Presence of Bonamia ostreae among populations of the European flat oyster, Ostrea edulis Linne, in California, USA.
Friedman, C. S., McDowell, T., Groff, J. M., Hollibaugh, J. T., Manzer, D. and Hedrick, R. P.
J. Shellfish Res.
European Flat oysters, Ostrea edulis, reared in Tomales Bay and the Santa Barbara Channel, California were examined to determine the possible causes of elevated mortality among these stocks. The protozoan parasite, Bonamia ostreae was found to be the most significant parasite in these oysters. A rickettsiales-like and a gregarine-like parasite were seen within gill tissues of a flat oyster and one bay mussel, respectively. B. ostreae elicited an intense inflammatory reaction in affected flat oysters and is believed to be the cause of the elevated mortality observed in these stocks.