Award: OCE-1049670

The major goal of this EAGER award was to identify viruses in copepods, the most abundant mesozooplankton group. We have successfully accomplished the goals of this project by discovering two novel circoviruses in the calanoid copepods Acartia tonsa (AtCopCV) and Labidocera aestiva (LaCopCV), and demonstrating the high prevalence and viral load of these viruses. In addition, we documented the presence of viral particles in copepod tissues by transmission electron microscopy (TEM). Together, these genomic and microscopic results represent two independent lines of evidence for viral infection in natural populations of marine copepods. LaCopCV and AtCopCV are the first viruses discovered in any marine mesozooplankton, as well as the first circoviruses described in a marine host. In addition, these genomes suggest that mesozooplankton may be a potential source for the novel circovirus genome architectures identified in marine virioplankton through metagenomics (Rosario et al. 2009; Rosario et al. 2012). Through this project we also discovered circoviruses in several decapod crustaceans, including Farfantepenaeus duorarum and Diporeia spp., and found that copepod-associated circoviruses are widely distributed in net plankton from coastal marine habitats. By demonstrating that viruses infect ecologically important copepod species at high prevalence and viral loads, we have set the stage for future work to examine the geographic range, transmission mechanisms, and ecological impacts of viruses on copepods. Last Modified: 10/31/2013 Submitted by: Ian Hewson