Study of infection intensity of Copepods parasites from the genus (Ergasilus) on gills of carp fishes (Cyprinus carpio L) (endoparasites), and on fish's tail region (exoparasites) for big sizes and small sizes (Fingerlings) at three seasons (summer, winte

This study was conducted to determine the infection intensity of Copepods parasites from the genus (Ergasilus) on gills of carp fishes (Cyprinus carpio L.)   (endoparasites), and on fish's tail region (exoparasites). For big sizes and small sizes (Fingerlings) at three seasons (summer, winter and autumn), specimens were collected from Martyr monument pond, Baghdad Iraq. Results showed the high infection intensity by this copepods and less infection intensity on the fish's tail region for big and small specimens. The study also showed a high infection intensity at summer season and less on autumn season, and very short infection intensity on winter season, this is may be can explain by the different on pond water temperature seasonally, food supplying and the fishes movement activities. Results were showed that the infection intensity was higher at the fingerlings than in big fishes, that was may be due to the ability of small sizes fingerlings to move and touch with the algae (Spirogyra, horse tails) and other aquatic plants living near the edge of the pond comparing with the middle and deep water of the pond