Study of the prevalence of parasitical skin infections of rainbow trout (250 - 300gr) in commercial fish farms of East Azarbaijan province

Parasitic infestations constitute an important part of aquatic animal diseases. In order to study the prevalence of parasitic skin infections of rainbow trouts in mordad of 1385, 5 breeding farms were selected and 386 rainbow trouts with the body weight of 250-300 gr were collected randomly from each farm and examined. Of the 1930 examined specimens of 5 farms in this study, 14 were infected by Ichthyophthirius sp. (0.7%), 890 by Trichodina sp. (46.1%), 41 by Dactylogyrus sp. (2.1%), 111 by Gyrodactylus sp. (508%) and 874 were without any parasitic infections (45.3%). The highest infection rate belonged to Trichodina sp.