Abstract
The results of a taxonomical study of 50 Vibrio strains isolated from several fishes diseased; yellowtail (Seriola quinqueradiata), kampachi (Seriora purpurascens), red sea bream (Chrysophrys major), black sea bream (Mylio macrocephalus), amago (Oncorhynchus rhodurus f. macrostomus), ayu (Plecoglossus altivelis) and eel (Anguilla japonica), and allied reference 21 strains show that the fish pathogenic vibrios can be divided into three major groups.
Group I, Vibrio anguillarum are also subdivided into three subgroups according to their source, whether host fish have been affected in sea water, estuarine water or fresh water.
Group II including Vibrio sp. K-3 have a close relationship to Vibrio parahaemolyticus, but are distinguishable from group I, V. anguillarum.
Group III isolated almost from red sea bream in winter, seem to be pathogenic in the season of low water temperature, and in connection with V. ichthyodermis.
Comparing some characteristic features of each group, a diagnostic scheme useful for rapid identification is given.
