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Silvia M. Nascimento
Laboratory of Marine Microalgae, Department of Ecology and Marine Resources, Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur 458-314B, 22290-240 Rio de Janeiro, Brazil

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Journal article
Published: 07 November 2020 in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology
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Even though marine dinoflagellates are important primary producers, many toxic species may alter the natural equilibrium of aquatic ecosystems and even generate human intoxication incidents, as they are the major causative agents of harmful algal blooms. In order to deepen the knowledge regarding benthic dinoflagellate adverse effects, the present study aims to clarify the influence of Gambierdiscus excentricus strain UNR-08, Ostreopsis cf. ovata strain UNR-03 and Prorocentrum lima strain UNR-01 crude extracts on rat mitochondrial energetic function and permeability transition pore (mPTP) induction. Our results, expressed in number of dinoflagellate cell toxic compounds tested in a milligram of mitochondrial protein, revealed that 934 cells mg prot−1 of G. excentricus, and 7143 cells mg prot−1 of both O. cf. ovata and P. lima negatively affect mitochondrial function, including by decreasing ATP synthesis-related membrane potential variations. Moreover, considerably much lower concentrations of dinoflagellate extracts (117 cells mg prot−1 of G. excentricus, 1429 cells mg prot−1 of O. cf. ovata and 714 cells mg prot−1 of P. lima) produced mPTP-induced swelling in Ca2+-loaded isolated mitochondria. The present study clearly demonstrates the toxicity of G. excentricus, O. cf. ovata and P. lima extracts at the mitochondrial level, which may lead to mitochondrial failure and consequent cell toxicity, and that G. excentricus always provide much more severe effects than O. cf. ovata and P. lima.

ACS Style

Ana T. Varela; Raquel A.F. Neves; Silvia M. Nascimento; Paulo J. Oliveira; Miguel A. Pardal; Elsa T. Rodrigues; António J. Moreno. Exposure to marine benthic dinoflagellate toxins may lead to mitochondrial dysfunction. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 2020, 240, 108937 .

AMA Style

Ana T. Varela, Raquel A.F. Neves, Silvia M. Nascimento, Paulo J. Oliveira, Miguel A. Pardal, Elsa T. Rodrigues, António J. Moreno. Exposure to marine benthic dinoflagellate toxins may lead to mitochondrial dysfunction. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. 2020; 240 ():108937.

Chicago/Turabian Style

Ana T. Varela; Raquel A.F. Neves; Silvia M. Nascimento; Paulo J. Oliveira; Miguel A. Pardal; Elsa T. Rodrigues; António J. Moreno. 2020. "Exposure to marine benthic dinoflagellate toxins may lead to mitochondrial dysfunction." Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 240, no. : 108937.

Journal article
Published: 28 July 2020 in Marine Pollution Bulletin
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Ostreopsis is a benthic dinoflagellate genus comprising eleven species including seven that are toxigenic. Ostreopsis lenticularis was first described from French Polynesia and is widely distributed in many insular locations from the Pacific Ocean. The current study presents morphological and molecular evidence of the presence of O. lenticularis at the Fernando de Noronha Archipelago, South Atlantic. Light microscopy and scanning electron microscopy of field cells showed morphological features in agreement with the description of O. lenticularis. Cells were broadly oval, 66.0–117.5 μm in dorso-ventral diameter, 50.0–92.5 μm in width, with thecal plates presenting two kinds of pores. Phylogenetic analyses based on LSU (D1-D3) and ITS sequences from field cells from Fernando de Noronha clustered with O. lenticularis sequences from elsewhere. The species was present in low to high abundances. The current study expands the distribution of O. lenticularis to Fernando de Noronha Archipelago in the South Atlantic Ocean.

ACS Style

Geovanna Theobald Borsato; Fabiano Salgueiro; Cristhian Gomes Tavares da Silva; Adriana D. Menezes-Salgueiro; Silvia M. Nascimento. Ostreopsis lenticularis Y. Fukuyo (Dinophyceae, Gonyaulacales) from the South Atlantic Ocean: morphological and molecular characterization. Marine Pollution Bulletin 2020, 158, 111441 .

AMA Style

Geovanna Theobald Borsato, Fabiano Salgueiro, Cristhian Gomes Tavares da Silva, Adriana D. Menezes-Salgueiro, Silvia M. Nascimento. Ostreopsis lenticularis Y. Fukuyo (Dinophyceae, Gonyaulacales) from the South Atlantic Ocean: morphological and molecular characterization. Marine Pollution Bulletin. 2020; 158 ():111441.

Chicago/Turabian Style

Geovanna Theobald Borsato; Fabiano Salgueiro; Cristhian Gomes Tavares da Silva; Adriana D. Menezes-Salgueiro; Silvia M. Nascimento. 2020. "Ostreopsis lenticularis Y. Fukuyo (Dinophyceae, Gonyaulacales) from the South Atlantic Ocean: morphological and molecular characterization." Marine Pollution Bulletin 158, no. : 111441.

Journal article
Published: 07 April 2020 in Aquatic Toxicology
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Ciguatera fish poisoning is a frequently reported non-bacterial food-borne illness related to the consumption of seafood contaminated with ciguatoxins, and possibly maitotoxins. These toxins are synthesized by marine dinoflagellate species of Gambierdiscus and Fukuyoa genera, and their abundance is a matter of great concern due to their adverse effects to aquatic life and human health. The present study aims to assess the sensitivity of rat cardiomyoblast H9c2(2−1) cells to Gambierdiscus toxic compounds using concentration- and time-dependent sulforhodamine B (SRB) colorimetric assays. Low concentrations of Gambierdiscus extracts (corresponding to 1.3–2.3 cells mL−1) induced a concentration-dependent response. Specificity in time-dependent response of H9c2(2−1) cells was demonstrated for G. excentricus after a 180 min exposure compared to both G. cf. belizeanus and G. silvae species, with EC50s obtained after 720 and 360 min, respectively. The sensitivity of H9c2(2−1) cells to dinoflagellate toxic compounds was also tested with other genera from benthic (Coolia malayensis, Ostreopsis cf. ovata, Prorocentrum hoffmannianum and P. lima) and planktonic (Amphidinium carterae and Lingulodinium polyedrum) habitats. Amphidinium, Coolia and Lingulodinium data did not present any concentration-response relationships, and EC50 values could only be obtained after 720 and 1440 min of exposure to both Prorocentrum species and O. cf. ovata, respectively. This study demonstrated that the H9c2(2−1) SRB assay represents a promising and sensitive tool for the detection of Gambierdiscus toxic compounds present in water samples, particularly of G. excentricus at very low cell abundances.

ACS Style

Raquel A F Neves; Miguel A Pardal; Silvia M Nascimento; Alexandra Silva; Paulo J Oliveira; Elsa T Rodrigues. High sensitivity of rat cardiomyoblast H9c2(2-1) cells to Gambierdiscus toxic compounds. Aquatic Toxicology 2020, 223, 105475 .

AMA Style

Raquel A F Neves, Miguel A Pardal, Silvia M Nascimento, Alexandra Silva, Paulo J Oliveira, Elsa T Rodrigues. High sensitivity of rat cardiomyoblast H9c2(2-1) cells to Gambierdiscus toxic compounds. Aquatic Toxicology. 2020; 223 ():105475.

Chicago/Turabian Style

Raquel A F Neves; Miguel A Pardal; Silvia M Nascimento; Alexandra Silva; Paulo J Oliveira; Elsa T Rodrigues. 2020. "High sensitivity of rat cardiomyoblast H9c2(2-1) cells to Gambierdiscus toxic compounds." Aquatic Toxicology 223, no. : 105475.

Journal article
Published: 01 April 2020 in Ecotoxicology and Environmental Safety
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Complementary studies at different levels of the biological organization are fundamental to fully link environmental exposure to marine benthic dinoflagellate toxins and their effects. In order to contribute to this transdisciplinary evaluation, and for the first time, the present study aims to study the effects of Gambierdiscus excentricus, Ostreopsis cf. ovata, Prorocentrum hoffmannianum and Prorocentrum lima extracts on seven functionally different mammalian cell lines: HEK 293, HepG2, HNDF, H9c2(2–1), MC3T3-E1, Raw 264.7 and SH-SY5Y. All the cell lines presented cell mass decrease in a concentration-dependence of dinoflagellate extracts, exhibiting marked differences in cell toxicity. Gambierdiscus excentricus presented the highest effect, at very low concentrations with EC50,24h (i.e., the concentration that gives half-maximal response after a 24-h exposure) between 1.3 and 13 cells mL−1, followed by O. cf. ovata (EC50,24h between 3.3 and 40 cells mL−1), and Prorocentrum species (P. lima: EC50,24h between 191 and 1027 cells mL−1 and P. hoffmannianum: EC50,24h between 152 and 783 cells mL−1). Cellular specificities were also detected and rat cardiomyoblast H9c2(2–1) cells were in general the most sensitive to dinoflagellate toxic compounds, suggesting that this cell line is an animal-free potential model for dinoflagellate toxin testing. Finally, the sensitivity of cells expressing distinct phenotypes to each dinoflagellate extract exhibited low relation to human poisoning symptoms.

ACS Style

Raquel A.F. Neves; Miguel A. Pardal; Silvia M. Nascimento; Paulo J. Oliveira; Elsa T. Rodrigues. Screening-level evaluation of marine benthic dinoflagellates toxicity using mammalian cell lines. Ecotoxicology and Environmental Safety 2020, 195, 110465 .

AMA Style

Raquel A.F. Neves, Miguel A. Pardal, Silvia M. Nascimento, Paulo J. Oliveira, Elsa T. Rodrigues. Screening-level evaluation of marine benthic dinoflagellates toxicity using mammalian cell lines. Ecotoxicology and Environmental Safety. 2020; 195 ():110465.

Chicago/Turabian Style

Raquel A.F. Neves; Miguel A. Pardal; Silvia M. Nascimento; Paulo J. Oliveira; Elsa T. Rodrigues. 2020. "Screening-level evaluation of marine benthic dinoflagellates toxicity using mammalian cell lines." Ecotoxicology and Environmental Safety 195, no. : 110465.

Short communication
Published: 30 March 2020 in Environmental Toxicology and Pharmacology
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Mitochondria was used to clarify the effects of Coolia malayensis strain UNR-02 crude extract by studying mitochondrial membrane potential (ΔΨm) generation and the fluctuations of ΔΨm associated with the induction of mitochondrial permeability transition (MPT). The cytoxicity of C. malayensis was also determined using both HepG2 and H9c2(2−1) cells. C. malayensis extract significantly depressed the oxidative phosphorylation efficiency, as was inferred from the perturbations in ΔΨm and in the phosphorylative cycle induced by ADP. Increased susceptibility to Ca2+-induced MPT was also observed. At the cellular level, the extract significantly decreased cell mass of both cell lines.

ACS Style

Ana T. Varela; Raquel A.F. Neves; Silvia M. Nascimento; Paulo J. Oliveira; Miguel A. Pardal; Elsa T. Rodrigues; António J. Moreno. Mitochondrial impairment and cytotoxicity effects induced by the marine epibenthic dinoflagellate Coolia malayensis. Environmental Toxicology and Pharmacology 2020, 77, 103379 .

AMA Style

Ana T. Varela, Raquel A.F. Neves, Silvia M. Nascimento, Paulo J. Oliveira, Miguel A. Pardal, Elsa T. Rodrigues, António J. Moreno. Mitochondrial impairment and cytotoxicity effects induced by the marine epibenthic dinoflagellate Coolia malayensis. Environmental Toxicology and Pharmacology. 2020; 77 ():103379.

Chicago/Turabian Style

Ana T. Varela; Raquel A.F. Neves; Silvia M. Nascimento; Paulo J. Oliveira; Miguel A. Pardal; Elsa T. Rodrigues; António J. Moreno. 2020. "Mitochondrial impairment and cytotoxicity effects induced by the marine epibenthic dinoflagellate Coolia malayensis." Environmental Toxicology and Pharmacology 77, no. : 103379.

Journal article
Published: 22 January 2020 in Toxins
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Recurrent blooms of Ostreopsis cf. ovata have been reported in Brazil and the Mediterranean Sea with associated ecological, and in the latter case, health impacts. Molecular data based on the D1–D3 and D8–D10 regions of the LSU rDNA and ITS loci, and the morphology of O. cf. ovata isolates and field populations from locations along the Brazilian tropical and subtropical coastal regions and three oceanic islands are presented. Additional ITS sequences from three single cells from the tropical coast are provided. Toxin profiles and quantities of PLTX and their analogues; OVTXs; contained in cells from two clonal cultures and two field blooms from Rio de Janeiro were investigated. Morphology was examined using both light and epifluorescence microscopy. Morphometric analysis of different strains and field populations from diverse locations were compared. Molecular analysis showed that six of the seven sequences grouped at the large “Atlantic/Mediterranean/Pacific” sub-clade, while one sequence branched in a sister clade with sequences from Madeira Island and Greece. The toxin profile of strains and bloom field samples from Rio de Janeiro were dominated by OVTX-a and -b, with total cell quotas (31.3 and 39.3 pg cell−1) in the range of that previously reported for strains of O. cf. ovata.

ACS Style

Silvia Nascimento; Raquel Neves; Gabriela De’Carli; Geovanna Borsato; Rodrigo da Silva; Guilherme Melo; Agatha de Morais; Thais Cockell; Santiago Fraga; Adriana Menezes-Salgueiro; Luiz Mafra; Philipp Hess; Fabiano Salgueiro. Ostreopsis cf. ovata (Dinophyceae) Molecular Phylogeny, Morphology, and Detection of Ovatoxins in Strains and Field Samples from Brazil. Toxins 2020, 12, 70 .

AMA Style

Silvia Nascimento, Raquel Neves, Gabriela De’Carli, Geovanna Borsato, Rodrigo da Silva, Guilherme Melo, Agatha de Morais, Thais Cockell, Santiago Fraga, Adriana Menezes-Salgueiro, Luiz Mafra, Philipp Hess, Fabiano Salgueiro. Ostreopsis cf. ovata (Dinophyceae) Molecular Phylogeny, Morphology, and Detection of Ovatoxins in Strains and Field Samples from Brazil. Toxins. 2020; 12 (2):70.

Chicago/Turabian Style

Silvia Nascimento; Raquel Neves; Gabriela De’Carli; Geovanna Borsato; Rodrigo da Silva; Guilherme Melo; Agatha de Morais; Thais Cockell; Santiago Fraga; Adriana Menezes-Salgueiro; Luiz Mafra; Philipp Hess; Fabiano Salgueiro. 2020. "Ostreopsis cf. ovata (Dinophyceae) Molecular Phylogeny, Morphology, and Detection of Ovatoxins in Strains and Field Samples from Brazil." Toxins 12, no. 2: 70.

Journal article
Published: 15 January 2020 in Journal of Experimental Marine Biology and Ecology
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Toxins synthesized by marine benthic dinoflagellates may be transferred towards higher trophic levels via cell ingestion. Okadaic acid (OA) and other compounds produced by benthic Prorocentrum species are associated with acute and lethal fish responses, but its sublethal effects are barely known. The toxicity of low and intermediate P. lima concentrations to the ringneck blenny Parablennius pilicornis was evaluated through short-term food chain transfer experiments using brine shrimps as primary grazers of toxic cells and, subsequently, as fish prey. Fish activity level, opercular beat frequency, feces biomass, condition factor, and hepatosomatic index were used as toxicity proxies. We hypothesized that sub-lethal concentrations of DSP toxins will affect fish responses, but the strength of these effects will be mediated by the initial somatic condition of exposed individuals. Increased opercular beat frequencies were recorded in fish from the treatment with the highest P. lima concentration provided to brine shrimps, contrasting with rather variable and low opercular beat frequencies from the control. Fish fed with brine shrimps exposed to low and intermediate concentrations of P. lima showed a great inter-individual variation in activity level and particularly in opercular beat frequency, wherein the initial condition factor of exposed individuals appeared to have broadly mediated these fish responses. The presence of P. lima all year round in benthic marine systems highlights a possible chronic exposure of fish to OA and fish will likely become more susceptible to predation in natural environments, facilitating, therefore, toxin transfer through marine trophic webs.

ACS Style

Raquel A.F. Neves; Silvia M. Nascimento; Luciano N. Santos. Sublethal fish responses to short-term food chain transfer of DSP toxins: The role of somatic condition. Journal of Experimental Marine Biology and Ecology 2020, 524, 151317 .

AMA Style

Raquel A.F. Neves, Silvia M. Nascimento, Luciano N. Santos. Sublethal fish responses to short-term food chain transfer of DSP toxins: The role of somatic condition. Journal of Experimental Marine Biology and Ecology. 2020; 524 ():151317.

Chicago/Turabian Style

Raquel A.F. Neves; Silvia M. Nascimento; Luciano N. Santos. 2020. "Sublethal fish responses to short-term food chain transfer of DSP toxins: The role of somatic condition." Journal of Experimental Marine Biology and Ecology 524, no. : 151317.

Articles
Published: 14 June 2019 in European Journal of Phycology
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The morphology and molecular phylogenetic relationships of Coolia species isolated from Brazil, including C. malayensis, C. tropicalis and a new lineage of the Coolia canariensis complex, are presented. Morphology was investigated by light and scanning electron microscopy. No significant morphological differences between the Brazilian strains and other geographically distant strains of C. malayensis and C. tropicalis were observed. In LSU and ITS rDNA phylogenies C. malayensis and C. tropicalis sequences from Brazil branched within the clade of these species with strains isolated from elsewhere. Phylogenetic relationships (LSU rDNA) within the C. canariensis species complex support the existence of three cryptic species. No morphological difference was discernible among species in this complex. Additional molecular, morphological and toxin data from globally distributed isolates should be acquired to strengthen our knowledge of the C. canariensis species complex.

ACS Style

Silvia M. Nascimento; Rodrigo A. F. Da Silva; Fernanda Oliveira; Santiago Fraga; Fabiano Salgueiro. Morphology and molecular phylogeny of Coolia tropicalis, Coolia malayensis and a new lineage of the Coolia canariensis species complex (Dinophyceae) isolated from Brazil. European Journal of Phycology 2019, 54, 484 -496.

AMA Style

Silvia M. Nascimento, Rodrigo A. F. Da Silva, Fernanda Oliveira, Santiago Fraga, Fabiano Salgueiro. Morphology and molecular phylogeny of Coolia tropicalis, Coolia malayensis and a new lineage of the Coolia canariensis species complex (Dinophyceae) isolated from Brazil. European Journal of Phycology. 2019; 54 (3):484-496.

Chicago/Turabian Style

Silvia M. Nascimento; Rodrigo A. F. Da Silva; Fernanda Oliveira; Santiago Fraga; Fabiano Salgueiro. 2019. "Morphology and molecular phylogeny of Coolia tropicalis, Coolia malayensis and a new lineage of the Coolia canariensis species complex (Dinophyceae) isolated from Brazil." European Journal of Phycology 54, no. 3: 484-496.

Journal article
Published: 19 March 2019 in Marine Environmental Research
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Prorocentrum lima is a widely distributed marine benthic dinoflagellate that produces diarrhetic toxins, okadaic acid (OA) and its analogs, that may promote damage on bivalve tissues and cellular responses. Cultivation of the brown mussel Perna perna represents an important economic activity in the tropical and subtropical regions, where mussels may co-occur with P. lima. This study aimed to assess the behavioral, cellular immune responses, and pathological condition of P. perna following a short-term experimental exposure to P. lima. The toxic dinoflagellate treatment was compared to a non-toxic exposure to the chlorophyte Tetraselmis sp. at similar concentrations. The prevalence of pathological conditions and parasites were assessed, and a pathological index was applied by scoring the prevalences into four levels. Reaction time and the number of stimuli necessary for shell-valve closure response significantly increased after 72 h of P. lima exposure. Circulating hemocyte concentration was significantly lower in P. lima exposed mussels than in control mussels at 48- and 96 h of incubation, while hemocyte relative size in exposed mussels was significantly higher than that in control mussels. Comparatively, phagocytic activity and ROS production by hemocytes was significantly higher in mussels exposed to P. lima at 48- and 96 h of incubation, respectively. In addition, exposed mussels significantly presented exacerbated hemocytic infiltration in digestive organs, higher prevalence of moderate to severe atrophy in digestive tubules, and higher pathological index which suggests an impairment of mussel immunologic responses. A lower prevalence of Rickettsia-like organisms (RLOs), trematodes and copepods in P. lima exposed mussels suggests a direct toxic effect of OA on parasites. The exposure of mussels to P. lima is likely to occur frequently and may lead to constraints on mussel behavior, physiology, and pathological condition.

ACS Style

Raquel A.F. Neves; Tainá Cristina Santiago; Wanderson F. Carvalho; Edson Dos Santos Silva; Patricia Mirella da Silva; Silvia Nascimento. Impacts of the toxic benthic dinoflagellate Prorocentrum lima on the brown mussel Perna perna: Shell-valve closure response, immunology, and histopathology. Marine Environmental Research 2019, 146, 35 -45.

AMA Style

Raquel A.F. Neves, Tainá Cristina Santiago, Wanderson F. Carvalho, Edson Dos Santos Silva, Patricia Mirella da Silva, Silvia Nascimento. Impacts of the toxic benthic dinoflagellate Prorocentrum lima on the brown mussel Perna perna: Shell-valve closure response, immunology, and histopathology. Marine Environmental Research. 2019; 146 ():35-45.

Chicago/Turabian Style

Raquel A.F. Neves; Tainá Cristina Santiago; Wanderson F. Carvalho; Edson Dos Santos Silva; Patricia Mirella da Silva; Silvia Nascimento. 2019. "Impacts of the toxic benthic dinoflagellate Prorocentrum lima on the brown mussel Perna perna: Shell-valve closure response, immunology, and histopathology." Marine Environmental Research 146, no. : 35-45.

Journal article
Published: 01 April 2018 in Marine Environmental Research
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Blooms of the benthic dinoflagellate Ostreopsis cf. ovata have been recorded with increasing frequency, intensity and geographic distribution. This dinoflagellate produces potent toxins that may cause mortality of marine invertebrates. Adults of sea urchins are commonly affected by O. cf. ovata exposure with evidence of spines loss and high mortality during periods of high dinoflagellate abundances. Here, we report on the effects of the toxic dinoflagellate O. cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus, a key ecological herbivore. Lytechinus variegatus eggs and sperm were experimentally exposed to different concentrations of Ostreopsis cf. ovata (4, 40, 400, and 4000 cells ml−1) to test the hypothesis that fertilization success, embryonic and larval development of the sea urchin are negatively affected by the toxic dinoflagellate even at low abundances. Reduced fertilization, developmental failures, embryo and larval mortality, and occurrence of abnormal offspring were evident after exposure to O. cf. ovata. Fertilization decreased when gametes were exposed to high O. cf. ovata abundances (400 and 4000 cells ml−1), but just the exposure to the highest abundance significantly reduced fertilization success. Sea urchin early development was affected by O. cf. ovata in a dose-dependent way, high dinoflagellate abundances fully inhibited the early development of L. variegatus. Ostreopsis cf. ovata significantly increased the mortality of sea urchin eggs and embryos in the first hours of exposure (∼1–3 h), regardless of dinoflagellate abundance. Abundances of 400 and 4000 O. cf. ovata cells ml−1 induced significantly higher mortality on sea urchin initial stages in the first hours, and no egg or embryo was found in these treatments after 18 h of incubation. The early echinopluteus larva was only reached in the control and in treatments with low Ostreopsis cf. ovata abundances (4 and 40 cells ml−1). The exposure to O. cf. ovata led to significantly higher occurrence of skeletal anomalies in the early larva of L. variegatus. Interactions of sea urchin gametes and Ostreopsis cells may naturally occur in coastal areas due to the match between O. cf. ovata blooms and L. variegatus reproductive period. Reduced larval density and increased larval abnormalities were observed even at low abundances (4 and 40 cells ml−1) frequently found in tropical environments all year round. The chronic exposure to O. cf. ovata could significantly impact larval fitness, thus compromising recruitment success, and highlight the negative effects of benthic HABs on sea urchin populations and its possible broader ecological implications.

ACS Style

Raquel A.F. Neves; Mariana Contins; Silvia M. Nascimento. Effects of the toxic benthic dinoflagellate Ostreopsis cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus. Marine Environmental Research 2018, 135, 11 -17.

AMA Style

Raquel A.F. Neves, Mariana Contins, Silvia M. Nascimento. Effects of the toxic benthic dinoflagellate Ostreopsis cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus. Marine Environmental Research. 2018; 135 ():11-17.

Chicago/Turabian Style

Raquel A.F. Neves; Mariana Contins; Silvia M. Nascimento. 2018. "Effects of the toxic benthic dinoflagellate Ostreopsis cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus." Marine Environmental Research 135, no. : 11-17.

Journal article
Published: 01 December 2017 in Harmful Algae
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A new species of toxic benthic dinoflagellate is described based on laboratory cultures isolated from two locations from Brazil, Rio de Janeiro and Bahia. The morphology was studied with SEM and LM. Cells are elliptical in right thecal view and flat. They are 37-44μm long and 29-36μm wide. The right thecal plate has a V shaped indentation where six platelets can be identified. The thecal surface of both thecal plates is smooth and has round or kidney shaped and uniformly distributed pores except in the central area of the cell, and a line of marginal pores. Some cells present an elongated depression on the central area of the apical part of the right thecal plate. Prorocentrum caipirignum is similar to Prorocentrum lima in its morphology, but can be differentiated by the general cell shape, being elliptical while P. lima is ovoid. In the phylogenetic trees based on ITS and LSU rDNA sequences, the P. caipirignum clade appears close to the clades of P. lima and Prorocentrum hoffmannianum. The Brazilian strains of P. caipirignum formed a clade with strains from Cuba, Hainan Island and Malaysia and it is therefore likely that this new species has a broad tropical distribution. Prorocentrum caipirignum is a toxic species that produces okadaic acid and the fast acting toxin prorocentrolide.

ACS Style

Silvia M. Nascimento; M. Cristina Q. Mendes; Mariângela Menezes; Francisco Rodríguez; Catharina Alves-De-Souza; Suema Branco; Pilar Riobó; José Franco; José Marcos C. Nunes; Mariusz Huk; Steven Morris; Santiago Fraga. Morphology and phylogeny of Prorocentrum caipirignum sp. nov. (Dinophyceae), a new tropical toxic benthic dinoflagellate. Harmful Algae 2017, 70, 73 -89.

AMA Style

Silvia M. Nascimento, M. Cristina Q. Mendes, Mariângela Menezes, Francisco Rodríguez, Catharina Alves-De-Souza, Suema Branco, Pilar Riobó, José Franco, José Marcos C. Nunes, Mariusz Huk, Steven Morris, Santiago Fraga. Morphology and phylogeny of Prorocentrum caipirignum sp. nov. (Dinophyceae), a new tropical toxic benthic dinoflagellate. Harmful Algae. 2017; 70 ():73-89.

Chicago/Turabian Style

Silvia M. Nascimento; M. Cristina Q. Mendes; Mariângela Menezes; Francisco Rodríguez; Catharina Alves-De-Souza; Suema Branco; Pilar Riobó; José Franco; José Marcos C. Nunes; Mariusz Huk; Steven Morris; Santiago Fraga. 2017. "Morphology and phylogeny of Prorocentrum caipirignum sp. nov. (Dinophyceae), a new tropical toxic benthic dinoflagellate." Harmful Algae 70, no. : 73-89.

Original articles
Published: 01 September 2017 in Brazilian Journal of Oceanography
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Mixotrophy has been shown to be a common trait among dinoflagellates and its importance in the nutritional ecology of harmful algae has been hypothesized. Benthic harmful species have not been extensively investigated as their planktonic counterparts and there are major gaps in the knowledge of their nutritional strategies. In this study the occurrence of phagotrophy was investigated in natural assemblages of benthic dinoflagellates using epi-fluorescence microscopy with DAPI and LysoSensor staining. The study was conducted at five sites along the coast of Rio de Janeiro that were visited in January, August and December 2010. In total, 1659 dinoflagellate cells were observed. From these, only 0.4% of 1195 Ostreopsis cf. ovata and 2.2% of 134 Coolia spp. cells presented evidence of phagotrophy with vacuoles stained by LysoSensor or a DAPI (4',6-diamidino-2-phenylindole) stained inclusion. Stained vacuoles were not registered in the 330 Prorocentrum spp. cells observed. Few O. cf. ovata cells contained round red inclusions ("red spots") that were not stained either by DAPI or LysoSensor, suggesting that these structures are not ingested prey. The results showed that phagotrophy was not a frequent nutritional strategy in benthic dinoflagellates during the study period.

ACS Style

Eliliane Vasconcelos Corrêa Almada; Wanderson Fernandes De Carvalho; Silvia Mattos Nascimento. Investigation of phagotrophy in natural assemblages of the benthic dinoflagellates Ostreopsis, Prorocentrum and Coolia. Brazilian Journal of Oceanography 2017, 65, 392 -399.

AMA Style

Eliliane Vasconcelos Corrêa Almada, Wanderson Fernandes De Carvalho, Silvia Mattos Nascimento. Investigation of phagotrophy in natural assemblages of the benthic dinoflagellates Ostreopsis, Prorocentrum and Coolia. Brazilian Journal of Oceanography. 2017; 65 (3):392-399.

Chicago/Turabian Style

Eliliane Vasconcelos Corrêa Almada; Wanderson Fernandes De Carvalho; Silvia Mattos Nascimento. 2017. "Investigation of phagotrophy in natural assemblages of the benthic dinoflagellates Ostreopsis, Prorocentrum and Coolia." Brazilian Journal of Oceanography 65, no. 3: 392-399.

Journal article
Published: 11 July 2017 in Marine Drugs
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Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area.

ACS Style

Francesco Pisapia; Manoëlla Sibat; Christine Herrenknecht; Korian Lhaute; Greta Gaiani; Pierre-Jean Ferron; Valérie Fessard; Santiago Fraga; Silvia M. Nascimento; R. Wayne Litaker; William C. Holland; Catherine Roullier; Philipp Hess. Maitotoxin-4, a Novel MTX Analog Produced by Gambierdiscus excentricus. Marine Drugs 2017, 15, 220 .

AMA Style

Francesco Pisapia, Manoëlla Sibat, Christine Herrenknecht, Korian Lhaute, Greta Gaiani, Pierre-Jean Ferron, Valérie Fessard, Santiago Fraga, Silvia M. Nascimento, R. Wayne Litaker, William C. Holland, Catherine Roullier, Philipp Hess. Maitotoxin-4, a Novel MTX Analog Produced by Gambierdiscus excentricus. Marine Drugs. 2017; 15 (7):220.

Chicago/Turabian Style

Francesco Pisapia; Manoëlla Sibat; Christine Herrenknecht; Korian Lhaute; Greta Gaiani; Pierre-Jean Ferron; Valérie Fessard; Santiago Fraga; Silvia M. Nascimento; R. Wayne Litaker; William C. Holland; Catherine Roullier; Philipp Hess. 2017. "Maitotoxin-4, a Novel MTX Analog Produced by Gambierdiscus excentricus." Marine Drugs 15, no. 7: 220.

Journal article
Published: 05 June 2017 in New Zealand Journal of Botany
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Erick Lopes Filho; Fabiano Salgueiro; Silvia Nascimento; M. Cecilia Gauna; Elisa R. Parodi; Joel Campos De Paula. Molecular evidence of the presence of Dictyota dichotoma (Dictyotales: Phaeophyceae) in Argentina based on sequences from mtDNA and cpDNA and a discussion of its possible origin. New Zealand Journal of Botany 2017, 55, 293 -305.

AMA Style

Erick Lopes Filho, Fabiano Salgueiro, Silvia Nascimento, M. Cecilia Gauna, Elisa R. Parodi, Joel Campos De Paula. Molecular evidence of the presence of Dictyota dichotoma (Dictyotales: Phaeophyceae) in Argentina based on sequences from mtDNA and cpDNA and a discussion of its possible origin. New Zealand Journal of Botany. 2017; 55 (3):293-305.

Chicago/Turabian Style

Erick Lopes Filho; Fabiano Salgueiro; Silvia Nascimento; M. Cecilia Gauna; Elisa R. Parodi; Joel Campos De Paula. 2017. "Molecular evidence of the presence of Dictyota dichotoma (Dictyotales: Phaeophyceae) in Argentina based on sequences from mtDNA and cpDNA and a discussion of its possible origin." New Zealand Journal of Botany 55, no. 3: 293-305.

Research article
Published: 07 April 2017 in PLoS ONE
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Harmful algae may differently affect their primary grazers, causing sub-lethal effects and/or leading to their death. The present study aim to compare the effects of three toxic benthic dinoflagellates on clearance and grazing rates, behavioral changes, and survival of Artemia salina. Feeding assays consisted in 1-h incubations of brine shrimps with the toxic Prorocentrum lima, Gambierdiscus excentricus and Ostreopsis cf. ovata and the non-toxic Tetraselmis sp. Brine shrimps fed unselectively on all toxic and non-toxic algal preys, without significant differences in clearance and ingestion rates. Acute toxicity assays were performed with dinoflagellate cells in two growth phases during 7-h to assess differences in cell toxicity to A. salina. Additionally, exposure to cell-free medium was performed to evaluate its effects on A. salina survival. The behavior of brine shrimps significantly changed during exposure to the toxic dinoflagellates, becoming immobile at the bottom by the end of the trials. Dinoflagellates significantly affected A. salina survival with 100% mortality after 7-h exposure to cells in exponential phase (all treatments) and to P. lima in stationary phase. Mortality rates of brine shrimps exposed to O. cf. ovata and G. excentricus in stationary phase were 91% and 75%, respectively. However, incubations of the brine shrimps with cell-free medium did not affect A. salina survivorship. Significant differences in toxic effects between cell growth phases were only found in the survival rates of A. salina exposed to G. excentricus. Acute exposure to benthic toxic dinoflagellates induced harmful effects on behavior and survival of A. salina. Negative effects related to the toxicity of benthic dinoflagellates are thus expected on their primary grazers making them more vulnerable to predation and vectors of toxins through the marine food webs.

ACS Style

Raquel A. F. Neves; Tainá Fernandes; Luciano Neves Dos Santos; Silvia Nascimento. Toxicity of benthic dinoflagellates on grazing, behavior and survival of the brine shrimp Artemia salina. PLoS ONE 2017, 12, e0175168 .

AMA Style

Raquel A. F. Neves, Tainá Fernandes, Luciano Neves Dos Santos, Silvia Nascimento. Toxicity of benthic dinoflagellates on grazing, behavior and survival of the brine shrimp Artemia salina. PLoS ONE. 2017; 12 (4):e0175168.

Chicago/Turabian Style

Raquel A. F. Neves; Tainá Fernandes; Luciano Neves Dos Santos; Silvia Nascimento. 2017. "Toxicity of benthic dinoflagellates on grazing, behavior and survival of the brine shrimp Artemia salina." PLoS ONE 12, no. 4: e0175168.

Journal article
Published: 01 January 2017 in Botanica Marina
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The aim of this study was to describe the morphology of species of the benthic dinoflagellate genus

ACS Style

Bruna S. Diniz; Mariângela Menezes; Silvia Mattos Nascimento. Morphology of Sinophysis microcephala and Sinophysis canaliculata (Dinophyceae) from the South Atlantic Ocean. Botanica Marina 2017, 60, 79 -83.

AMA Style

Bruna S. Diniz, Mariângela Menezes, Silvia Mattos Nascimento. Morphology of Sinophysis microcephala and Sinophysis canaliculata (Dinophyceae) from the South Atlantic Ocean. Botanica Marina. 2017; 60 (1):79-83.

Chicago/Turabian Style

Bruna S. Diniz; Mariângela Menezes; Silvia Mattos Nascimento. 2017. "Morphology of Sinophysis microcephala and Sinophysis canaliculata (Dinophyceae) from the South Atlantic Ocean." Botanica Marina 60, no. 1: 79-83.

Journal article
Published: 01 July 2016 in Harmful Algae
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Morphological descriptions using light and scanning electron microscopy and molecular characterization of two Prorocentrum lima strains (UNR-01 and UNR-09) isolated from Armação dos Búzios, Rio de Janeiro, Brazil are provided. Okadaic acid (OA), dinophysistoxin-1 (DTX1) and DTX2 production by strain UNR-01 was investigated using liquid chromatography with mass spectrometry. Toxins were extracted from heat-treated (boiled) and non-boiled cell pellets to obtain respective quantities of free and total OA and DTX1. Growth parameters (growth rate and mean generation time) were determined for strain UNR-01. Prorocentrum lima cells were oblong-to-ovate in shape, broad in the middle region, and narrow at the anterior end. The periflagellar area was triangular, set into a V-shaped depression and was composed of eight periflagellar platelets of different sizes. The morphology fits well the characterization of the species isolated from elsewhere. Phylogenetic analysis based on internal transcribed spacer – ITS – and D1–D3 large subunit – LSU – of ribosomal RNA gene sequences revealed that both strains were identical and closely related to P. lima isolates from the Caribbean Sea and USA. The growth rate of strain UNR-01 was 0.24 div day−1. OA concentrations were on average 15.2 and 38.5 pg[OA] cell−1 for heat-treated and non-treated cells respectively, while DTX1 mean concentration was 0.5 pg[DTX1] cell−1 for both heat-treated and non-treated cells. DTX2 was not detected. To date, these are the first strains of P. lima from the south Atlantic that have been characterized.

ACS Style

Silvia M. Nascimento; Fabiano Salgueiro; Mariângela Menezes; Fernanda De Andréa Oliveira; Vinicius Chiapetta Portella Magalhães; Joel Campos De Paula; Steven Morris. Prorocentrum lima from the South Atlantic: Morphological, molecular and toxicological characterization. Harmful Algae 2016, 57, 39 -48.

AMA Style

Silvia M. Nascimento, Fabiano Salgueiro, Mariângela Menezes, Fernanda De Andréa Oliveira, Vinicius Chiapetta Portella Magalhães, Joel Campos De Paula, Steven Morris. Prorocentrum lima from the South Atlantic: Morphological, molecular and toxicological characterization. Harmful Algae. 2016; 57 ():39-48.

Chicago/Turabian Style

Silvia M. Nascimento; Fabiano Salgueiro; Mariângela Menezes; Fernanda De Andréa Oliveira; Vinicius Chiapetta Portella Magalhães; Joel Campos De Paula; Steven Morris. 2016. "Prorocentrum lima from the South Atlantic: Morphological, molecular and toxicological characterization." Harmful Algae 57, no. : 39-48.

Journal article
Published: 01 November 2015 in Phycologia
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Gambierdiscus excentricus is an epibenthic dinoflagellate able to produce ciguatoxin and maitotoxin-like compounds that are responsible for ciguatera fish poisoning. Morphological descriptions and molecular characterization of two G. excentricus strains isolated from Brazil and maintained in culture were provided. The most complete description of the morphology of the sulcal region of Gambierdiscus based on light and scanning electron microscopy was presented. The sulcal area morphology and nomenclature used by different authors to name the sulcal plates in Gambierdiscus were reviewed. Two small sulcal plates (S.m.a. and S.m.p.) were shown for the first time. Phylogenetic trees based on D1–D3 and D8–D10 large subunits of ribosomal RNA gene sequences showed that the strains of G. excentricus from Brazil clustered with strains of G. excentricus isolated from its type locality, the Canary Islands. Both phylogenetic trees reconstructed the same relationships among all the formally described Gambierdiscus species and Gambierdiscus sp. ribotype 2 and Gambierdiscus sp. type 2.

ACS Style

Silvia Mattos Nascimento; Guilherme Melo; Fabiano Salgueiro; Bruna Dos Santos Diniz; Santiago Fraga. Morphology of Gambierdiscus excentricus (Dinophyceae) with emphasis on sulcal plates. Phycologia 2015, 54, 628 -639.

AMA Style

Silvia Mattos Nascimento, Guilherme Melo, Fabiano Salgueiro, Bruna Dos Santos Diniz, Santiago Fraga. Morphology of Gambierdiscus excentricus (Dinophyceae) with emphasis on sulcal plates. Phycologia. 2015; 54 (6):628-639.

Chicago/Turabian Style

Silvia Mattos Nascimento; Guilherme Melo; Fabiano Salgueiro; Bruna Dos Santos Diniz; Santiago Fraga. 2015. "Morphology of Gambierdiscus excentricus (Dinophyceae) with emphasis on sulcal plates." Phycologia 54, no. 6: 628-639.

Journal article
Published: 01 May 2012 in Marine Pollution Bulletin
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The epi-benthic dinoflagellate Ostreopsis cf. ovata Fukuyo has an increasingly global distribution. In Brazil there are reports of O. cf. ovata along the coast from 8°S to 27°S latitude and blooms have been registered on the Rio de Janeiro coastline. In the current study, an O. cf. ovata bloom is reported at Saint Paul's Rocks (0°55'10″N; 29°20'33″W), between the southern and northern hemispheres. The Archipelago is not inhabited and not subjected to eutrophication, due to isolation, and sustains a number of endemic species. Therefore, blooms of O. cf. ovata may potentially cause demise to trophic chains by affecting marine invertebrates and vertebrates.

ACS Style

Silvia Mattos Nascimento; Julia Vitor França; José E.A. Gonçalves; Carlos E.L. Ferreira. Ostreopsis cf. ovata (Dinophyta) bloom in an equatorial island of the Atlantic Ocean. Marine Pollution Bulletin 2012, 64, 1074 -1078.

AMA Style

Silvia Mattos Nascimento, Julia Vitor França, José E.A. Gonçalves, Carlos E.L. Ferreira. Ostreopsis cf. ovata (Dinophyta) bloom in an equatorial island of the Atlantic Ocean. Marine Pollution Bulletin. 2012; 64 (5):1074-1078.

Chicago/Turabian Style

Silvia Mattos Nascimento; Julia Vitor França; José E.A. Gonçalves; Carlos E.L. Ferreira. 2012. "Ostreopsis cf. ovata (Dinophyta) bloom in an equatorial island of the Atlantic Ocean." Marine Pollution Bulletin 64, no. 5: 1074-1078.

Journal article
Published: 31 January 2012 in Harmful Algae
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Silvia M. Nascimento; Eliliane V. Corrêa; Mariângela Menezes; Daniel Varela; Javier Paredes; Steven Morris. Growth and toxin profile of Ostreopsis cf. ovata (Dinophyta) from Rio de Janeiro, Brazil. Harmful Algae 2012, 13, 1 -9.

AMA Style

Silvia M. Nascimento, Eliliane V. Corrêa, Mariângela Menezes, Daniel Varela, Javier Paredes, Steven Morris. Growth and toxin profile of Ostreopsis cf. ovata (Dinophyta) from Rio de Janeiro, Brazil. Harmful Algae. 2012; 13 ():1-9.

Chicago/Turabian Style

Silvia M. Nascimento; Eliliane V. Corrêa; Mariângela Menezes; Daniel Varela; Javier Paredes; Steven Morris. 2012. "Growth and toxin profile of Ostreopsis cf. ovata (Dinophyta) from Rio de Janeiro, Brazil." Harmful Algae 13, no. : 1-9.