Studies on the Parasitic Diseases of Some Fresh Water Fishes in Dakahlia Governorate

Summary:-In the present study, some parasitic diseases infesting fishes of River Nile and lake Manzala at Dakahlia Governoraie has beeninvestigated .The results of this work could be sutnmerized as follows:(1) The clinical signs and postmortum lesions in infested fishesrevealed congestion, hyperimic gills with excessive mucoussecretion in monogenetic infestation, also the gill of Mugil capiteinfested with Caligus curtus and Ergasilus sarsi showedcongestion and destruction of gill lamellae with highly amount ofmucous secretion. Skin infestation with Lernaea cyprinacaecaused haernorrhagic ulcers and dark colouration. The infestionwith intestinal helminthes revealed the signs of emaciation andhaemorrhage on skin and congestion of intestinal wall.(2) The prevalence of parasitic infestation among 355 fish collectedfrom River Nile and 399 fish from lake Manzala were 42.25% and40.85% respectively.(3) The highly parasitic infestation was noticed 111 Clarias lazera illRiver Nile and lake Manzala (62.14% and 49.260/0 respectively).(4) The sesonal prevalence of parasitic infestation showed highestpercent of infestation in fishes collected from River Nile was inAutumn (52.43%) and the lower percent was in Summer season(35.29%). The high prevalence of monogenean parasites wasmostly during Autumn season (26.83%) and low in Spring season