Meta-Transcriptomic Analysis Reveals Novel RNA Viruses in Polychaetes Perinereis .

Perinereis species are essential benthonic animals in coastal ecosystems and have significant roles as live feed in aquaculture, owing to their high-protein and low-fat nutritional profile. Despite their ecological importance, the viral communities associated with these organisms need to be better understood. In this study, we generated 2.6 × 10 8 reads using meta-transcriptomic sequencing and de novo assembled 5.3 × 10 3 virus-associated contigs. We identified 12 novel RNA viruses from two species, Perinereis aibuhitensis and P. wilsoni , which were classified into four major viral groups: Picobirnaviridae , Marnaviridae , unclassified Picornavirales , and unclassified Bunyavirales . Our findings revealed the hidden diversity of viruses and genome structures in Perinereis , enriching the RNA virosphere and expanding the host range of Picobirnaviridae, Marnaviridae , and Bunyavirales . This study also highlighted the potential biosecurity risk of the novel viruses carried by Perinereis to aquaculture.