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

The diatom 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 species belonging to this genus are found in marine and saline habitats. In fact, the genus Entomoneis is an epipelic diatom that is found in streams with high salinity and high electrolyte concentration. To date, no specific type of freshwater has been identified for this species. In this study, a new species of freshwater diatom, Entomoneis parikhani, is described based on detailed morphological observations using a scanning electron microscope. The samples were collected the Aras River near Oltan village of Parsabad city in the northwest Iran. A special feature of Entomoneis parikhani is its triple valve. The genus Entomoneis comprises of diatoms with sigmoidal raphe canals and girdle bands. This taxon is similar to Entomoneis annagodhei and Entomoneis tenera, as shown by LM and SEM observations, and there are sufficient morphological differences to separate Entomoneis parikhani. This new species had very small cells, delicate frustules without valve lines, and wide lanceolate valves. In this study, the wide distribution of this taxon in the Aras River has been evaluated.