Aquareovirus is a genus of viruses, in the family Reoviridae, in the subfamily Spinareovirinae. Fish, shellfish, and crustacean species serve as natural hosts. There are currently seven species in this genus including the type species Aquareovirus A. In general, Aquareoviruses have low or no pathogenicity for fish. However, some cause hemorrhagic disease, hepatitis and pancreatitis. Grass carp hemorrhage virus (causes hemorrhagic disease of grass carp) is the most pathogenic Aquareovirus. Group: dsRNA Viruses in Aquareovirus are non-enveloped, with icosahedral geometries, and T=13, T=2 symmetry. The diameter is around 75 nm. Genomes are linear and segmented, around 4.0kb in length. The genome codes for 12 proteins. Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Replication follows the double-stranded RNA virus replication model. Double-stranded rna virus transcription is the method of transcription. The virus exits the host cell by monopartite non-tubule guided viral movement.Fish, shellfish, and crustacean species serve as the natural host.