Cypriniviruses largely affect common and koi carp (Cyprinus carpio), goldsh (Carassius auratus), Prussian carp (Carassius gibelio), and crucian carp (Carassius carassius). In particular, cyprinid herpesviruses 1 (CyHV-1) and 3 (CyHV-3) are important pathogens of C. carpio, while CyHV-2 affects C. auratus, C. gibelio, and C. carassius. These host species belong to the family Cyprinidae, the largest family of freshwater shes in the world with over 2000 species in 210 genera.1 Native species occur in all tropical and temperate regions except Australia, New Zealand, Madagascar, and South America. However, cyprinids have even been introduced to each of these previously free locations. While common carp are an important food source for humans in Asia, Europe, and Israel,2 koi carp and goldsh are almost purely ornamental sh, albeit sometimes being very expensive. By contrast, in many regions of the world (e.g., Australasia and North America), carp are regarded as an environmental pest species.3