en fish disease fish disease پژوهشي Orginal research papers During a parasitological investigation on the fresh water fishes of North West of Iran (West Azerbaijan Province), 266 specimens of 11 fishes were examined. Fishes were collected from seven stations from Aras, Zangbar and Sarysou Rivers between summer 2001 to summer 2002. Nine protozoan species were detected; eight Cilliophora and one Rhizopoda. Cilliophora are: <em>Chilodonella </em>sp<em>., Apiosoma sp.,Vorticella sp. Ichthyophthirius multifiliis, Trichodina perphorata, Amphileptus branchiarum, Tetrahymena pyriformis, Stylonchia pustulata</em>, and the Rhizopoda species is <em>Arcella vulgaris</em>. Results show that five of those species are for the first time being reported from Iranian fresh water fishes.&nbsp; Protozoan, Cilliophora, Rhizopoda, West Azerbaijan Porvince, Iran 31 42 http://jifro.ir/browse.php?a_code=A-10-1767-1&slc_lang=en&sid=1 M. Masoumian ifro_masoumian@yahoo.com 100319475328460024440 100319475328460024440 Yes J. Pazouki 100319475328460024441 100319475328460024441 No M. Yahyazadeh 100319475328460024442 100319475328460024442 No A. Teymornezhad 100319475328460024443 100319475328460024443 No