Regional Studies in Marine Science 33 (2020) 100924 Contents lists available at ScienceDirect Regional Studies in Marine Science journal homepage: www.elsevier.com/locate/rsma New records of the non-indigenous oyster Saccostrea cucullata (Bivalvia: Ostreidae) from the southeast and south Brazilian coast Vanessa Simão do Amaral a , Luiz Ricardo L. Simone b , Frederico Tapajós de Souza Tâmega c,d,∗ , Edison Barbieri e , Sávio Henrique Calazans d , Ricardo Coutinho d , Paula Spotorno-Oliveira c,d a Universidade Federal do Espírito Santo – UFES/Centro Universitário do Norte do Espírito Santo – CEUNES, 29932-540, São Mateus, ES, Brazil b Museu de Zoologia da Universidade de São Paulo, CP 42494, 04299–970, São Paulo, SP, Brazil c Programa de Pós-Graduação em Oceanologia, Instituto de Oceanografia, Universidade Federal do Rio Grande – FURG, Av. Itália Km 8, 96203–900, Rio Grande, RS, Brazil d Instituto de Estudos do Mar Almirante Paulo Moreira, 28930–000, Arraial do Cabo, RJ, Brazil e Instituto de Pesca-APTA-SAA-Governo do Estado de São Paulo, SP, Brazil article info Article history: Received 1 April 2019 Received in revised form 2 November 2019 Accepted 2 November 2019 Available online 6 November 2019 Keywords: Invasive species Ostreidae Brazil abstract 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. © 2019 Elsevier B.V. All rights reserved. 1. Introduction The expansion of maritime traffic with larger and faster vessels allowed the reduction of travel time and the intensification of international trade, as a consequence, in 2017 the world’s com- mercial shipping fleet consisted of approximately 93,000 vessels and was responsible for over 80% of global trade (UNCTAD et al., 2017). Factors associated with maritime transport are ballast water and fouling on the ship hulls, which are extremely efficient mechanisms in the dispersion of exotic marine organisms (Silva and Souza, 2004), mainly in tropical environment. Species of Saccostrea Dollfuss and Dautzenberg, 1920 are com- mon oysters that live on rocky shores of the Indo–Pacific region (Lam and Morton, 2006). The taxonomy of this genus, as normally occurs in ostreids, is unclear, as the morphological plasticity makes identification problematic (Lam and Morton, 2006). Their ∗ Corresponding author at: Programa de Pós-Graduação em Oceanologia, Instituto de Oceanografia, Universidade Federal do Rio Grande – FURG, Av. Itália Km 8, 96203–900, Rio Grande, RS, Brazil. E-mail address: fredtamega@gmail.com (F.T.S. Tâmega). shells have to 100 mm length, a left valve with a prominent ligamentary area showing clearly and continuous regular primes. The right valve is flat, bearing projections along its margin, with corresponding concavities on the left valve. Samples of the genus have been studied as part of a project that deals with the taxon- omy and morphology of the ostreids (Amaral, 2010, 2014; Amaral and Simone, 2014, 2016). Salinity and temperature of seawater seem to be the two leading factors controlling the spawning of oysters. It largely inhabits the brackish water area and is found attached in clusters to pieces of rock in the intertidal zone; the most suitable places being the mouths of estuaries where there is a constant flow of freshwater (Awati and Rai, 1931). These characteristics are found in some environments of southeast of Brazil, which favors the free development of the species coming through ballast water and ship hulls. In marine ecosystems, invasive exotic marine species can dis- place native species, cause the loss of native genotypes, mod- ify habitats, change community structure, affect ecosystem pro- cesses, prevent the provision of ecosystem services, impact hu- man health, and cause substantial economic losses (Grosholz, https://doi.org/10.1016/j.rsma.2019.100924 2352-4855/© 2019 Elsevier B.V. All rights reserved.