AN IRIDOVIRUS-LIKE AGENT ASSOCIATED WITH SYSTEMIC INFECTION IN CULTURED TURBOT SCOPHTHALMUS-MAXIMUS FRY IN DENMARK

A disease in a Danish turbot Scophthalmus maximus rearing unit caused the death of approximately 50 000 fry corresponding to a mortality of 70 %. The initial signs of disease were reduced feed intake, lethargy and darkening in pigmentation, especially of the tail and fins. Later there was atypical swimming, e.g. swimming on edge, and spasms in the terminal stages. An iridovirus-like agent, measuring ca 170 nm in diam eter (160 to 185 nm), was detected by electron microscopy in samples o f fin, gill, liver, kidney, spleen, heart, pancreas, intestinal collag en, and in 1 of 3 brain samples examined. After decontamination of the facilities, no new outbreaks have occurred.