NEOPLASTIC DISEASE IN BIVALVE MOLLUSKS FROM OREGON ESTUARIES WITH EMPHASIS ON RESEARCH ON PROLIFERATIVE DISORDERS IN YAQUINA BAY OYSTERS*

Abstract

Studies were conducted on oysters (Ostrea lurida) in Yaquina Bay, Oregon, to determine seasonal effects on proliferative disorders, correlation between onset of the condition and age of oysters, and the exact nature of the proliferative disorders. Imported oysters were planted at various locations; the mortality was monitored and monthly histological examinations were made. Results indicated that the disorders did not occur in significant numbers of oysters. There were occasional, small, late-summer oyster mortalities associated with increased water temperature and blooms of Vibrio bacteria. There was no definitive evidence to indicate whether the proliferative disorder caused mortality of the affected oysters. (HLW)