the morbid/moribund fish were removed and necrop sied for determination of internal lesioas and re-isolation of a hydrophila form the kidney or gill. to recover the bacteria, a loop of aseptically piercing specimen form the kidney or a piece of gill filament was inoculated on 5% sheep blood agar (SBA) and MacConkey agar (McA) and incubated at 37 for 16-24 hr. single aeromonas-like colony was sulyected for gram's staining and re-cultured in BHI to subsequently identify by a procedure as mentioned above