Amphipoda and the Riboviria: viral diversity on a global scale

RNA viruses are the most abundant group of pathogens on the planet; however, little is known about their association with amphipods (Crustacea: Peracarida). Here, we explore RNA virus diversity across invasive and native amphipod species inhabiting freshwater, marine, brackish and terrestrial environments around the globe, and analyse this data in relation to host invasion status, environment type, and between host taxa. We sampled tissue from 8 amphipod populations and screened an additional 152 from NCBI for RNA viruses. In total, 412 viral contigs were recovered, including 134 novel virus species, 41 with complete genomes. Viral contigs were associated with the: Articulavirales (n = 35); Bunyavirales (n = 38); Durnavirales (n = 6); Ghabrivirales (n = 28); Hepelivirales (n = 43); Jingchuvirales (n = 16); Martellivirales (n = 4); Mononegavirales (n = 139); Nidovirales (n = 1); Nodamuvirales (n = 2); Picornavirales (n = 97); Wolframvirales (n = 3). The alpha diversity of RNA viruses significantly differed between environments (freshwater, marine, and brackish) and amphipod host species. Host invasion status was not a significant driver in viral diversity. β diversity analysis revealed no significant difference in multivariate dispersion between environments, suggesting that freshwater, marine and terrestrial environments are equally rich in amphipod virus diversity; however, environment did have a significant effect on the viral community composition. This study contributes to our view of viral evolution and diversification among the Crustacea and boosts our understanding of RNA virus diversity and host range associated with invasion ecology and disease ecology within benthic communities.