The epilithic and epipelic diatom flora of the Balikhli River, Northwest Iran

The taxonomic composition of diatom flora of the Balikhli River (Balikhli Chay), Northwest Iran, was studied from October 2013 through September 2014. In total 109 taxa belonging to 50 genera were identified. Nitzschia (18 spp.), Navicula (9 spp.), and Gomphonema (7 spp.) were the most abundant genera. Twenty-five diatom species were found in more than half of the samples; among them, Nitzschia inconspicua, Planothidium lanceolatum, Amphora pediculus, Navicula trivialis, Gomphonema olivaceum, Nitzschia palea, and Rhoicosphenia abbreviata were the most abundant taxa, which are characteristic for alkaline and eutrophic waters. The centric diatoms constituted only 4.54% of all identified taxa. In this study 20 taxa were recorded for the first time for the aquatic ecosystems of Iran.