Is a virus infecting populations of tilapia, a fish belonging to the family Cichlidae. Has been identified and recovered from episodes of massive mortalities of wild and pond-cultured tilapia all over Israel. Is a RNA virus distantly related to the Influenza C virus and is likely a novel orthomyxovirus. Reported symptoms of infected fish include reddened skin, inflammation of organs including the eyes and brain, liver damage, and eventual organ failure and death. The mortality rate is about 80-100% of infected fish.