First record of Perkinsus chesapeaki infecting Crassostrea rhizophorae in South America.

This study investigated Perkinsus spp. infecting Crassostrea rhizophorae from the Jaguaribe River estuary, Ceará, Brazil. Fragments of gills and rectum of the oysters (n=150) were incubated in Ray's fluid thioglycollate medium (RFTM). Genus Perkinsus-specific PerkITS85/750 PCR assays were performed and their amplicons were sequenced by the Sanger method. The RFTM assays confirmed Perkinsus spp. The sequencing of the amplified fragments from the rDNA internal transcribed spacers (ITS) of Perkinsus spp. confirmed Perkinsus chesapeaki. Neighbor-Joining analyzes place P. chesapeaki identified in this study in a well-supported clade with other isolates of the same species. This is the first record of P. chesapeaki infecting C. rhizophorae in South America.