The Detection of Ichthyophonus hoferi in Naturally Infected Fresh Water Ornamental Fishes

Abstract

Ichthyophoniasis is one of the most important systematic infections among different species of fishes that caused by Ichthyophonus hoferi. In the present study, we have reported this parasite from two species of ornamental fish, black tetra (Gymnocorymbus ternetzi) and tiger barb (Pentius tetrazona) in Ahvaz-Iran. Examined fishes had marked signs such as abnormal swimming, lethargy, swelling abdominal and low rate mortality. In this study, the two phases of life cycle of I. hoferi involving active and passive detected. The obvious internal sign was white cysts and nodules, which embedded in infected spleens. The cysts were full of schizonts that were surrounded by collagen fibers and many eosinophilic cells. Plasmodium spherical bodies with variable sizes were detected by microscopic examination of wet mount squash from the infected organs. In addition, histopathology studies showed that there were many granulation tissues surrounded by multilayer connective tissues in the infected tissues. Tissue samples were also isolated and put in to Minimum Essential Medium (MEM) to detect the germination of Ichthyophonus hoferi for distinguish Ichthyophoniasis from Mycobacterial infections.