bacteriological studies and using natural immunostimulants for control columnaris disease in fresh water fish

The main objective .of the present study was to isolate and identifyFlavobacterium columnare the most common bacterial cause of mortalitiesand low productivity among cultured fish, and try to control it. This studywas carried out in The World Fish Center, Abbassa, Abou Harnmad,Sharkia Govemorate, Egypt. A total number of 480 clinically and grosslydiseased Oreochromis niloticus and 480 clinically and grossly diseasedClarias gariepinus were collected along one year from World Fish farmsand transferred alive or recently dead to World Fish laboratory andsubjected to full clinical and bacteriological examinations.The results of this study could be summarized as follows:1- Main clinical findings in diseased examined fish were showed loss ofappetite, loss of balance and respiratory manifestations, in addition toswimming near the surface, gasping and engulfing the atmosphericair and floating near the surface with