Fish viruses: transmission and pathogenicity of an icosahedral cytoplasmic deoxyribovirus isolated from sheatfish (Silurus glanis).

An iridovirus-like agent which was isolated from sheatfish fry showed to be of high virulence to those fish. 100% of sheatfish fry infected by water bath died within 8 days. The agent could be transmitted by infected fish causing 100% mortality in 11 days. Moribund fry showed spiralic swimming and exhibited hemorrhages in the skin. The infection studies demonstrate that the isolated virus was responsible for a sudden epizootic in 1988 with 100% mortality occurring in a warm water recirculating aquaculture unit in Northwest Germany, regularly controlled by the State Fish Epidemics Control Service of Lower Saxony and Fish Health Service.