SPONTANEOUS HISTOPATHOLOGICAL LESIONS OF THE INTESTINES, LIVER, PANCREAS AND HEART OF THE FRESHWATER FISH MASTACEMBELUS MASTACEMBELUS (BANKS & SOLANDER 1794)

Abstract

The purpose of this study was to report spontaneous histopathological lesions of the intestines, liver , pancreas and heart of Mastacembelus mastacembelus collected from Tigris river, Ninevha Province, Iraq. Parasitic infections of the intestinal tissues were common in these fishes and were in the form of parasitic nodules in the intestinal submucosa consisting of the parasites or their larval stages surrounded by fibrous tissue capsules. Focal or diffuse infiltrations of mononuclear cells (macrophages, lymphocytes and plasma cells) were seen involving most of the intestinal layers. Patchy degeneration and desquamation of the intestinal epithelium were observed in some of the infected fishes. The livers of these fishes showed dilatation of the sinusoids, focal hepatitis with the infiltration of inflammatory mononuclear cells, and portal fibrosis. Myocarditis occurred in these fishes and was characterized by the infiltration of mononuclear cells between the bundles of myocardial fibers. A similar infiltration of mononuclear cells was seen in the pancreatic srtoma. From results of this study it was concluded that naturally – occurring pathological lesions are common in fishes of the species M. mastacembelus and that further studies are needed to a certain the nature of the etiological agents