Entomoneis Parikhani sp.nov., a new diatom (Entomoneidaceae, Bacillariophyta) from Aras River (Iran)

The diatom genus Entomoneis has species with unique morphology. Entomoneis has pandori-shaped fins in girdle view that are twisted around its apical axis. Entomoneis has a series of unique features such as connecting lines with different shapes, sigmoid raphe on the bilobate keel, different curtains and multiple girdle bands. Most of the species belonging to this genus are found in marine and salty habitats. In fact, the genus Entomoneis is an epicalic diatom that is found in streams with high salinity and high electrolyte concentration. No specific freshwater species have been described. In this study, a new species of freshwater diatom Entomoneis Parikhani is described based on detailed morphological observations using scanning electron microscope. During the studies that were conducted in the Ares River in the northwest of Iran. An unknown taxon belonging to the genus Entomoneis was found in Oltan village of Parsabad city. Aras River has fresh water. The special feature of Entomoneis Parikhani is its triple valve. Entomoneis genus includes diatoms with sigmoidal raphe canal and many girdle bands. This taxon has similarities with Entomoneis annagodhei and Entomoneis tenera as shown by LM and SEM observations, there are enough morphological differences to separate Entomoneis Parikhani sp. Entomoneis Parikhani sp found in fresh water and similar species found only in salt water. This new species has very small cells, delicate frustules without valve line and wide lanceolate valves. In this study, the wide distribution of this taxon in Aras River and its tributary has been discussed with water quality variables