Since only one genus is currently recognized, the genus description corresponds to the family description.
Species demarcation criteria
The different criteria considered for species demarcation in the genus are:
- differences in coat protein (CP) mass
- serological relationship between CPs
- differences in natural host range
- different number, organization and/or size of genome segments.
Alignments between citrus psorosis virus, freesia sneak virus, Mirafiori lettuce big-vein virus, lettuce ring necrosis virus, blueberry mosaic associated virus and ranunculus white mottle virus (partial sequence) CP amino acid sequences show 31–52% identity, whereas isolates of the same species show over 92% identity. Since CPs of Mirafiori lettuce big-vein virus and tulip mild mottle mosaic virus (partial cds) share about 80% amino acid sequence identity, this may warrant the establishment of the following molecular criterion for ophiovirus species demarcation: CP amino acid sequence identity <85%.