690 resultados para Bivalves marinhos
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Dissertação de mestrado em Estudos Marinhos e Costeiros, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 2000
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A presença de Vibrio parahaemolyticus foi avaliada em 50 amostras de moluscos bivalves marinhos compostas por 40 amostras de ostras coletadas em 15 restaurantes do Rio de Janeiro e 10 amostras de mexilhões capturados de banco natural em Ponta de Itaipú - Niterói. Foram empregadas a técnica do Número Mais Provável (NMP) para a enumeração de V. parahaemolyticus utilizando Caldo Glicosado Salgado com Teepol (GSTB) e Água Peptonada Alcalina (APA) com 3% de cloreto de sódio (NaCl). Paralelamente foi realizada técnica de enriquecimento em APA com 1 e 3% de NaCl. Decorrido o período de incubação de ambas as técnicas, foi realizado plaqueamento em ágar TCBS (Tiossulfato Citrato Bile Sacarose). Todas as cepas de V. parahaemolyticus isoladas através das duas técnicas foram testadas para o fenômeno de Kanagawa e, quanto à produção de urease. Do total de 141 cepas de V. parahaemolyticus isoladas, 62% revelaram-se urease positivas e, dentre estas, os sorotipos predominantes foram O10:K?, O11:K? e O3:K57 dentre o total de 24 sorotipos urease positivos identificados. Embora todas as cepas de V. parahaemolyticus tenham sido Kanagawa negativas, os resultados apontam elevada incidência desta espécie em ostras comercializadas em restaurantes.
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Dissertação de mestrado em Ecologia
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work aims to identify and photograph grains that compose important Cretaceous carbonate units of the Potiguar Basin, represented by the Ponta do Mel and Jandaíra formations (Albian-Campanian). Petrographic investigation of thin sections was essential. The samples studied come from wells and surface samples from the collection UNESPetro – UNESP, Rio Claro. In the Ponta do Mel Formation, the grains consist of ooids, oncoids, peloids and bioclasts. Regarding to the identified bioclasts, the solenoporacean red algae, mollusks (bivalves and gastropods), echinoids, foraminifera, ostracods and worms were the dominant elements. In the Jandaíra Formation, the grains are composed by ooids, peloids and bioclasts, which are represented by green algae, mollusks (bivalves and gastropods), benthic foraminifera miliolids, worms, echinoderms and ostracods. The grains found in the Ponta do Mel Formation are somewhat similar to those found in the Jandaíra Formation, with the exception of calcareous algae. The subsurface material from the Ponta do Mel Formation is derived from the upper part of the unit, representing marine high-energy carbonates, which also contains ooids and Trocholina. The samples of Jandaíra Formation, collected in outcrops, often contain green algae, mollusks and miliolids, and come from inner shelf and lagoon facies previously described
Taxocenose de bagres marinhos (Siluriformes, Ariidae) da região estuarina de São Vicente, SP, Brasil
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O objetivo do trabalho foi analisar a taxocenose de bagres marinhos do complexo baía-estuário de São Vicente, SP. As coletas foram mensais, no período de setembro de 2000 a agosto de 2002, em quatro regiões do estuário. Foram capturados 3.985 exemplares, pertencentes a cinco gêneros e seis espécies, totalizando 47.807 g. A espécie Cathorops spixii apresentou a maior abundância numérica com 1.569 indivíduos amostrados. No transecto I (próximo da região costeira) foi registrada a maior riqueza e no transecto IV (estuário acima) a maior abundância com 2.602 exemplares e peso de 26.236 g. Em março de 2002 registrou-se a maior abundância com 687 indivíduos e o maior peso ocorreu em fevereiro de 2002 (8.816 g). A salinidade da água de fundo, ao longo do período de estudo, variou entre 14 e 36 e a temperatura da água variou entre 19 e 30 °C. Na região amostrada foram capturados exemplares jovens e adultos, ocorrendo um predomínio de jovens, o que demonstra que esta área apresenta condições favoráveis para crescimento.
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São apresentadas novas informações sobre a distribuição geográfica de algumas espécies de peixes teleósteos que ocorrem na costa brasileira, incluindo duas espécies que nunca haviam sido registradas em nossas águas. Os serranídeos Pseudogramma gregoryi (assinalado da Flórida à Venezuela) e Plectranthias garrupellus (registrado da Carolina do Norte ao Caribe) foram encontrados, respectivamente, na costa do Ceará e na costa sudeste-sul do Brasil. São aqui mencionados e discutidos os dois primeiros registros do gênero Caristius (Caristiidae) no Brasil, bem como os primeiros registros na costa sudeste-sul do Brasil das espécies Enchelycore carychroa (Muraenidae), e Chilomycterus antillarum (Diodontidae), e da espécie Neobythites brasiliensis(Bythitidae) no nordeste do Brasil. É também assinalada a ocorrência mais setentrional do pargo Calamus mu (Sparidae), uma espécie até então circunscrita à região entre o Espírito Santo e São Paulo, e são discutidos os registros adicionais de Bascanichthys paulensis (Ophichthidae), Nezumia aequalis (Macrouridae), Antigonia combatia (Caproidae) e Notolycodes schmidti (Zoarcidae) na costa brasileira.
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Sao Paulo state, Brazil, is one of the main areas of sugar cane agriculture in the world. Herbicides, in particular, ametryn, are extensively used in this extensive area, which implies that this herbicide is present in the environment and can contaminate the surface water by running off. Thereby, residues of ametryn were analyzed in samples of river water an river sediment and in freshwater bivalves obtained from the rivers Sapucai, Pardo and Mogi-Guacu in Sao Paulo State, Brazil. Samples were taken in the winter of 2003 and 2004 in two locations in each river. The specimens of freshwater bivalves collected and analyzed were Corbicula fluminea, an exotic species, and Diplodon fontaineanus, a native species. Additionally, the evaluation of the ability of bioconcentration and depuration of ametryn by the freshwater bivalve Corbicula fluminea was also performed. Ametryn concentrations in the samples were measured by liquid chromatography coupled to mass spectrometry. Residues of ametryn in water (50 ng/L) and in freshwater bivalves (2-7 ng/g) were found in the Mogi-Guacu River in 2004, and residues in river sediments were found in all rivers in 2003 and 2004 (0.5-2 ng/g). The observation of the aquatic environment through the analysis of these matrixes, water, sediment, and bivalves, revealed the importance of the river sediment in the accumulation of the herbicide ametryn, which can contaminate the biota.
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Sperm ultrastructure in three representative species of the marine bivalve family Spondylidae (spiny or thorny oysters) is examined and compared with available data on other bivalves, especially other families of the subclass Pteriomorphia. Spondylid spermatozoa are of the externally fertilizing aquasperm. type (ect-aquasperm). The acrosomal vesicle is conical with a deep basal invagination extending almost the full length of the vesicle. Vesicle contents are divisible into an inner, highly electron-dense anterior layer and a less dense posterior layer. The anterior layer is folded back on itself posteriorly and exhibits radiating plates (best developed peripherally). The vesicle rests on, and is partially embedded in, an extensive granular deposit of subacrosomal. material at the nuclear apex. This deposit extends partly into acrosomal vesicle invagination and also fills a broad depression in the anterior of the nucleus. No pre-formed axial rod (perforatorium) is present. The nucleus is round-pyriform and its contents coarsely fibrogranular. At the base of the nucleus, four broad depressions partially accommodate the midpiece mitochondria. The midpiece consists the four spherical mitochondria and the proximal and distal centrioles. The centrioles are arranged at approximately 90degrees to each other, and each consists of nine, angularly-oriented, microtubular triplets embedded in a granular matrix. A short, periodically banded rootlet connects the proximal centriole to the nuclear fossa, whereas the distal centriole, which forms the basal body to the flagellar axoneme, is anchored to the plasma membrane by nine terminally forked satellite fibres. Extensive deposits of putative glycogen rosettes surround the centrioles and mitochondria. The flagellum consists of a 9+2 axoneme sheathed by the plasma membrane. Spondylid spermatozoa strongly resemble those of the Pectinidae, further confirming the traditional view (based on comparative anatomy and shell morphology) of a close relationship between the Spondylidae and the Pectinidae. Differences in acrosomal shape and dimensions were noted between the three species examined, indicating potential taxonomic utility for comparative sperm ultrastructure within the Spondylidae.
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Jornadas "Ciência nos Açores – que futuro?", Ponta Delgada, 7-8 de Junho de 2013.
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Tese de Doutoramento, Ciências do Mar, especialidade de Biologia Marinha, 18 de Dezembro de 2015, Universidade dos Açores.
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One of the most common characteristics of Portuguese littoral is the existence of a planed surface (the so-called "littoral platform"), situated at different altitudes and bordered from the inland by a straight relief, strongly contrasting with that planed surface. This one is generally covered with several outcrops of the so-called Plio-Pleistocene deposits. Till the eighties this platform has been interpreted as stable staircase of old marine levels, registering in a passive way the eustatic variations. The rigid step bordering it easterly should be a fossil cliff. However, our study has proved that many of these deposits have a continental origin. These continental deposits have fluvial or alluvial fan facies and they are lying above 40 meters. Marine deposits seem to be quite rare and they only occupy a small western area, beneath the altitude of 40 meters and developing into three different marine levels. There is a rigid step between the two kinds of deposits. We think that the clear geometric separation between these deposits together with this rigid step, indicates a tectonic origin. It seems that the sea must have touched only the western part of this surface, when neotectonic movements lowered it down. There are more evidences for neotectonic movements: a) there are faults (mainly inverse faults) affecting the higher deposits of this littoral platform; b) the same marine level seems to appear at different altitudes, developing an irregular pattern with a general trend dipping from the North to the South.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil Engenharia Ecológica
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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil Engenharia Ecológica