Detection and persistence of Lymphocystis disease virus (LCDV) in Artemia sp

Lymphocystis disease virus (LCDV) was detected by PCR-hybridisation in Artemia cysts and metanauplii, and the infectivity of these viral particles was confirmed by inoculation on SAF-1 cells. Viral genome and antigens have been detected by whole-mount in situ hybridisation (ISH) and immunofluorescence assay (IFA) in the digestive tract of nauplii hatched from LCDV-contaminated cysts, but not at the umbrella and instar I stages. Instar II nauplii also became LCDV-contaminated after bath challenge. LCDV was detected by ISH and immunohistochemistry (IHC) in the digestive tract and in some cells in the ovisac of adults reared from LCDV-positive instar II nauplii. Reproductive cysts arising from LCDV-contaminated Artemia breeders, as well as their offspring nauplii, were also LCDV-positive. No viral genome and antigens were detected in the eggs, which may indicate an external cyst contamination during spawning. Moreover, viral DNA on cysts disappears by the decapsulation treatment, which may be applied to prevent the transmission of LCDV in Artemia. Infective LCDV particles persist along crustacean life cycle, as demonstrated by cell culture. These findings suggest that Artemia might act as a reservoir of LCDV, although further studies are necessary to establish its role as a vector of this virus to cultured fish.