FN Archimer Export Format PT J TI Effects of the toxic dinoflagellates Prorocentrum lima and Ostreopsis cf. ovata on immune responses of cultured oysters Crassostrea gasar BT AF Faustino, Lucemberg Sales Queiroga, Fernando Ramos Hégaret, Helene Santos, Luís Fernando Marques Neves, Raquel A.F. Nascimento, Silvia da Silva, Patrícia Mirella AS 1:1;2:1,2;3:3;4:4;5:5;6:5;7:1; FF 1:;2:;3:;4:;5:;6:;7:; C1 Laboratory of Immunology and Pathology of Marine Invertebrates (LABIPI), Department of Molecular Biology, Federal University of Paraíba (UFPB), CEP 58051-900, João Pessoa, Paraíba, Brazil. Faculdade de Enfermagem Nova Esperança (FACENE), CEP 58067-695, João Pessoa, Paraíba, Brazil CNRS, Univ Brest, IRD, Ifremer, LEMAR, F-29280, Plouzané, France Cell and Developmental Biology Laboratory (LABID), Department of Molecular Biology, Federal University of Paraíba (UFPB), CEP 58051-900, João Pessoa, Paraíba, Brazil Research Group of Experimental and Applied Aquatic Ecology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil C2 UNIV FED PARAIBA, BRAZIL FACENE, BRAZIL CNRS, FRANCE UNIV FED PARAIBA, BRAZIL UNIV STATERIO JANEIRO (UNIRIO), BRAZIL UM LEMAR IN WOS Cotutelle UMR copubli-int-hors-europe copubli-sud IF 5.202 TC 3 UR https://archimer.ifremer.fr/doc/00693/80469/83597.pdf LA English DT Article DE ;Bivalve;Harmful algal blooms;Histopathology;Hemocytes;Toxic dinoflagellate;Benthic;Oyster AB Oyster production in Brazil has been highlighted as an important economic activity and is directly impacted by the quality of the environment, which is largely the result of human interference and climate change. Harmful algal blooms occur in aquatic ecosystems worldwide, including coastal marine environments which have been increasing over the last decades as a result of global change and anthropogenic activities. In this study, the native oysters Crassostrea gasar from Northeast of Brazil were exposed to two toxic benthic dinoflagellate species, Prorocentrum lima and Ostreopsis cf. ovata. Their respective effects on C. gasar physiology and defense mechanisms were investigated. Oyster hemocytes were first exposed in vitro to different concentrations of both dinoflagellate species to assess their effects on hemocyte functions, such as phagocytosis, production of reactive oxygen species, as well as mortality. Results highlighted an alteration of hemocyte phagocytosis and viability in presence of O. cf. ovata, whereas P. lima did not affect the measured hemocyte functions. In a second experiment, oysters were exposed for 4 days in vivo to toxic culture of O. cf. ovata to assess its effects on hemocyte parameters, tissues damages and pathogenic Perkinsus spp. infection. An increase in hemocyte mortality was also observed in vivo, associated with a decrease of ROS production. Histopathological analyses demonstrated a thinning of the epithelium of the digestive tubules of the digestive gland, inflammatory reaction and a significant increase in the level of infection by Perkinsus spp. in oysters exposed to O. cf. ovata. These results indicate that oysters C. gasar seem to be pretty resilient to an exposure to P. lima and may be more susceptible to O. cf. ovata. Furthermore, the latter clearly impaired oyster physiology and defense mechanisms, thus highlighting that harmful algal blooms of O. cf. ovata could potentially lead to increased susceptibility of C. gasar oysters to parasite infections. PY 2021 PD JUN SO Aquatic Toxicology SN 0166-445X PU Elsevier BV VL 236 UT 000663678600005 DI 10.1016/j.aquatox.2021.105846 ID 80469 ER EF