ABSTRACT
The present study was carried out on aquarium fish to diagnose and control the Ichthyophonosis disease. A total of 200 aquarium fish [Veiltail, Tetras species, Guppies and Swordtail fish] collected from aquarium fish breeder in Giza market were found to be infected with Ichthyophonus hoferi [I. hoferi] representing 86.7%, 52%, 50% and 40% respectively. The general clincial signs in infected fish were sluggish movements, dull colours and ascites. Different fish species showed variety of clinical symptoms before death while others were apparently normal. The post-mortem examination showed white nodules mainly in liver, kidney, muscles and intestine in both moribund and apparently healthy contact fish. Squash preparation of nodules showed pathognomonic germinating spores and hyphal formation short time after fish death. Histopathological alterations in tissue sections stained with Haematoxylin and Eosin [H and E] as well as Periodic Acid. Schiff method [PAS] of different infected organs were described. The control measures for restricting this disease were reported and discussed