Abstract
Pathogenicity of a marine birnavirus (AY-98) isolated from diseased ayu Plecoglossus altivelis was investigated. Cumulative mortalities in the intraperitoneally injected groups of ayu in two weeks were 70% (dose 105.4 TCID50/fish) -71% (105.8 TCID50/fish) in duplicated experiments. Histologically, the naturally and experimentally infected fish showed brain congestion and pancreatic necrosis. From the symptoms of body deformity and congestion in the brain, it was thought that AY-98 is similar to viral deformity virus, the birnavirus isolated from yellow tail Seriala quinqueradiata with deformity.
