biodiversity of euglenophyta species from tajan river (mazandaran- iran) during 2011-2017

the objective of this study is to investigate the biodiversity of euglenophta species from tajan river of mazandaran province (north of iran). a total of about 600 samples were collected from 9 stations (from soleyman tange dam to the caspian sea) during 2011-2017. totally 67 taxa (62 species + 5 varieties and forms) distinguished that all belong to class of euglenophyceae. 2 orders of euglenales and eutreptiales existed that each of them had 6 and 5 genera, respectively. five families identified in this division that were, euglenaceae, peranemataceae, phacaceae, astasiaceae, and eutreptiaceae. among them, phacaceae with 32 and euglenaceae with 26 showed highest and peranemataceae with only one species showed the lowest species. results also showed that order euglenales had the highest biodiversity and was dominant order (59 species).the phacaceae was dominant family with 2 genera and 32 species, while phacus sp. was dominant genus including 20 species. referring to the stations, the highest number of species seen in station 7 (44 species). with respect to the importance of the tajan river in the north of iran for drinking and agriculture activities, current results can be useful for assessing and monitoring of water and sediment quality in this region.