ABSTRACT

The aim of this study was to determine the rate of helminth infection in rudd, (Scardinus erythrophthalmus L. 1758) between spring and autumn seasons. A total of 87 rudd fish were investigated. Of these, 66 were infected with four species [Dactylogyrus difformis (Monogenea), Diplostomulum spathaceum metacerceria with Asymplodora markewitschi (Digenea), and Hysterothylacium sp. (Nematoda)]. During the study, it was noted that 46 out of 87 hosts were infected with D. difformis .The level of infection for this species was found to be 93% in the spring but it was 13% in the autumn. For D. spathaceum which was the second dominant species, 365 parasites were found on 71 of 87 hosts. The maximum infection level for this species was 95% in the autumn. A total of 55 A. markewitschi could be found on 3 fish only during the spring. During the study, the lowest infection rate of the four species was that of Hysterothylacium sp. of which only 8 specimens were found on 7 fish.