Viral families (VFAMs, x axis) in species (y axis) from each of the three phyla. VFAMs were hierarchically bi-clustered using average Euclidean distance; theZscore correlates with relative VFAM counts. A cluster of VFAMs mostly unique to phaeophyte algae are shown in the dashed line box. These VFAMs are also found in viruses infecting Rhodophyta and Chlorophyta algae, which hints at cross-phyla infection; however, these specific VFAMs were not in the Rhodophyta or Chlorophyta algal genomes.
