Genetic diversity of the Caribbean spiny lobster virus, Panulirus argus virus 1 (PaV1), and the ­discovery of PaV1 in lobster postlarvae

Panulirus argus virus 1 (PaV1) is an unclassified, pathogenic virus first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys, USA, and has since been con- firmed in lobsters in other parts of the Caribbean. Several studies have examined the prevalence, pathogenicity, and population dynamics of the pathogen in the lobster host, but little is known about the genetic diversity of the virus. We analyzed a fragment of viral DNA from lobsters col- lected in the Florida Keys, which provided the first insight into the genetic diversity of PaV1. The variation in viral sequences, both within and between individual lobsters, indicates that lobsters can be infected with multiple viral strains. Laboratory experiments in which uninfected lobsters were serially exposed to lobsters inoculated with PaV1 implied that rapid mutation of strains is unlikely and suggest that there may be endemic strains of PaV1. In addition, we discovered PaV1 in P. argus postlarvae (pueruli), suggesting that the virus may disperse through the Caribbean within the long-lived (5 to 7 mo) planktonic phyllosoma larvae — a novel mechanism for dispersal of viruses in the sea.