عنوان مقاله [English]
Clinostomum complanatum is a common parasite between human and fish (zoonose) .It can be locally found in different tissues of the fish. A large spectrum of freshwater bony fish; including Capoeta capoeta gracilis, harbour this parasite. It`s an endemic fish in freshwater such as Shirood River in the western part of Mazandaran province. In this study, 120 fish were caught using cast net along Shirood River in two stations which is situated at the River entrance to the Caspian Sea and the second was in the upper part, during two seasons; winter and spring. The samples were tested, the reaction of immunity system in infected fishes to Clinostomum complanatum examined for changes of abundance perecentage of leukocytes. After biometrical measurments, samples were bleeded through cutting of peduncle and the infection to Clinostomum complanatum, in tissues and organs studied. White blood cells counts and differential cell count were done for infected and uninfected fish in the seasons and the stations.Statistical analysis of differential white blood cell count showed that in the first station, mean of lymphocyte, neutrophil and monocyte had significant difference between infected and uninfected fish (P<0.05). Mean of lymphocyte, neutrophil and eosinophil had significant difference between infected and uninfected fish in second station (P<0.05). The results showed that infection to the parasite exceeded in females in second station in Spring.The highest infection rate of Clinostomum complanatum metacercaria was observed in gills, under the opercolum, pharynx, muscles, under the skin, inside the muscle around fins, under the pupil of the eye, in the mouth and abdominal cavity. The metacercaria were observed inside the cysts in yellow, gray and black colors. Contamination intensity and mean of white blood cells, in females in second station in spring exceeded the first station and during the winter which may have caused by high water salinity in first station and decrease of first intermediate host snails and male lesser attendance during gonadal maturation.