Amoebic gill disease (AGD) is a potentially fatal disease of some marine fish. It is caused by Neoparamoeba perurans, the most important amoeba in cultured fish. It primarily affects farm raised fish of the family Salmonidae, most notably affecting the Tasmanian Atlantic salmon (Salmo salar) industry, costing the A$20 million a year in treatments and lost productivity. Turbot, bass, bream, sea urchins and crabs have also been infected.