Hidden diversity and evolution of viruses in market fish. Issue 2 (31st October 2018)

• Record Type: Journal Article
• Authors: Geoghegan, Jemma L; Di Giallonardo, Francesca; Cousins, Kate; Shi, Mang; Williamson, Jane E; Holmes, Edward C
• Is Part Of: Virus evolution. Volume 4:Issue 2(2018)
• Publication Date: 2018-10-31
• Subjects: fish -- virome -- meta-transcriptomics -- virus evolution -- phylogenetics; Viruses -- Evolution -- Periodicals; 579.2138
• DOI: 10.1093/ve/vey031
• Languages: English
• ISSNs: 2057-1577

Abstract

Abstract: Aquaculture is the fastest growing industry worldwide. Aquatic diseases have had enormous economic and environmental impacts in the recent past and the emergence of new aquatic pathogens, particularly viruses, poses a continuous threat. Nevertheless, little is known about the diversity, abundance and evolution of fish viruses. We used a meta-transcriptomic approach to help determine the virome of seemingly healthy fish sold at a market in Sydney, Australia. Specifically, by identifying and quantifying virus transcripts we aimed to determine (i) the abundance of viruses in market fish, (ii) test a key component of epidemiological theory that large and dense host populations harbour a greater number of viruses compared to their more solitary counterparts and (iii) reveal the relative roles of virus–host co-divergence and cross-species transmission in the evolution of fish viruses. The species studied comprised both shoaling fish—eastern sea garfish ( Hyporhamphus australis ) and Australasian snapper ( Chrysophrys auratus )—and more solitary fish—eastern red scorpionfish ( Scorpaena jacksoniensis ) and largetooth flounder ( Pseudorhombus arsius ). Our analysis identified twelve potentially novel viruses, eight of which were likely vertebrate-associated across four viral families and that exhibited frequent cross-species transmission. Notably, the most solitary of the fish species studied, the largetooth flounder, harboured the least number of viruses while eastern sea garfish, a densely shoaling fish, had the highest number of viruses. These results support the emerging view that fish harbour a large and largely uncharacterised virome.