the morbid/moribund fish were removed and necropsied 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