Abstract
From June to October in 1980, mortalities occurred among the cultured Japanese horse mackerel (Trachurus japonicus) in Tachibana Bay, Nagasaki Prefecture. The typical external symptom of the diseased fish was corneal opacity and reddening of the eye-ball which finally progressed to evulsion of the orbital contents. A bacterium was isolated from the eye, liver, kidney, etc. of all the diseased fish. By inoculation experiments the bacterium was proved to be pathogenic to Japanese horse mackerel. The bacterium was placed in the genus Vibrio from its biological and biochemical characteristics.
Although the biochemical and biological characters of the isolates resembled closely to those of Vibrio parahaemolyticus, they could be distinguished from V. parahaemolyticus by its lower NaCl and temperature tolerance.
As above mentioned this bacterium may be regarded as a new fish pathogenic vibrio in the future.
