Resistance of Black-lip learl oyster, Pinctada margaritifera, to infection by Ostreid herpes virus 1μvar under experimental challenge may be mediated by humoral antiviral activity.

Ostreid herpesvirus 1 (OsHV-1) has induced mass mortalities of the larvae and spat of Pacific oysters, Crassostrea gigas, in Europe and, more recently, in Oceania. The production of pearls from the Black-lip pearl oyster, Pinctada margaritifera, represents the second largest source of income to the economies of French Polynesia and many Pacific Island nations that could be severely compromised in the event of a disease outbreak. Coincidentally with the occurrence of OsHV-1 in the southern hemisphere, C.

[Presence of gregarine (Protozoa sporozoa) parasite of black-lipped pearl oysters Pinctada margaritifera (L.,1758) (Mollusca bivalvia) in French Polynesia].

High death rates have been recorded in populations of Pinctada margaritifera (natural or reared stocks) in atolls in the Tuamotu Archipelago (French Polynesia). An histological study of the oysters from the concerned areas revealed the occurrence of a protist of which ultrastructural features correspond to those of Gregarinea. It is still premature to establish a link between the presence of the Gregarine and recent deaths of pearl oysters.