The pathogenicity of Aeromonas salmonicida (Griffin) in sea and brackish waters.

The experimental pathogenesis of Aeromonas salmonicida for the sea trout (Salmo trutta) and the brown trout (Salmo fario) in sea and brackish waters was examined by contact between infected and healthy fishes. Sea trout and brown trout both acquired infection by contact with infected S. fario at salinity values from 2-54 yo to 3.3 I yo (wlw) when water temperatures ranged from 5.6" to 14.5". The species differed in their resistance to infection. About 90% of the sea trout became infected and died within 7 days, developing superficial lesions typical of the disease. The brown trout appeared to be more resistant, about 75% developing and dying from an atypical form of the disease.