Aeromonas hydrophila Versus Edwardsiella tarda A Pathoanatomical Study in Clarias batrachus

Asian catfish, Clarias batrachus intramuscularly injected with Aeromonas hydrophila and Edwardsiella tarda were examined for gross and histopathological changes in various organs. A. hydrophila infected fish developed white necrotic ulcers at the injected site after 4 days along with patchy haemorrhagic ulcerative areas on posterior part of the body, tail and caudal fin behind the injected sites. The mortality was marked 5th day onwards. Whereas E. tarda injected fish revealed red round haemorrhagic ulcers on 2nd day at the site of injection which became necrotic on 3rd day. The mortality started from 2nd day onwards. The organs from moribund and freshly dead fish were collected and histopathological alterations caused by both the pathogens were studied.