Données sur le nouveau parasite de l'huître plate. Situation épidémiologique

Abnormal mortalities of flat oysters, Ostrea edulis, have been monitored in June 1979 in some farms of l'Ile Tudy. The examination of these oysters with light and electron microscopy showed different forms of an intracellular parasite localized in the connective tissue of the gills and the digestive gland. It is also detectable in the blood vessels and the stomachal epithelium. Numerous parasited oysters showed distinctive branchial damages (perforations, indentations) visible through macroscopic examination. The epidemiological monitoring carried out on the Norman and Breton coast revealed the presence of this parasite in a large number of flat oyster farms. The percentage of parasited oysters is higher in areas where mortalities have been monitored but the parasite's pathogenic role could not be determined yet. Its taxonomic position has not been defined.