White spot syndrome virus is the lone virus (and type species) of the genus Whispovirus (white spot), which is the only genus in the family Nimaviridae. It is responsible for causing white spot syndrome in a wide range of crustacean hosts. White spot syndrome (WSS) is a viral infection of penaeid shrimp. The disease is highly lethal and contagious, killing shrimps quickly. Outbreaks of this disease have wiped out within a few days the entire populations of many shrimp farms throughout the world.