New records of the non-indigenous oyster Saccostrea cucullata (Bivalvia: Ostreidae) from the southeast and south Brazilian coast

New records of the non-indigenous species of oyster, Saccostrea cucullata were found along the southeast and south coasts of Brazil. Previously, the only documented record in the southwestern Atlantic Ocean was known from Bertioga, São Paulo State (Southeast Brazilian coast). We updated the known distribution of this species to include the states of Rio de Janeiro, Paraná and Santa Catarina, and new localities in the state of São Paulo. Studied samples were found attached to natural (mangrove roots, rocky shores, rocky reefs and gravels) and artificial (harbor, marina and jetty) substrates, forming clusters of many individuals and cohabiting with native oyster species (Crassostrea mangle, C. brasiliana and Ostrea puelchana). Recent introduction of marine organisms has been common in coastal waters due to ballast water, aquaculture activities and ship hull incrustation. Considering the high connectivity of shipping especially in port areas, like Santos (SP), Paranaguá (PR) and Tubarão (SC), Saccostrea may have been introduced to the Brazilian coast by either recreational or commercial vessels, probably between the years 2005 and 2014.