Wikipedia
Megalocytivirus
Megalocytivirus is one of five genera of viruses within the family Iridoviridae and one of three genera within this family which infect teleost fishes, along with Lymphocystivirus and Ranavirus. The megalocytiviruses are an emerging group of closely related dsDNA viruses which cause systemic infections in a wide variety of wild and cultured fresh and saltwater fishes. Megalocytivirus outbreaks are of considerable economic importance in aquaculture, as epizootics can result in moderate fish loss or mass mortality events of cultured fishes.