Detection of cyprinid herpesvirus-3 DNA in lake plankton.

The disease caused by cyprinid herpesvirus-3 (CyHV-3) severely impacts the natural freshwater ecosystem and damages carp and koi farming, however, the pathway of CyHV-3 transmission remains unclear. It is possible that the virus adheres to plankton, which then facilitate viral movement and transmission, and therefore, it is hypothesised that plankton are involved in the disease dynamics. In this study, plankton were collected at eight sites in the Iba-naiko lagoon; we detected and quantified CyHV-3 DNA from plankton samples. The results of the correlation analysis showed a significant positive correlation between CyHV-3 copies and the number of Rotifera, suggesting that CyHV-3 binds to and/or is concentrated by Rotifera. Our results suggest that plankton affect viral ecology in the natural environment.