Family: Nipumfusiviridae

Genus: Marefusivirus

Distinguishing features

The genus Marefusivirus (family: Nipumfusiviridae) includes five species (Marefusivirus columbiaense, Marefusivirus helgoense, Marefusivirus jervisense, Marefusivirus montereyense, and Marefusivirus pacificense). Viruses in these species were all discovered via metagenomic analysis of marine samples. Their distribution across diverse marine zones implies potential infection of ubiquitous marine Nitrosopumilaceae archaea. Viruses assigned to the genus must demonstrate: (I) ≥50% mean amino acid identity in all pairwise ortholog comparisons with established genus members and (II) conservation of the major capsid protein and ATPase.

Demarcation criteria for taxa within the genus

For classification as a distinct species, novel members must show ≤95% average nucleotide identity in pairwise comparisons with members of established species of the genus.