is common in power plant discharges (Coste and Ector, 2000). They suggest it is invasive species that may spread further if global warming persists. While monitoring rivers and channels of Serbia from 2002 till 2013 we noticed the rapid expansion of distribution of D. confervacea. It occupied new habitats and nowadays can be found in the rivers Jegrička and Zasavica, as well in the channals Bački Petrovac-Karavukovo, Bečej-Bogojevo and Kikindski kanal in Vojvodina.6th Balkan Botanical Congress, Rijeka, September 14-18, 201