Epilithic diatom diversity in Golestan waterfall

Waterfalls are aquatic ecosystems that a few studies on biodiversity of this freshwater systems were reported. Golestan waterfall is one of the outstanding waterfalls in eastern end of Golestan National Park. This study was conducted to to identify epilithic diatoms of this waterfall as a component of biodiversity of this ecosystem, due to the fact that no study has been done on algal flora in this. Sampling was done at seasonal interval from stony substrates. The results were revealed 24 including 47 species which all taxa belonged to the class Bacillariophyceae. Cymbopleura with 5 species was the most species rich genus following by Gomphonema and Navicula with 4 species. Achnanthidium minutissimum, Amphipleura pellucida, Cymbella affinis, Cymbopleura kuelbsii and Gomphonema pumilum were the most abundant taxa. Delicatophycus verenae M.J.Wynne, Stauroneis separanda Lange-Bertalot & Werum and Tryblionella brunoi (Lange-Bertalot) Cantonati & Lange-Bertalot are recorded for the first time for diatom flora of Iran. Due to the few diatom studies there are no valid flora on diatoms in Iran, thus detailed and local studies can improve the knowledge on diatoms.