[2][3] It is substantially larger than coronaviruses, another group of nidoviruses known for large genomes, which are typically in the 27–32 kb range.

However, the ExoN structure and active site residues are divergent from other nidoviral examples, and the 3CL-like protease appears to use a serine–histidine–aspartate catalytic triad, in contrast to the cysteine nucleophile typical of other nidoviruses.

[2] Uniquely among known nidoviruses, PSCNV also encodes several other identifiable protein domains, possibly acquired from the host.

[2] PSCNV has been shown experimentally to infect the secretory cells of planarians of the species Schmidtea mediterranea, including both asexually reproducing and sexual strains.

It appears to be present in multiple such transcriptome datasets, suggesting that infection of laboratory S. mediterranea is common, especially in sexual strains.