Investigation of the prevalence and intesity of parasitic infection in Rhodeus sericeus amarus of the Zardi River (Mazandaran)

A total of 59 specimens of Rhodeus  sericeus amarus  are  caught by handnet from two different station of Zardi River in the south-eastern costal of Caspian sea at the autumn and winter of 2009 and spring of 2010 . The fishes were transported alive to the laboratory of Shahid Rajaee site. They killed by cutting their spinal cord and then measured and weighed.The eye ,skin,gill,digestive system,muscle and the other organism´s of the specimens were examined for parasite infestation. Six parasites species were identified.These parasites are as following:  Trichodina sp. from skin and branchia, Dactylogyrus sp. from branchia, Gyrodactylus sp. from skin and branchia, Diplostomum spathaceum from eye̓ s, Postodiplostomum sp. from skin, Capillaria amurensis from intestine were found in the Rhodeus  sericeus amarus  of Zardi River.The most prevalent parasite was Trichodina sp. (49/15%) and the least was Diplostomum spathaceum(13/55%)