Electron Microscopy on the Heart of Kuruma Prawn Penaeus japonicus Artificially Infected with Penaeid Rod-shaped DNA Virus

Penaeid acute viremia (PAV) or white spot disease (WSD) causes mass mortality in cultured penaeid shrimp. Despite many histopathological studies, the principal lesion in the diseased shrimp remained unclear. Here we reevaluated the histopathology and ultrastructure of moribund kuruma prawn Penaeus japonicus artificially infected with penaeid rod-shaped DNA virus (PRDV) as a pathogen of PAV. We showed that PRDV infected cardiac satellite cells, primary myocardial cells and myocardial cells of the heart, where the nuclei of these cells displayed virus propagation that resulted in severe myocardial necrosis. Myocardial necrosis was suggested to be a primary cause of the viremia of PAV.