A Novel Rubi-Like Virus in the Pacific Electric Ray () Reveals the Complex Evolutionary History of the .

(RuV) is the causative agent of rubella ("German measles") and remains a global health concern. Until recently, RuV was the only known member of the genus and the only virus species classified within the family of positive-sense RNA viruses. Recently, two new rubella-like matonaviruses, and , have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses, we mined published transcriptome data using genome sequences from , , and as baits. From this, we identified a novel rubella-like virus in a transcriptome of -order Torpediniformes (Pacific electric ray)-that is more closely related to mammalian than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific electric ray, and two other viruses identified in this animal, from the and , grouped with other fish viruses. These findings indicate that the evolutionary history of the is more complex than previously thought and highlights the vast number of viruses that remain undiscovered.