2021 Volume 56 Issue 1 Pages 14-17
In August 2017, a mass mortality of cultured ayu Plecoglossus altivelis occurred in Hiroshima Prefecture. Most of the diseased fish showed hemorrhagic and swelling lesions on the body surface. Bacterial isolates from diseased ayu were identified as Aeromonas hydrophila by conventional characterization tests and genetic analysis. However, the clinical signs differed from previously reported A. hydrophila infection in ayu. The present isolate caused higher mortality in ayu without clinical signs at 24°C than at 19°C. These results indicate that the present mass mortality was caused by A. hydrophila and the pathogenicity of the isolates was related to water temperature.
