2019 Volume 54 Issue 3 Pages 61-63
Experimental infection trials of six riverine fish species with Edwardsiella ictaluri were performed using an immersion method at three water temperatures, 20°C, 25°C, and 30°C. At 20°C, mortalities were recorded only in ayu Plecoglossus altivelis and amur catfish Silurus asotus. Whereas, at 25°C or 30°C, mortality events occurred in other species including Japanese dace Tribilodon hakonensis, gibachi Tachysurus tokiensis, and Japanese eel Anguilla japonica, except for common carp Cyprinus carpio, and high (≥80%) cumulative mortalities were recorded in ayu, amur catfish, and gibachi. These results suggest that many riverine fishes are at risk of E. ictaluri infection during periods of high water temperature.