Survey of viral and bacterial pathogens in ornamental aquatic crustaceans imported into South Korea

The annual rate of ornamental aquatic crustacean importation is increasing globally. The continuous high demand for live ornamental aquatic crustaceans in many countries has also increased the frequency of imported exotic pathogens, which has caused many problems. In the present study, we examined the monthly distribution of viral and bacterial pathogen genes in ornamental aquatic crustaceans imported into South Korea during a 6-month period from February to July 2016. Among the bacterial pathogens identified, Vibrio alginolyticus was detected in cleaner shrimp in June, and Photobacterium damselae was detected in cleaner shrimp in July. Vibrio penaeicida was detected in peppermint shrimp, banded coral shrimp, hinge-beak shrimp, and orange swamp crayfish between February and June. Among the viral pathogens identified, spawner mortality virus was detected in cherry shrimp in May. Finally, hepatopancreatic parvovirus was detected in both cherry shrimp and orange swamp crayfish between February and March. Notably, the genes of two viral pathogens were also detected in cherry shrimp. Although the viruses were not isolated, they are very likely to have been introduced into South Korea and have an influence on Korean aquaculture. In South Korea, HPV is already prevalent and has been reported several times in aquaculture and in the wild; however, SMV infection has not been reported to date. These results demonstrate that many bacterial and viral pathogens are regularly introduced into South Korea via the ornamental aquatic-crustacean trade.