Parvoviruses of Aquatic Animals

Family Parvoviridae consists of small, non-enveloped viruses with linear, single-stranded DNA genomes of approximately 4-6 kilobases, subdivided into 3 subfamilies: Parvovirinae, Densovirinae and Hamaparvovirinae. Parvoviruses of aquatic animals infect crustaceans, mollusks, and finfish. In this review, these parvoviruses, which are highly host-specific and are associated with mass morbidity and mortality in both farmed and wild aquatic animals are described. They include Cherax quadricarinatus densovirus (CqDV) in freshwater crayfish; Sea star-associated densovirus (SSaDV) in sunflower sea star on the Northeastern Pacific Coast; Clinch densovirus 1 in freshwater mussels in the Clinch River, Virginia, and Tennessee, USA, in subfamily Densovirinae; Hepatopancreatic parvovirus (HPV) and Infectious hypodermal and hematopoietic necrosis virus (IHHNV) in farmed shrimp worldwide; Syngnathid ichthamaparvovirus 1 in gulf pipefish in the Gulf of Mexico and parts of South America; and Tilapia parvovirus (TiPV) in farmed tilapia in China and Thailand, in the subfamily Hamaparvovirinae. In addition, virus megataxonomy has enabled the inclusion of novel parvoviruses detected in both diseased and healthy animals using metagenomic sequencing for virus discovery, such as the novel zander parvovirus from zander in Hungary, novel salmon parvovirus from sockeye salmon smolts in British Columbia-Canada, and Spawner-isolated mortality virus (SMV) from shrimp broodstock in Australia.