Study of the Genus Pinnularia (Naviculales, Bacillariophyta), in the Taleghan River and a New Record for Diatoms Flora of Iran

The diatoms are widespread organisms that occurred in various environments like soil, marine, freshwater, and even in extreme conditions. Taleqhan River is one of the main tributaries of Sepid Roud, the second longest river in Iran with approximately 670 km length.  During the sampling from eight stations in the Taleghan River and Dam, Pinnularia lundii var. linearis Krammer was identified as a new record for diatoms flora of Iran. Given the importance of Pinnularia genus as an indicator of pollution, it was discussed together with Pinnularia brebissonii (Kütz.) Krammer in this paper. This study was performed during November 2017 to October 2018 on the sediments monthly in the North of Iran. The most characteristic morphological features were the valve outline, density of striae, hexagonal-shaped central area, non-deflected proximal raphe endings and capitated apices. The most similar species to this taxon are P. subanglica Petersen and Pinnularia biceps Gregory. They have deflected proximal raphe ending, unlike Pinnularia lundii var. linearis.