Pathological Studies of Experimental Ichthyophonus sp. Infection in Blue Tilapia, Oreochromis aureus (Steindachner, 1864), Iraq

A total of 25 specimens of blue tilapia Oreochromis aureus were collected from ponds of Marine Science Centre, University of Basrah during the period May to June 2014 and from September to December 2015. The fish have been experimentally infected with fungi Ichthyophonus sp. blue tilapia, the fungus damages gill, liver and intestine and brings histopathological changes in their infected organs. Histopathological changes included hyperplasia, partial fusion of some lamellae and blood congestion in gill and focal necrosis in haepatopancreas tissues, fibrosis, infiltration and congestion in liver, and swelling in lamina propria and fusion of villi and hemocyte infiltration in intestine.