S Haghighi Karsidani - International Sturgeon Research Institute, P.O. Box ۴۱۶۳۵-۳۴۶۴, Rasht, Iran
I Sharifpour - Iranian Fisheries Research Institute, Tehran, Iran
A Shenavar Masouleh
J Abolghasemi

Objective: Motile aeromonads are causing hemorrhagic septicemia in fresh water fish. These usually occur in waters with high organic material and high temperature. Nowadays, one problem in culturing warm water fish relates to these bacteria. Clinical signs of infection with these bacteria include hemorrhages of skin and gill, lethargy eclution and mortality in Ctenopharyngodon idella. In this study, bacterial and histopathological lesions in selected organs of C. idella were studied. Method & Materials: Specimens from three fish with clinical signs, including hemorrhage and congestion in skin and gill, punctuate hemorrhages in muscles and congestion of kidney, paleness of liver randomly were collected. Tissue of muscle, kidney, liver and intestine were histopathologicaly examined and also samples from kidney, liver and spleen for bacterial investigation were collected based on standard methods. Results & Conclusion: Isolation of rods gram negative bacteria determined as Aeromonas sobria by using the tests previously described by other investigators. Microscopic examination of the tissues revealed histopathologic changes including hemorrhages, necrosis and degeneration of muscular cells and hemorrhages, appearance hyaline, rupture in kidney and shrinkage of tubules and necrosis of interstitial tissue and distention Bowmans space in kidney .in liver degeneration of hepatocytes, congestion of blood vessels were seen, congestion, necrosis and degeneration of sub-mucusal in the intestine tissue. The clinical, histopathological and bacterial examination results indicated that Aeromonas sobria similar to other motile Aeromonases caused histopathological signs in Ctenopharyngodon idella.

Ctenopharyngodon idella, Aeromonas sobria, hemorrhagic septicemia, necrosis, histopathological