摘要：The study was conducted on epipleic diatoms in a lotic ecosystem. The Al-Shamiyah River was selected which is a distance from industrial activities. Four sites along the river were selected for sampling during the period from March 2013 to February 2014. A total of 173 species of epipelic diatoms were identified. The pennate diatoms predominated and represented about 92.49% of the total diatoms, while centric diatoms formed only 7.51%. The total number of diatoms ranged between 185.1 - 422.34 cell × 104/cm2. Some of the pennate diatom species were Achnanthes affinis Grunow, Achnanthes mintussima Küetzing, Cocconeis placentula var. euglypta (Ehr.) Cleve, Cymbella affinis Küetzing, Diatoma vulgare Bory, Fragilaria capucina Desmazieres, Gomphonema angustatum var. productu Grun., Navicula lanceolata (Ag.) Kuetzing, Navicula radiosa Küetzing, Navicula viridula Küetzing, Nitzschia palea (Kutz.) W. Smith, Nitzschia romana Grunow. The physicochemical and epipelic algae species indicated that the water quality of the river was clean to moderate water quality.
关键词：Diatom; Epipelic Algae; Lotic System; Euphrates River
