Genus: Bacillarnavirus

Genus: Bacillarnavirus

Distinguishing features

Members of the genus form a separate clade from other members of the family upon phylogenetic analysis of RNA-directed RNA polymerase amino acid sequences.


See discussion under family description

Genome organization and replication

The current members of the genus have di-cistronic genomes (Figure 2.Marnaviridae). See discussion under family description.


See discussion under family description.

Species demarcation criteria

Species demarcation cut-offs are based on pairwise comparisons of the RdRP and capsid amino acid sequences. The cut-offs are 90% identity for the RdRP and 75% identity for the capsid. The phylogenetic relationship of classified virus isolates and numerous unclassified viruses is shown in Figure 1.Bacillarnavirus.

Figure 1.Bacillarnavirus. Maximum likelihood tree of bacillarnavirus RdRP amino sequences. The tree was produced using the JTT model with a gamma distribution of frequencies and invariant sites. Bootstrap values are shown where they were over 70%. Tips are labelled with filled circles for members of species; open circles represent unclassified viruses. Heterosigma akashiwo RNA virus (AY337486) was used as an outgroup. This phylogenetic tree and corresponding sequence alignment are available to download from the Resources page.

Member species

Exemplar isolate of the species
SpeciesVirus nameIsolateAccession numberRefSeq numberAvailable sequenceVirus Abbrev.
Chaetoceros socialis forma radians RNA virus 1Chaetoceros socialis f. radians RNA virus 01Hiroshima BayAB469874NC_012212Complete genomeCsfrRNAV01
Chaetoceros tenuissimus RNA virus 01Chaetoceros tenuissimus RNA virus 01Seto Inland SeaAB375474NC_038321Complete genomeCtenRNAV01
Rhizosolenia setigera RNA virus 01Rhizosolenia setigera RNA virus 01RsRNAV06AB243297NC_018613Complete genomeRsRNAV01

Virus names, the choice of exemplar isolates, and virus abbreviations, are not official ICTV designations.

Related, unclassified viruses

Virus name

Accession number

Beihai picorna-like virus 24


Beihai picorna-like virus 25


Beihai picorna-like virus 26


Beihai picorna-like virus 27


Beihai picorna-like virus 28


N OV 003


Virus names and virus abbreviations are not official ICTV designations.