Perkinsus sp. infecting oyster Crassostrea rhizophorae (Guilding, 1828) on the coast of Bahia, Brazil

Abstract This study investigated the occurrence of the protozoan Perkinsus in the oyster Crassostrea rhizophorae on the coast of Bahia State, Brazil. The oysters ( n  = 900) were collected in February–March and July–August 2010. The Ray’s fluid thioglycollate medium (RFTM) analysis of gills and rectum revealed hypnospores of Perkinsus sp. with a high mean prevalence (63%). The infection intensity varied from very light to advanced. The polymerase chain reaction confirmed Perkinsus in 87.2% of the RFTM-positive oysters. Histological analysis showed trophozoites and schizonts phagocytized by hemocytes, mainly in the intestine and the stomach epithelium.