M Rostami - Departmen of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Iran.
N Alighazi

Objective: In the present study, in order to review the gills and hepatopancrease histological changes due to myxosoan infection, infected tissues of a 2 months old common carp (Cyprinus carpio) with myxosporeans were studied histopathologically under light microscope. The aim of the present study was to reveal and survey the histopathological changes of the gills and hepatopancreas due to Myxozoan infection in common carp. Method & Materials: The routine microscope processor were performed by using biopsied tissues of gills and hepatopancrease of the host fish. The examined tissues were fixed in 10% formalin. After tissue processing, the 5 micrones tissue sections were stainednin hematoxylin & eosin (H&E), and examined. Results & Conclusion: The changes in gills were edema, hyperplasiain branchia epithelial cells increasing in mucosal cells, hyperplasia mround the branchial cartilage, sedimentation of melanin pigment and fussion of lamella, Moderate infiltration of leuckocytes and macrophages. In liver, necrosis of hepatocytes, and infiltration of spores and macrophages into the lumen of portal veins were lead to miural thrombosis. Histozoic myxosporean sp. which causes the emaciation disease in fish, are highly pathogenic to them. In order to control the disease, and to avoid the increasing economic losses of the parasite, consideration and assessment of the infection and the pathological effects are requisite. Accordingly, the pathological changes of tissues induced by myxosporeans, were showed that the majority of infections were found in the brancial epithelial cells and in the lumen of portal veins of hepatopancreas of examined fish in the present study.

myxosporean, protozoan, cellular changes, common carp