en fish disease fish disease پژوهشي Orginal research papers <p>  Various parasite species were found in <i>Carassius carassius</i> including <i>Diplostomum spathaceum</i>, <i>Dactylogyrus </i>sp.<i>,Gyrodactylus</i> sp. <i>Ichthyophthirius multifiliis</i> and <i>Trichodinia </i>sp . They were found in four rivers in West Azerbaijan Province (North-Western Iran) . A total of 207 live <i>Carassius carassius</i> from four rivers including Aras (72) Zariyneh (42) Nazlo (58) and Barandoz (35) were studied. Parasitological surveys were carried out on gills and external organs. The results showed that <i>Diplostomum spathaceum</i> (70.83%) <i>Dactylogyrus sp</i>. (38.88%) <i>Gyrodactylus sp.</i> ) 22.22%) <i>Ichthyophthirius multifiliis</i> (48.61%) <i>Trichodinia sp.</i> (8.33%) <i>Chilodonella sp.</i> (12.50%) and <i>Argulus sp</i>. (76.19%) were found in fish from Aras Rive so that the result showed,<i> Spathaceum </i>(63.79%) <i>Dactylogyrus </i>sp. (36.20%) <i>Gyrodactylus</i> sp. (25.86%) <i>Ichthyophthirius multifiliis</i> (44.82%) <i>Trichodinia sp</i>. (18.96%) <i>Chilodonella </i>sp. (12.06%) and <i>Argulus </i>sp. (6.89%). Argulus prevalence was greater in Barandoz River while Chilodonella <strong></strong>in Zariyneh rud River . In Barandoz River, <i>Diplostomum spathaceum </i>(65.71%) <i>Dactylogyrus </i>sp. (37.14%) <i>Gyrodactylus </i>sp. (22.85%) <i>Ichthyophthirius multifiliis</i> (31.42%) <i>Trichodinia </i>sp. (25.71%) <i>Chilodonella </i>sp. (8.57%) and <i>Argulus </i>sp. (5.71%) were reported, respectively. Finally, in Zariyneh rud river, the followings have been reported: <i>Diplostomum spathaceum </i>(76.19%) <i>Dactylogyrus </i>sp<i>.</i> (21.42%) <i>Gyrodactylus </i>sp<i>. </i>(14.28%) <i>Ichthyophthirius multifiliis</i> (52.38%) <i>Trichodinia </i>sp<i>.</i> (23.80%) <i>Chilodonella </i>sp<i>.</i> (14.28%) and <i>Argulus </i>sp<i>.</i> (7.14%). It should be noted that prevalence , intensity and host parasite relationship will be discussed in details in this article. </p> Carassius carassius, Ectoparasite, Water resources, Iran 156 164 http://jifro.ir/browse.php?a_code=A-10-1-151&slc_lang=en&sid=1 S. Rasouli Sohrab_rasouli86@yahoo.com 10031947532846002736 10031947532846002736 Yes A. Nekuifard 10031947532846002737 10031947532846002737 No D. Azadikhah 10031947532846002738 10031947532846002738 No H. Ahari 10031947532846002739 10031947532846002739 No A. A. Anvar 10031947532846002740 10031947532846002740 No A. Khodadadi 10031947532846002741 10031947532846002741 No A. Ghasemi 10031947532846002742 10031947532846002742 No