الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 149 |  |  |
| | | from | 149 | | |
Abstract
A total number of 1702 O. niloticus with an average body weights (25±10g and 50±15g), were obtained alive from Abbassa fish farms, Sahl El-Hosainia private fish farms in Sharkia governorate and Edco private fish farms in Behiera governorate and wild Nile tilapia from Bahr Moes in Zagazig and Al-Riah El-Tawfiki in Benha during the period from may 2012 to may 2014 in all seasons. The fish were subjected to clinical, P.M., mycological and histopathological examinations.
The clinical signs and postmortem findings in the infected O. niloticus were recorded as follow, O. niloticus infected with I.hoferi, clinical signs were sluggish movement, dark discoloration the external body, extensive areas of scales loss, erosions in the skin and belly was protruded. The post mortem lesions were severe congestion in visceral organs (liver, spleen and kidneys) with prominent enlargement of these organs especially the liver and sometimes presence of grayish nodules on it. While, clinical signs of O. niloticus infected with Branchiomyces sp. were weakness, lethargy and respiratory distress which represented by swimming vertical position to gasp the air, surfacing, accumulating at the water inlet with rapid operculur movement and finally die with open mouth. Gills appeared congested in acute condition and white-coloured in chronic condition when the disease progressed as a result of necrosis of gill tissue .
PCR is an excellent and rapid tool for diagnosis of Ichthyophoniasis and Branchiomycosis which needs further studies
The histopathological alterations of the naturally infected O.niloticus, in case of I.hoferi, the liver of naturally infected.