Abstract
A total 300 fishes belonging to Cyprinus carpio were collected from the lesser Zab river near alton- kupri town, south of arbil city in northern Iraq, during the period from November 2000 until the end of October 2001. Fishes were infected with the monogenetic trematode Dactylogyrus minutus, the cestode Bothriocephalus acheilognathi and larval stage of the nematode Contracaecum sp.. no significant differences were noted in the infection of male and female fishes with these Parasites.
The infection with D. minutus was decreased with the increase of fish length, while the infection with Contracaecum sp. was increased, but the infection with B. acheilognathi was not affected with fish length groups. The infection with these three parasites showed monthly fluctuations. Generally, it was high during spring and summer and low during autumn and winter.