TAXONOMIC STUDY OF DIATOMS IN ZAYANDEH ROOD DAM LAKE

Diatoms samples in Zayandeh Rood Dam Lake were taken in four stations from surface, 0.5 and 3 m depths of water in three replicate by Nansen sampler. Additional samples were taken from the surface with plankton net. Diatoms samples fixed with 4% formaldehyde and were concentrated and identified using microscope at 400 x. Salinity, NO3, PO4 and SO4 were measured using standard methods (APHA). In the present study, 53 species and 23 genera were identified. Nitzschia was dominant genera with 12 species and Cyclotella meneghiniana Kutz. was dominant species in all stations and seasons. Temperature, pH, EC and DO were measured at site. The study revealed that, the Zayandeh Rood Dam lake is an oligo- mesotrophic water body.