Faecal Viromes of Three Sympatric Penguins on Ardley Island, Antarctica: A Transcriptomic Study Showing Limited Host-Species Effect

During the 41st Chinese Antarctic Expedition (2024–2025), fresh faecal samples were collected from sympatric Adélie, chinstrap, and gentoo penguins on Ardley Island. The faecal viromes were systematically profiled via transcriptomic sequencing coupled with viral contig assembly. Thirty-two known viral families were annotated, yet over half of viral reads remained unclassified, indicating substantial uncharacterised viral diversity in Antarctic penguin guts. No significant interspecific differences in viral abundance or alpha-diversity were detected, and host-species exerted only a weak effect on viral community structure. While H5N1 highly pathogenic avian influenza and Newcastle disease virus were absent, several potential pathogens, including deltacoronaviruses, novel astroviruses, and picornaviruses, were recovered. This work establishes baseline virome data for Antarctic pygoscelid penguins and provides valuable insights for long-term pathogen surveillance of polar wildlife and assessments of viral spillover risk.