Abstract
Outbreaks of scale protrusion disease in carp fishes are frequently observed at fish farms in Japan. Characteristics of a aeromonas isolated from all cases of diseased fish in freshwater were determined as well as ability of bacterium to produce experimental infection. The organism was Gram-negative rods. actively motile by means of a single polar flagellum, which showed some pleomorphism (Fig. 5, 6, 7). The bacilli occurred singly or in pairs and some had rounded ends. Catalase and oxidase, glucose fermented and gas produced, arginine dehydrolase produced (Table 3, 4, 5). On these findings the organism was identified as Aeromonas liquefaciens.
