Dissertations / Theses on the topic 'Bivalve'
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1
Reynolds, David John. "Establishing multi-bivalve species sclerochronology." Thesis, Bangor University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543214.
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Puinean, Alin Mirel. "Development of biomarkers of estrogen exposure in the marine bivalve Mytilus edulis Linnaeus (Mollusca : Bivalvia)." Thesis, University of Sussex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426316.
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Aucoin, Serge. "Écologie de population du bivalve Pinna carnea." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25177/25177.pdf.
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Mohammed, Saad Zakaria Mohammed. "Aspects of nursery cultivation of bivalve molluscs." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328163.
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Volpe, Enrico <1987>. "Finfish and Human Pathogens in Bivalve Molluscs." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8062/1/Tesi%20PhD_Volpe%20Enrico.pdf.
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Bivalve molluscs are an important food source for living beings, humans included. They are obligated filter feeders, that feed on microalgae, bacteria and organic particles present in the aquatic environment. Accordingly, they could accumulate chemical compounds, marine biotoxins, bacteria and viruses, including human and animal pathogens (Molloy et al., 2013; Serratore et al., 2014), influencing the epidemiology of animal and human infectious diseases (Skär & Mortensen, 2007).
This topic has been long investigated for human pathogens. On the other hand, poor studies were available for finfish pathogens.
The Ph.D thesis, arranged in three chapters, deals with finfish and human pathogens in bivalve molluscs and focus on betanodavirus presence in these invertebrates, on their interaction with the Redspotted grouper nervous necrosis virus (RGNNV), one species of the genus Betanodavirus, and the development of a method to mitigate bacterial and viral contaminations of bivalve molluscs.
Betanodaviruses very closely related to those of finfish have been found widely present in bivalve molluscs. The clams were demonstrated able to take up and then shed viable RGNNV into the surrounding environment through faeces and filtered water into the surrounding environment posing a serious risk for susceptible cohabitant fish species. Finally, a novel Manila clam sea water potassium MPS-based disinfection method was set up to mitigate the impact of bacterial and viral contaminations in bivalve molluscs.
The obtained results point out the possible role of bivalve molluscs in the transmission of pathogens to finfish and highlight the needing of surveillance and control activities where a close inter-specific contact is present. The proposed novel disinfection method provides good experimental results and could find wide application in fisheries sector after adequate field tests.
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Semba, Prasetiya Fiddy. "Greening phenomenon in bivalve by marennine produced from Haslea ostrearia and its consequences on bivalve’s integrated response." Thesis, Le Mans, 2015. http://www.theses.fr/2015LEMA1017/document.
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Le but de ce travail de doctorat est d’évaluer la possibilité d’utiliser Haslea ostrearia et la marennine en ostréiculture. Les objectives de ce projet sont : (1) l'évaluation du comportement alimentaire de l'huître creuse Crassostrea gigas sur des cellules d’H. ostrearia de différentes tailles et les conséquences potentielles sur les populations algales; (2) la caractérisation du verdissement par la marennine et ses conséquences sur la physiologie de C. gigas; (3) les conséquences du verdissement sur les traits comportementaux, physiologiques et biochimiques de plusieurs espèces de bivalves; (4) l'utilisation conjuguée d’H. ostrearia avec d'autres microalgues d’importance en aquaculture. Nos résultats suggèrent que la taille des cellules affecte considérablement le processus de selection d’H. ostrearia par l’huître. Cette étude démontre également que la forme extracellulaire de la marenninne contribue significativement au verdissement dans les mucocytes des branchies. Mis à part le verdissement des organes palléaux des bivalves, une concentration modérée de marennine (2 mg L-1) affecte les performances comportementales, physiologiques et biochimiques des bivalves. Néanmoins, ces effets pourraient être compensés par ses activités biologiques comme agent antibactérien naturel et source d’alimentation mixte d’algues en conchylicultureThis Ph.D. thesis focuses on several assessments to achieve the optimum benefit of utilization of marennine in the field of aquaculture. The study covers: (1) the assessment in feeding behavior of the Pacific oyster Crassostrea gigas on different sizes of Haslea ostrearia and its ecological consequence; (2) the characterization of the greening by marennine and its consequences on some physiological traits of on C. gigas. (3) the consequence of greening by marennine on behavioral, physiological and biochemical traits of bivalves; (4) the utilization of H. ostrearia and marennine in a combination diet with other microalgae relevant to aquaculture.Our results suggest that cell size impacts considerably the selection process of H. ostrearia by oyster. This study also demonstrates that the extracellular form of marennine contributes significantly to the greening in the mucocytes of the gills. Apart from greening the pallial organs of bivalves, marennine (2 mg L-1) affects the behavioural, physiological and biochemical performance. Nevertheless, these effects can be compensated for its biological activities such as natural antibacterial agent and use as a mixed algal diet for bivalve aquaculture
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Trigg, Colin. "Ecological studies on the bivalve Limaria hians (Gmelin)." Thesis, Heriot-Watt University, 2009. http://hdl.handle.net/10399/2312.
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Several ecological studies were carried out on the bivalve Limaria hians and the biogenic beds created by their byssal threads. Specimens used were collected from two populations located on the west coast of Scotland. Age, growth and population dynamics were analysed using several methods. Limaria hians were tagged using plastic tags or the chemical dye calcein, left for 1 year and growth marks in the chondrophore counted. To establish growth parameters marked or caged L. hians were placed in situ and examined after 1 and 2 years. In addition, quantitative collections of L. hians were made from the field every 2 months over an 18 month period, their length measured and numbers recorded. Sub-samples from these collections were used to analyse the sex ratio of the populations. It was found that a single annual growth mark was deposited in the winter and age could be determined by counting chondrophore growth marks; giving a maximum age of 10 years. Measurements of growth using different techniques gave a growth performance index between 2.51 and 2.61. Spawning of L. hians occurred in May and June resulting in peak settlement during July and August. A significant change in sex ratio with respect to shell length was found, indicating protandry. Indirect examination of age was attempted using stable isotopic analysis of δ18O and δ13C contained within the shell. To overcome difficulties found with the stable isotope technique, laser ablation mass spectrometry analysis was used to measure the ratios of trace elements. Two specimens each had a single valve placed in epoxy resin. Sequential lines were drilled along the surface of the valves and the carbonate gathered for analysis by mass spectrometry. From the remaining valve of each specimen a thin section was prepared and laser ablation performed. Limaria hians incorporated δ18O in equilibrium with the surrounding sea water allowing an estimation of ambient temperature at times of shell deposition. A sinusoidal pattern was seen in the isotopic analysis, yet it was not possible to accurately age the specimens by this method, although the approximate time of year when growth mark deposition occurred was obtained. A relationship was seen between the trace element Mg and seawater temperature; however, it is not believed that Mg/Ca ratios in L. hians can be used as a proxy for sea temperatures. Use of these techniques with L. hians is considered limited on account of the animal’s thin and friable shell. An investigation to determine the biodiversity of L. hians beds was carried out for two populations during the winter and summer periods. Cores were taken semi-randomly and the organisms removed from the nest material. Flora and fauna were identified and where possible enumerated. Univariate and multivariate analyses of the data investigated any differences between sites and times. A total of 283 species were found consisting of 16 phyla. Univariate analysis revealed significant differences between the species richness of the two populations, whilst multivariate analysis illustrated differences in the assemblage compositions between sites and times. This study indicated that, in terms of richness and diversity, L. hians beds are at least as rich as horse mussel and serpulid reefs. The rate of regrowth of L. hians nest material, following a simulated dredging impact was examined on an extensive L. hians bed. Within an area of complete coverage of the sea bed by a turf of L. hians nest material, the turf was cleared by diver from 10 0.25 m2 replicate plots and the sediment subsequently raked to simulate the passage of a scallop dredge. The areal extent and pattern of nest regrowth was recorded after 6 and 12 months. Over the initial 6 autumn and winter months treatment plots displayed a mean regrowth of 9.2% of the cleared area, increasing to 15% in the second 6 month spring and summer period. However, no significant difference in growth was found between these periods. After 12 months half the treatment plots exhibited <25% nest cover and none of them contained nest of a thickness comparable to the surrounding bed. Conversion of regrowth rates within the treated plots to the rate of nest advance along a linear front, gave a value of 3.2 cm per year, highlighting the susceptibility of this species-rich biotope to scallop dredging from which activity it may take a century to recover. The pressing need for the conservation status of this biotope to be reassessed is stressed. Its status as a biogenic reef should be accepted internationally and appropriate protective measures put in place.
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Liguori, Louis-Antoine. "La voie transgutéale digastrique bivalve : description, évaluation, critiques." Saint-Etienne, 1995. http://www.theses.fr/1995STET6413.
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Casse, Nathalie. "Eléments d'embryologie de Pecten maximus L. (mollusque bivalve)." Brest, 1995. http://www.theses.fr/1995BRES2009.
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Le developpement embryonnaire de pecten maximus est decrit depuis l'uf jusqu'a la larve d qui apparait 45 heures apres la fecondation, a la temperature de 18-19c. Les deux premieres divisions de segmentation sont accompagnees par la formation d'un lobe polaire au pole vegetatif de l'embryon. Les stades morula et blastula apparaissent, respectivement 5 et 7 heures apres la fecondation. La gastrulation conjugue les mouvements d'epibolie et d'embolie, elle s'effectue entre 8 et 12 heures de developpement. Elle produit une larve ciliee et nageuse. A la 20eme heure, la larve est une trochophore. La prototroque consiste en une couronne de cils denses, disposes irregulierement ; la region pretrochale porte un long flagelle apical. L'archenteron se developpe, la bouche est ouverte sous la prototroque au niveau de la region ventrale de la larve. De plus, une fine pellicule emerge de l'invagination de la region coquilliere (irc). Chez les larves agees de 26 heures, la cavite viscerale se forme, le tractus digestif possede l'sophage, l'estomac et l'intestin ; la prototroque va progressivement devenir le velum. Apres 30 heures de developpement, la larve a atteint le stade veligere. Le bord du velum presente 4 anneaux ciliaires. L'epithelium coquillier est devenu le manteau larvaire dont le bord secrete la pellicule coquilliere. Les larves d sont observees a 45 heures, leur coquille est calcifiee et recouvre tout le corps de l'animal. Le tractus digestif est complet et contient une grande quantite de bacteries. Les variations des quantites de proteines, lipides et glucides totaux sont etudiees pendant la periode embryonnaire. Deux phases sont distinguees: de 2 a 24 heures, les lipides sont consommes par les larves ; a l'inverse, de 24 a 42 heures, une augmentation des quantites des differents composes est observee
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Santos, Gabriel Luiz dos. "Determinação multielementar e análise de especiação de vanádio em amostras ambientais da Baía de Todos os Santos, Bahia, Brasil, por técnicas espectrométricas." Instituto de Química, 2013. http://repositorio.ufba.br/ri/handle/ri/15803.
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CNPq
O presente trabalho realizado em amostras coletadas na Baía de Todos os Santos, Bahia, Brasil, propõe estratégias para determinação multielementar e análise de especiação de vanádio em amostras de moluscos bivalves e sedimentos, empregando ICP OES e ICP-MS. Na primeira parte da tese, foram avaliadas as potencialidades de dois espectrômetros de massa com plasma indutivamente acoplado para determinação de As, Cr, Ni, Se e V em amostras de moluscos bivalves. Para efeito de comparação, três materiais de referência certificados (CRM) foram analisados: NIST 1566b SRM Oyster tissue, NRCC TORT-2 Lobster Hepatopancreas e NIST 2977 SRM Mussel tissue. A condição recomendada, que consistiu na determinação no modo padrão com adição de padrão interno, foi aplicada na determinação dos analitos em amostras de Macoma constricta coletadas em diferentes regiões da BTS. Os resultados apontaram que a maioria dos níveis de As, Cr, Ni, Se e V presentes na espécie Macoma constricta apresentaram valores acima dos níveis estabelecidos pela legislação vigente brasileira que são: 1,0 (As); 0,1 (Cr); 5,0 (Ni); 0,3 (Se) e 0,77 (V) g g-1 (peso úmido), o que representa risco à população e ao ecossistema. Na segunda parte da tese, foram investigadas as condições para a análise de especiação de vanádio em amostras de sedimentos, empregando extração alcalina e determinação por ICP OES. A concentração de V(IV) foi determinada por diferença, considerando a determinação de vanádio total, também realizada por ICP OES, após digestão das amostras com ácido nítrico em forno de micro- ondas com cavidade, usando o procedimento EPA 3051A. O procedimento foi validado através de testes de adição e recuperação e de análise do seguinte material de referência certificado: NIST 2702 (Inorganics in marine sediment). Pelos resultados obtidos pode-se concluir que os compostos contendo V(IV) são mais dominantes nas amostras dos sedimentos analisados.
The present work conducted on samples collected in Todos os Santos Bay, Bahia, Brasil, proposes strategies for multielement determination and speciation analysis of vanadium in bivalve molluscs and sediments samples, using ICP OES and ICP-MS. In the first part of the thesis, the potential of two inductively coupled plasma mass spectrometers for determination of As, Cr, Ni, Se and V in bivalve molluscs samples were evaluated. For comparison, three certified reference materials (CRM) were analyzed: NIST 1566b SRM Oyster tissue, NRCC TORT-2 Lobster Hepatopancreas e NIST 2977 SRM Mussel tissue. The recommended condition, which consisted in determining the standard mode with addition of internal standard, was applied in the determination of analytes in samples of Macoma constricta collected in different regions of the BTS. The results showed that most levels of As, Cr, Ni, Se and V present in the species Macoma constricta have values above the levels established by the Brazilian legislation, that are: 1.0 (As); 0.1 (Cr); 5.0 (Ni); 0.3 (Se) and 0.77 (V) g g-1 (wet weight), which represents risk to the population and the ecosystem. In the second part of the thesis, the conditions for speciation analysis of vanadium in soil and sediment samples were investigated, using alkaline extraction and determining by ICP OES. The V (IV) concentration was determined by difference, considering the total vanadium determination, also performed by ICP OES, after the samples digestion with nitric acid in cavity microwave oven, using the procedure EPA 3051A. The procedure was validated through addition and recovery tests and analysis of the following certified reference material: NIST 2702 (Inorganics in marine sediment). From the obtained results it can be concluded that compounds containing V (IV) are majority in the sediment samples analyzed.
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Leite, Mayla Monique dos Santos. "Desenvolvimento de ling?i?a de mexilh?o (Perna perna) funcional processada com a aplica??o de transglutaminase microbiana." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/1672.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
The difficulty in supplying the animal protein demand of great biological value for the human population is a major concern of our century. Reports of Food Agriculture Organization (FAO) show the rapid world population growth as a major contributing factor to the increased need in the production and diversification of protein foods worldwide. FAO estimates report that in 2050 the number of people will reach about 9.6 billion people and will need to ensure food security with sustainable development. In this context, the objective of this study was to develop a prebiotic built by the addition of inulin in the form of cooked type sausage, the base of mussels (Perna, Linnaeus 1758), processed with microbial transglutaminase (MTGase) for diversification of products based fish and evaluate the influence of this enzyme in the texture of the final product and its behavior for mussels meat since the majority of studies are in beef and pork. The sausages were developed from the ground meat of mussels (CTM), where both the raw material as the products presented physicochemical and microbiological characteristics satisfactory and showed good nutritional value, highlighting the protein content and low lipid content of the product. To evaluate the best answers in the preparation of sausages was used Delineation Composite Central Rotational with the independent variables: percentage of water (5-30%), concentration of Inulin (0-3%) and concentration of MTGase (0-2%) and dependent: moisture content, water holding capacity (WHC) and percentage of income and shrinking of sausages in cooking and instrumental texture. Any water, as inulin and MTGase influenced significantly (p <0.05) in the range of concentrations studied, in variable responses% humidity and WHC, however, for the variables yields and% shrinkage during cooking and instrumental texture in the study group, there was no significant influence (p> 0.05). The proposed design has shown that the best results were obtained for the lower water concentrations and MTGase and inulin in the formulation. So they were prepared sausages mussels with 0.5%, 1.0% and 1.5% MTGase and water percentage (5%) and Inulin (3% - specification of legislation for the product to be considered prebiotic) set for prediction of the mathematical model. It was concluded that the model fits to obtain moisture content of the response and WHC very similar to those obtained in practice, which can provide the best moisture content for different concentrations of transglutaminase for sausages formulations based pre mussels cooked.
A dificuldade em suprir a demanda de prote?na de origem animal de excelente valor biol?gico para a popula??o humana ? uma das maiores preocupa??es do nosso s?culo. Relat?rios da Food Agriculture Organization (FAO) apontam o r?pido crescimento demogr?fico mundial como um dos principais fatores contribuintes para o aumento da necessidade na produ??o e diversifica??o de alimentos proteicos em todo mundo. Estimativas da FAO descrevem que em 2050 o contingente de pessoas atingir? cerca de 9,6 bilh?es de indiv?duos e ser? necess?rio garantir a seguran?a alimentar juntamente com desenvolvimento sustent?vel. Neste contexto, o objetivo do presente estudo foi desenvolver um embutido prebi?tico pela adi??o de inulina, na forma de lingui?a tipo cozida, a base de mexilh?es (Perna perna, Linnaeus 1758), processado com transglutaminase microbiana (MTGase) para diversifica??o de produtos a base de pescado e avaliar a influ?ncia desta enzima na textura do produto final e o seu comportamento para a carne de mexilh?es, visto que a maioria dos estudos realizados s?o com carne bovina ou su?na. As lingui?as foram desenvolvidas a partir da carne triturada de mexilh?es (CTM), onde tanto a mat?ria prima quanto a lingui?a apresentaram caracter?sticas f?sico-qu?micas e microbiol?gicas satisfat?rias e apresentaram bom valor nutricional, destacando o teor proteico e baixo teor de lip?deo do produto. Para avaliar as melhores respostas na elabora??o das lingui?as foi utilizado Delineamento Composto Central Rotacional, com as vari?veis independentes: percentual de ?gua (5 a 30%), concentra??o de Inulina (0 a 3%) e concentra??o de MTGase (0 a 2%) e as vari?veis dependentes: teor de umidade, capacidade de reten??o de ?gua (CRA) e percentuais de rendimento e encolhimento das lingui?as na coc??o e textura instrumental. Tanto a ?gua, quanto a inulina e a MTGase, influenciaram de forma significativa (p<0,05), na faixa de concentra??es estudada, nas vari?veis respostas % Umidade e CRA, no entanto, para as vari?veis respostas % rendimento e encolhimento na coc??o e textura instrumental, na faixa estudada, n?o houve influ?ncia significativa (p>0,05). O delineamento proposto evidenciou que os melhores resultados foram obtidos para as menores concentra??es de ?gua e MTGase e Inulina na formula??o. Assim, foram elaboradas lingui?as de mexilh?es com 0,5%, 1,0% e 1,5% de MTGase e os percentuais de ?gua (5%) e de Inulina (3% - especifica??o da legisla??o para o produto ser considerado prebi?tico) fixados para predi??o do modelo matem?tico. Concluiu-se que o modelo se ajusta para a obten??o de respostas do teor de umidade e CRA muito similares ?s obtidas na pr?tica, onde pode se prever o melhor teor de umidade para diferentes concentra??es da enzima transglutaminase para formula??es de lingui?as a base de mexilh?es pr?-cozidos
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Myers, Amanda R. ""Recirculating aquaculture system integration of bivalve culture for effluent nutrient composition reduction" /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/myersa/amandamyers.pdf.
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Sartori, André Fernando. "Anatomia do bivalve antártico Thracia meridionalis Smith, 1885 (Anomalodesmata:Thraciidae)." Connect to this title online, 2003. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-19092004-192817/.
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Baker, Patrick Kelly. "Quantification of settlement and recruitment processes in bivalve mollusks." W&M ScholarWorks, 1994. https://scholarworks.wm.edu/etd/1539616555.
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Studies were carried out to quantify abundance, mortality, and variability in these parameters, during settlement and recruitment of bivalve mollusks, using the oyster, Crassostrea virginica, as a primary model species. Most work was undertaken in the York River, Chesapeake Bay, Virginia, with additional work in the Indian River, Florida. The period chosen, in the bivalve early life history, was from the late planktonic larva to the early benthic juvenile. Studies were designed to specifically examine (a) abundance of late-stage larvae in the plankton, (b) the relationship between larval abundance and settlement, and (c) mortality immediately following settlement. Variability in abundance or mortality was also examined at each of these stages. It was found that, of larvae in the plankton with the morphological characteristics of competency-to-settle, about 80% would settle within 24 hours, under laboratory conditions. Temporal variation in abundance of planktonic larvae was high and apparently random, but separate species covaried in observed abundance. Time of day and tidal phase had little or no effect on larval distribution, but late stage larvae showed a consistent depth preference, which varied depending on species. Crassostrea late larvae tended to be most abundant near the benthos, both at the Virginia site and at the Florida site. The relationship between planktonic abundance and settlement density of Crassostrea was weak, within one order of magnitude of variation in larval abundance, although the same relationship for a sympatric species in Florida, Ostrea equestris, was significant. Settlement onto a natural oyster reef was more variable but not significantly lower than settlement onto adjacent defaunated shell substrate. The increased variability could not be accounted for by coverage by dominant fouling macroorganisms. Mortality of newly-settled juvenile Crassostrea was high, with near 100% mortality within 28 days on a natural oyster reef, with high but significantly lower (about 96%) mortality on previously defaunated shell substrate over the same time.
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JONES, DONNA CARLSON. "BIVALVE EPIBIONT ARMOR: THE EVOLUTION OF AN ANTIPREDATORY STRATEGY." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1085085950.
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Jennions, Suzanne M. "The effect of environmental change on bivalve mollusc biomineralisation." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685038.
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Anthropogenic C02 release is leading to a wide range of oceanic environmental changes that may influence the survivability of marine organisms in the future. Environmental change varies regionally, and Southern Ocean calcifying organisms are considered to be particularly at risk from change, due to low pre-existing pH conditions and rapidly increasing temperatures. UVic model data from the Southern Ocean is used to assess environmental change in the region, and shows the importance of considering the variability as well as the magnitude of change. Since pre-industrialisation, the four Southern Ocean locations analysed showed a modern pH range entirely outside the historic range. The southern west Antarctic Peninsula region is considered the most vulnerable due to historic environmental stability, increased variability in the modern, and the widest gap between historic and modern carbonate chemistry variability envelops. The geochemistry and crystal structure of eight species of Antarctic bivalves were investigated, and four of these species were used to assess organism response to environmental change since pre-industrialisation from the western Antarctic Peninsula to South Georgia. Bivalve response varied between and within species: Lissarca miliaris showed a decrease in shell robustness over time; Lissarca notorcadensis showed one instance of no change and another of increased robustness; and Limatula pygmaealLimatula ovalis showed no change. There was no correlation between sites identified as vulnerable in the UVic model, and bivalve response. Mytilus californianus, a temperate bivalve species, from Tatoosh Island on the NW Pacific coastline of the USA, were similarly tested as pH has declined in the region four times faster than the global average. Bivalve shells showed a change in biomineralisation, resulting in increased robustness from the historic to the modern. The variability in response illustrates that some species have sufficient plasticity to be unaffected by environmental change, some may struggle to survive in future oceans and others have the capacity to adapt on short timescales.
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Dufour, Suzanne Carole. "Adaptations to chemoautotrophic symbiosis in the bivalve family Thyasiridae /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2003. http://wwwlib.umi.com/cr/ucsd/fullcit?p3112875.
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Tong, Lily K. Y. (Lily Kit Ying). "The population ecology of the intertidal bivalve Lasaea australis." Phd thesis, Faculty of Arts, 1990. http://hdl.handle.net/2123/9035.
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Gussman, David S. "The use of brewers condensed solubles in bivalve mariculture." W&M ScholarWorks, 1987. https://scholarworks.wm.edu/etd/1539616677.
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Brewers Condensed Solubles (BCS), a by-product of the brewing industry, was evaluated as a nutrient source for rearing juvenile oysters (Crassostrea virginica) and clams (Mercenaria mercenaria). The BCS was used to culture bacteria which were fed to colorless flagellates which were in turn fed to the oysters and clams. The overall growth efficiency of oysters on BCS was 473 mg of oyster (whole weight) per g of BCS (dry weight). Fourteen isolates representing nine genera of bacteria were isolated from BCS enrichment cultures. Specific growth rates of the isolates at &24\sp\circ{lcub}\rm C{rcub}& on a BCS medium ranged from 0.48 &{lcub}\rm h\sp{lcub}-1{rcub}{rcub}& to 0.11 &{lcub}\rm h\sp{lcub}-1{rcub}{rcub}.& The conversion of BCS to bacterial biomass was examined for four isolates with supplements of 0, 38, 76, and 152 mg/l of ammonium sulfate. The largest bacterial biomass (127 mg/g BCS) was obtained with Pseudomonas marina. The largest bacterial biomass when averaged over all bacterial isolates was obtained with 38 mg/l of ammonium sulfate. Yields of P. marina on BCS ranged from 27.4% for no ammonium sulfate addition to 38.5% with 38 mg/l of ammonium sulfate. The effects of dissolved nutrients, salinity, temperature, shaking, bacterial concentration, and bacterial species on the growth rates of five species of colorless flagellates were examined. None of the colorless flagellates could be raised on the dissolved nutrients in BCS, all required a bacterial diet. Shaking, salinity, and the bacterial isolate used as food had little effect on the flagellate growth rates. Temperature and bacterial concentration had pronounced effects. The greatest growth rates were recorded at temperatures between 21 and &26\sp\circ{lcub}\rm C{rcub}.& Growth rates increased with increasing bacterial concentration in a manner suggestive of Michaelis-Menten kinetics. Maximum specific growth rates ranged from 0.11 &{lcub}\rm h\sp{lcub}-1{rcub}{rcub}& to 0.16 &{lcub}\rm h\sp{lcub}-1{rcub}{rcub}.& Yields of colorless flagellates growing on bacteria ranged from 0.30 to 0.42. The growth of oysters and clams fed colorless flagellates. BCS enrichment cultures, and bacteria was compared to the growth of starved controls and animals fed Tetraselmis suecica. Paraphysomonas vestita was the only species of colorless flagellate to consistently result in growth greater than the starved control. The BCS enrichment culture varied greatly in its nutritional value. The average oyster growth on P. vestita was 55% of the growth obtained with T. suecica. Oysters fed combinations of T. suecica and P. vestita did not grow as rapidly as on a pure diet of T. suecica. No growth occurred when oysters and clams were fed a purely bacterial diet.
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Araujo, Maria Lucia Rodrigues. "Ciclo reprodutivo e densidade populacional de Anomalocardia brasiliana (GMELIN, 1791) (mollusca: bivalvia: veneriidae) na praia do Canto da Barra, Fortim, CearÃ." Universidade Federal do CearÃ, 2004. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3239.
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Os bivalves marinhos sÃo muitos apreciados como alimento e no aproveitamento de suas conchas para vÃrias utilidades especialmente como enfeites. A presente pesquisa teve como objetivo estudar o bivalve marinho venerÃdeo Anomalocardia brasiliana, quanto a densidade populacional e ciclo de reproduÃÃo, correlacionando este Ãltimo aos parÃmetros ambientais (salinidade, temperatura e precipitaÃÃo pluviomÃtrica). As amostragens foram realizadas mensalmente durante o perÃodo de maio/02 a abril/03, na praia do Canto da Barra, municÃpio de Fortim â CE, no estuÃrio do Rio Jaguaribe. Os indivÃduos Anomalocardia brasiliana apresentaram um padrÃo de distribuiÃÃo bem caracterÃstico, com os juvenis concentrados em Ãrea com sedimento fino e mais Ãmido e os adultos em banco arenosos com sedimento mais grosseiro. A diferenciaÃÃo sexual ocorreu provavelmente entre 12,6mm e 17,9mm de comprimento de conchas. A identificaÃÃo dos sexos foi realizada utilizando-se tÃcnicas histolÃgicas de rotina. Durante a gametogÃnese, foram reconhecidas em fÃmeas, ovogÃnias, ovÃcitos prÃ-vitelogÃnicos, ovÃcitos vitelogÃnicos e ovÃcitos maduros, e, em machos, espermatogÃnias, espermatÃcitos I, espematÃcitos II, espermÃtides e espermatozÃides. A reproduÃÃo da espÃcie à contÃnua, entretanto foram observados perÃodos de maior liberaÃÃo de gametas de julho a outubro/2002 e de fevereiro a abril/2003. O ciclo reprodutivo caracterizou-se pelas seguintes as fases do desenvolvimento gonadal: âem MaturaÃÃoâ, âMaduroâ, âem EliminaÃÃoâ, âEliminadoâ, para ambos os sexos. Dentre os fatores ambientais observados neste estudo, a precipitaÃÃo pluviomÃtrica e a salinidade foram as que apresentaram as maiores amplitudes de variaÃÃo. Entretanto, uma influÃncia significativa do efeito da diminuiÃÃo da salinidade foi observada somente em machos, provavelmente causada pela alta precipitaÃÃo pluviomÃtrica verificada em abril/03. Durante este estudo, observou-se a ocorrÃncia de parasitas do gÃnero Bucephalus sp. em 6,5% dos indivÃduos analisados. Apesar da baixa incidÃncia de organismos parasitados, a ocorrÃncia de parasitismo na populaÃÃo de Anomalocardia brasiliana, no estuÃrio do Rio Jaguaribe, alerta para necessidade de estudo sobre as condiÃÃes fisiolÃgicas desta espÃcie na regiÃo.Marine bivalves are very appreciated as food and its shell is used for several purposes, especially for ornament. The present research aims to study the marine bivalve Anomalocardia brasiliana in relation to its population density and reproductive cycle, correlating them with environmental parameters (salinity, temperature and precipitation). Monthly samplings were realized from May 2002 to April 2003 at Canto da Barra Beach, in the Jaguaribe River Estuary, Fortim, CearÃ. The Anomalocardia brasiliana individuals presented a quite characteristic distribution pattern, with the juvenile ones concentrated in areas with fine and moist sediment (fine sand) and the adult ones concentrated in sandy beds with coarse sediment (medium sand). Sexual differentiation probably occurred when the shell length was between 12,6mm and 17,9mm. Sex determination was realized using custom histological techniques. During gametogenesis, oogonia, previtellogenic oocytes, vitellogenic oocytes and mature oocytes were recognized in females, and spermatogonia, spermatocytes I, spermatocytes II, spermatids and spermatozoa were recognized in males. The reproductive cycle is continuous. Nevertheless, periods of intense gamete liberation were observed from July to October 2002 and form February to April 2003. For both sexes the reproduction cycle was characterized by the following stages in the development: âin Ripeningâ, âRipeâ, âin Spawningâ, âSpawnedâ. Among the environmental agents observed in this study, precipitation and salinity were the ones that presented the largest fluctuation in amplitude. However, a major influence by the salinity reduction effect was only observed in males, probably caused by the high precipitation registered in April 2003. During this study, the occurrence of parasites from the genus Bucephalus sp. was observed in 6,5% of the analyzed individuals. Despite the low influence of organisms infected with parasites, the occurrence of parasitism in the Anomalocardia brasiliana population at the Jaguaribe River Estuary alerts the necessity for further studies on the physiological conditions of this species in that area.
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Khamdan, S. A. A. "Aspects of reproduction and triploidy manipulation in the pearl oyster, Pinctada radiata (Leach)." Thesis, Bangor University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239889.
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Farias, Marcia Fernandes. "Ciclo reprodutivo, distribuição populacional e condições microbiologicas de Tagelus plebeius (Lighfoot, 1786) (MOLLUSCA: BIVALVIA: SOLECURTIDAE) no estuário do rio ceará em Fortaleza - Ce." reponame:Repositório Institucional da UFC, 2008. http://www.repositorio.ufc.br/handle/riufc/4913.
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FARIAS, Marcia Fernandes. Ciclo reprodutivo, distribuição populacional e condições microbiologicas de Tagelus plebeius (Lighfoot, 1786) (MOLLUSCA: BIVALVIA: SOLECURTIDAE) no estuário do rio ceará em Fortaleza-Ce. 2008. 152 f.: Dissertação (mestrado) - Universidade Federal do Ceará, Instituto de Ciências do Mar, Pós-Graduação em Ciências Marinhas Tropicais, 2008.Submitted by Solange Gomes (solagom@yahoo.com.br) on 2013-02-05T17:57:17Z No. of bitstreams: 1 Marcia Fernandes de Farias.pdf: 5911039 bytes, checksum: 2e0f1ed604f10c68fee4d10cca5b24d2 (MD5)
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Made available in DSpace on 2013-06-03T15:01:15Z (GMT). No. of bitstreams: 1 Marcia Fernandes de Farias.pdf: 5911039 bytes, checksum: 2e0f1ed604f10c68fee4d10cca5b24d2 (MD5) Previous issue date: 2008
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Paugam, Alain. "Identification immunologique des larves d'un mollusque bivalve marin : Pecten maximus." Brest, 2000. http://www.theses.fr/2000BRES2023.
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Pour comprendre les fluctuations d'abondance de certaines especes marines il est important de ne pas negliger leurs stades larvaires planctoniques. Les representants de ces organismes sont difficiles a identifier car les outils specifiques adaptes sont peu nombreux. L'objet de ce travail est de proposer, dans le cadre du pndr (programme national sur le determinisme du recrutement), une approche methodologique qui facilite la reconnaissance des larves de bivalves. L'espece cible est la coquille saint-jacques, pecten maximus et le site d'etude, la rade de brest (france). La voie suivie est immunologique. Parmi les molecules potentiellement immunogenes, les proteines sont retenues pour induire la production de serum anti-larves de pecten maximus. Ce choix necessite le developpement d'une technique d'extraction proteique adaptee aux echantillons larvaires de bivalves marins. Les extraits proteiques obtenus a partir de differentes especes sont analyses en electrophorese sds-page et sont specifiques. Ils permettent de tester analytiquement, en immunotransfert, la specificite des serums anti-extrait proteique larvaire de ce pectinide. Ces serums reagissent fortement vis a vis de l'extrait proteique de larves de pecten maximus mais presentent egalement de nombreuses reponses croisees vis a vis des extraits proteiques appartenant aux autres especes etudiees (aequipecten opercularis, chlamys varia, ostrea edulis, crassostrea gigas, ruditapes decussatus, ruditapes philippinarum, mytilus edulis). Differentes solutions sont envisagees pour reduire le taux de reponses croisees. L'epuisement des serums contre des extraits proteiques de crassostrea gigas permet d'eliminer la quasi-totalite de ces reponses sans nuire a la reconnaissance des extraits proteiques de pecten maximus. Ces serums epuises sont utilises directement contre des lots de larves de bivalves pour valider leur pouvoir de reconnaissance des larves de pecten maximus. Trois marqueurs secondaires destines a la reconnaissance du couple larve de pecten maximus/anticorps sont testes : la phosphatase alcaline, les billes magnetiques (dynal), la fluorescence (fitc). La fluorescence donne les meilleurs resultats et c'est cette technique qui est retenue et mise en application pour permettre de visualiser les larves de pecten maximus contenues dans des echantillons de plancton en provenance de la rade de brest. Ce dernier aspect de l'etude permet sur une annee, d'identifier des larves de pecten maximus en rade de brest et de retrouver une concordance certaine entre la presence de ces larves et les phases de reproduction des adultes. L'outil immunologique detecte les larves de pecten maximus parmi les autres organismes planctoniques et pourrait etre developpe pour de nombreuses especes a condition de disposer de quantite d'extrait proteique monospecifique suffisante pour induire la production d'anticorps.
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Huang, Zhenzhen 1982. "Experimental assessment of early diagenetic changes in marine bivalve shells." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98727.
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To study the influence of early diagenesis, left valves of fresh cultured bivalves (Mytilus edulis) were deployed in the natural environments (Panama, Barbados and New Brunswick), and right valves were kept in the laboratory as the controls. After 9 days, 8 months and 1 year, the retrieved shells have shown different macroscopic changes in weight, shell area, colour and luster. The microstructure of nacre shows organic matrix maceration, dissolution on the edges of tablets, and abiotic CaC03 reprecipitation on the surface and edges of nacre tablets. High-precision analyses of their carbon and oxygen stable isotope ratios show bulk differences of up to 0.4%o between experimental and control valves within 1 year. Results therefore indicate that early diagenesis can start very quickly post-mortem, and the nature of these changes varies with burial environments.
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Barnes, Penelope Anne Gee. "Eco-physiology of the endosymbiont-bearing lucinid bivalve, Codakia orbiculata." Thesis, University of Plymouth, 1993. http://hdl.handle.net/10026.1/1081.
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The lucinid bivalve Codakia orbiculata, whose gills contain sulphur-oxidizing symbiotic bacteria, occurs in high densities (500/m2) in the rhizosphere of shallow-water Thalassia testudinum sediments in Bermuda. Both sulphide and thiosulphate stimulate aerobic respiration in the isolated bacterial symbionts of C. orbiculata. Sulphide and thiosulphate stimulate anaerobic ^^COa fixation in bacteria isolated from sulphur-starved bivalves. Interstitial water sulphide concentrations in the bivalves' habitat reach 300 pM, and sulphate-reduction rates are high, but thiosulphate concentrations are low (0.66-32.27 pM) . Thiosulphate supplied to the symbionts in vivo must be produced by sulphide oxidation, possibly by the host bivalve. Isolated symbionts also respire aerobically and fix i * C02 in the absence of exogenous reduced sulphur, suggesting utilization of intracellular elemental sulphur stores. Codakia orbiculata symbiotic bacteria are able to respire nitrate. Nitrate concentrations in the interstitial water of C. orbiculata habitat can reach 36 pM. Thiosulphate stimulates nitrate respiration in the intact symbiosis, incubated in oxic and anoxic conditions, and in anoxic incubations of isolated symbionts. Intracellular elemental sulphur is also used by the •bacteria as a substrate in nitrate respiration. Nitrate respiration in the absence of exogenous nitrate suggests that the sjnnbionts may have a limited ability to store nitrate. There is no direct evidence that sulphide stimulates nitrate respiration in either the isolated symbionts or the intact symbiosis, incubated in anoxic conditions. Nitrite respiration in the symbionts is stimulated by sulphide (only), however. Because nitrate respiration was measured by nitrite accumulation, complete denitrification would explain the apparent failure of sulphide to stimulate nitrate respiration. High nitrate respiration rates in the intact symbiosis, incubated with sulphide in oxic conditions, may be in response to thiosulphate, supplied to the bacterial symbionts after host oxidation of sulphide. Nitrite respiration in the intact symbiosis, even when incubated in oxic conditions, demonstrates that the symbionts have access to some sulphide in vivo, however, and that host sulphide-oxidation may not be- 100% efficient. Nitrate and nitrite respiration in the intact symbiosis, even when incubated in oxic conditions, suggests that the bacteria may be exposed to low oxygen levels in vivo and may require the ability to utilize an alternate electron acceptor. Like some free - living bacteria , Codakia orbiculata bacterial symbionts may co-respire, or alternately respire , oxygen and nitrate . The Thalassia testudinum sediments in Bermuda may be ideal for this bacteria-bivalve symbiosis due to the availability of oxygen, nitrate and sulphide.
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Henshilwood, Kathleen. "The detection of food-borne viruses in bivalve molluscan shellfish." Thesis, University of Surrey, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367689.
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Ripley, Bonnie J. (Bonnie Jo) 1970. "Life history traits and population processes in marine bivalve molluscs." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47425.
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Sartori, André Fernando. "Anatomia do bivalve antártico Thracia meridionalis Smith, 1885 (Anomalodesmata: Thraciidae)." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-19092004-192817/.
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Thraciidae é uma das famílias de Anomalodesmata menos estudadas, dentre as quatorze que compõem a subclasse. Das cerca de trinta espécies atribuídas à família, apenas Trigonothracia jinxingae teve sua biologia e anatomia examinadas em detalhes; para outros Thraciidae, há pouca ou nenhuma informação morfológica, o que dificulta o entendimento das relações filogenéticas dentre os Anomalodesmata. Thracia meridionalis, única representante da família em águas antárticas, é aqui analisada sob o ponto de vista da anatomia, buscando iniciar o entendimento da biologia da espécie, bem como aprofundar os conhecimentos acerca do gênero Thracia e família Thraciidae, indispensáveis para a elucidação das relações evolutivas dentre os Anomalodesmata. A investigação detalhada da concha, sifões, e das estruturas e órgãos que compõem a cavidade palial e massa visceral foi realizada utilizando-se técnicas de dissecção, histologia e microscopia eletrônica de varredura. A concha é fina, inequivalve, ornamentada por grânulos periostracais calcificados, e dotada de charneira edêntula, ligamento secundário e primário, este último com litodesma presente apenas em indivíduos jovens. O manto tem margens extensivamente fundidas, com curta abertura pediosa, quarta abertura palial reduzida e sifões longos, separados, originando-se exclusivamente das pregas internas; as glândulas hipobranquiais são assimétricas, porém restritas à câmara infra-branquial, o que distingue T. meridionalis dentre os Anomalodesmata. Os ctenídios são extensos, heterorrábdicos e do tipo E de Atkins; uma ampla abertura entre os eixos dos ctenídios e o septo que separa as aberturas proximais dos sifões permite a comunicação entre as câmaras infra e supra-branquiais. A associação entre os palpos labiais e ctenídios pertence à categoria III de Stasek, e os estatocistos são do tipo B3 de Morton, este tipo constituindo novo registro para os Thracioidea. O estômago do tipo IV na classificação de Purchon é extensivamente provido de áreas de triagem, sugerindo que o animal ingere grande quantidade de partículas, o que é corroborado pelo intestino freqüentemente dilatado e repleto de fezes. T. meridionalis é hermafrodita simultâneo, com gônadas, gonodutos e gonóporos distintos. Grandes ovócitos (~200 µm) protegidos por espessa membrana vitelínica, e razão próxima de 0,75 entre os comprimentos das prodissoconchas I e II são indicativos de desenvolvimento larval lecitotrófico.The functional morphology of the Thraciidae is sparsely understood. Though several of its members had some morphological aspect described, only Trigonothracia jinxingae from Chinese waters is known in details, Thracia meridionalis being the first austral thraciid to be comprehensively reported upon. The latter species is the only representative of the family in Antarctic waters, and a common mud-dweller in the Admiralty Bay, King George Island, where living specimens were collected for the present study. T. meridionalis shares with Trigonothracia jinxingae many features that are typical of most Anomalodesmata: a secondary ligament of fused periostracum; extensively fused mantle margins; ctenidia of type E; ctenidial-labial palp junction of category III; stomach of type IV and simultaneous hermaphroditism. However, T. meridionalis is strikingly different from Trigonothracia in a number of aspects, as the presence of a fourth pallial aperture; statocysts of type B3; heterorhabdic ctenidia; a direct communication between the mantle chambers; deep-burrowing habit, the specimens lying on the left shell valve; siphons often retracted away from the sediment surface, protected within their mucous-lined burrows; stomach with extensive sorting areas; suspension-feeding habit; rectum passing over the kidneys and separate male and female gonadial apertures, thus revealing a greater diversity of form within the Thraciidae than is currently known.
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Grodzki, Marco <1980>. "Evaluation of Microbial Contamination in Bivalve Mollusks: Epidemiology and Diagnosis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4834/1/grodzki_marco_tesi.pdf.
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Shellfish are filter-feeding organisms that can accumulate many bacteria and viruses. Considering that depuration procedures are not effective in removal of certain microorganisms, shellfish-borne diseases are frequent in many parts of the world, and their control must rely primarily on investigation of prevalence of human pathogens in shellfish and water environment. However, the diffusion of enteric viruses and Vibrio bacteria is not known in many geographical areas, for example in Sardinia, Italy.
A survey aimed at investigating the prevalence of Norovirus (NoV), hepatitis A virus (HAV), V. parahaemolyticus, V. cholerae and V. vulnificus was carried out, analyzing both local and imported purified, non-purified and retail shellfish from North Italy and Sardinia. Shellfish from both areas were found contaminated by NoVs, HAV and Vibrio, including retail and purified animals. Molecular analysis evidenced different NoV genogroups and genotypes, including bovine NoVs, as well as pathogenic Vibrio strains, underlining the risk for shellfish consumers.
However, also other approaches are needed to control the diffusion of shellfish-borne diseases.
It was originally thought that enteric viruses are passively accumulated by shellfish. Recently, it was proven that NoVs bind to specific carbohydrate ligands in oysters, and various NoV strains are characterized by a different bioaccumulation pattern. To deepen the knowledge on this argument, a study was carried out, analyzing bioaccumulation of up to 8 different NoV strains in four different species of shellfish. Different bioaccumulation patterns were observed for each shellfish species and NoV strain used, potentially important in setting up effective shellfish purification protocols.
Finally, a novel study of evaluation of viral contamination in shellfish from the French Atlantic coast was carried out following the passage of Xynthia tempest over Western Europe which caused massive destruction. Different enteric viruses were found over a one month period, evidencing the potential of these events of contaminating shellfish.
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Grodzki, Marco <1980>. "Evaluation of Microbial Contamination in Bivalve Mollusks: Epidemiology and Diagnosis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4834/.
Full textAbstract:
Shellfish are filter-feeding organisms that can accumulate many bacteria and viruses. Considering that depuration procedures are not effective in removal of certain microorganisms, shellfish-borne diseases are frequent in many parts of the world, and their control must rely primarily on investigation of prevalence of human pathogens in shellfish and water environment. However, the diffusion of enteric viruses and Vibrio bacteria is not known in many geographical areas, for example in Sardinia, Italy.
A survey aimed at investigating the prevalence of Norovirus (NoV), hepatitis A virus (HAV), V. parahaemolyticus, V. cholerae and V. vulnificus was carried out, analyzing both local and imported purified, non-purified and retail shellfish from North Italy and Sardinia. Shellfish from both areas were found contaminated by NoVs, HAV and Vibrio, including retail and purified animals. Molecular analysis evidenced different NoV genogroups and genotypes, including bovine NoVs, as well as pathogenic Vibrio strains, underlining the risk for shellfish consumers.
However, also other approaches are needed to control the diffusion of shellfish-borne diseases.
It was originally thought that enteric viruses are passively accumulated by shellfish. Recently, it was proven that NoVs bind to specific carbohydrate ligands in oysters, and various NoV strains are characterized by a different bioaccumulation pattern. To deepen the knowledge on this argument, a study was carried out, analyzing bioaccumulation of up to 8 different NoV strains in four different species of shellfish. Different bioaccumulation patterns were observed for each shellfish species and NoV strain used, potentially important in setting up effective shellfish purification protocols.
Finally, a novel study of evaluation of viral contamination in shellfish from the French Atlantic coast was carried out following the passage of Xynthia tempest over Western Europe which caused massive destruction. Different enteric viruses were found over a one month period, evidencing the potential of these events of contaminating shellfish.
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Matte, Glavur Rogerio. "Isolamento de vibrios potencialmente patogênicos em moluscos bivalves." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-14072016-152410/.
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Neste estudo, 26 amostras de ostras (Crassostrea gigas) comercializadas na cidade de São Paulo e em alguns pontos do litoral de São Paulo, e 36 amostras de mexilhões (Perna perna) colhidas mensalmente em 3 pontos do litoral de Ubatuba - SP, foram submetidas à pesquisa de vibrios potencialmente patogênicos. As amostras desses moluscos eram submetidas a enriquecimento em água peptonada alcalina sem cloreto de sódio e com 1 por cento de cloreto de sódio, e GSTB. O isolamento foi realizado em ágar TCBS. Colônias sacarose positivas e negativas, sugestivas de espécies de Vibrio foram identificadas presuntivamente em meio de ágar ferro de Kligler, sendo confirmadas através de provas bioqufmicas complementares. Uma parte das amostras de vibrios potencialmente patogênicos isoladas foi submetida ao teste de Dean e teste de alça ligada em íleo de coelhos. Os vibrios potencialmente patogênicos encontrados em amostras de ostras foram V. alginolyticus (81 por cento ), V.parahaemolyticus (77 por cento ), V. cholerae não 0:1 (31 por cento ), V. fluvialis (27 por cento ), V. furnissii (19 por cento ), V. mimicus (12 por cento ) e V. vulnificus (12 por cento ) e em amostras de mexilhões foram V. alginolyticus(97 por cento ), V. parahaemolyticus(75 por cento ), V. fluvialis (47 por cento ), V. vulnificus (11 por cento ), V. cholerae não 0:1 (6 por cento ), V. furnissii (6 por cento ) e V. mimicus (6 por cento ). Observou-se acúmulo de fluido em alça ligada de íleo de coelho entre 0,25 e 0,49 ml/cm em 6,9 por cento das amostras, entre 0,5 e 0,99 ml/cm em 15,6 por cento e maior ou igual a 1 ml/cm em 15,1 por cento , e/ou intestino de camundongos lactentes (Teste de Dean) em 26,6 por cento das amostras testadas, confirmando o elevado potencial desses microrganismos em causar gastrenterite. Verificou-se ausência de variação sazonal e também, de correlação entre os vibrios potencialmente patogênicos isolados e os indicadores de contaminação fecal, confirmando que a presença desses microrganismos ocorre de forma autóctone e que, as condições climáticas foram favoráveis à sobrevivência dessas espécies em todas as épocas do ano. Considerando-se os resultados obtidos no presente estudo e o fato de que ostras e mexilhões são habitualmente ingeridos crus ou insuficientemente cozidos, pode-se concluir que sua ingestão constitui-se em um determinado grau de risco para a saúde do consumidor.In this work, 26 oysters samples (Crassostrea gigas), found in the market of São Paulo city and some coastal areas of São Paulo State, and 36 mussels samples (Perna perna), that were collected monthly in 3 coastal areas of Ubatuba city - SP., were analyzed for the potential patogenic vibrios occurrence. Samples were enriched in alcalin peptone water with (1 per cent ) and without sodium cloride and GSTB. Isolation was performed on TCBS agar. suspect sacharosis positive and negative colonies, resembling vibrio species, were presumptively identified on Kligler iron agar, and confirmed by complementary biochemical tests. Some of this potential patogenic vibrios were submitted to suckling mouse assay and rabbit ileal loop assay. Potential patogenic vibrios isolated from oyster samples were: V. alginolyticus (81 per cent ), V. parahaemolyticus (77 per cent ), V. cholerae non 0:1 (31 per cent ), V. fluvialis (27 per cent ) I V. furnissii (19 per cent ), V. mimicus (12 per cent ) and V. vulnificus (12 per cent ) and from mussels samples were: V. a.1ginolyticus (97 per cent ), V. parabaemolyticus (75 per cent ), V. fluvialis (47 per cent ), V. vulnificus (11 per cent ), V. cholerae non 0:1 (6 per cent ), V. furnissii (6 per cent ) and V. mimicus (6 per cent ). It was found 6,9 per cent of samples between 0,25 and 0,49 ml/cm of fluid accumulation in ileal loop assay, 15,6 per cent between 0,5 and 0,99 ml/cm and 15,1 per cent was equal or higher than 1 ml/cm. Among the samples assayed for suckling mouse 26,6 per cent were positive. These results confirm the high potential of these microrganisms to induce gastroenteritis. Seasonal variation as well as correlation between the potential patogenic vibrios isolated and the fecal contamination indicators were not found, confirming that the presence of such microrganisms occurs autochthonously and that the climate conditions were favourable to these species survival during the whole year. with the results of this work and considering that oyster and mussels are usually ingested raw or insufficiently cooked, the conclusion is that the ingestion of such mollusks presents a certain degree of risk for the consumer\'s health.
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Johnston, Olivia Ruth. "Distribution and biology of the marine invasive bivalve Theora lubrica (Semelidae)." Thesis, University of Canterbury. School of Biological Sciences, 2005. http://hdl.handle.net/10092/2453.
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This study examined aspects of the biology and distribution of the marine invasive bivalve Theora lubrica in the Lyttelton Basin from two distinct sampling areas. Samples were collected monthly, over a 13 month period (January 2004 and January 2005), with particular emphasis on seasonal sedimentary characteristics and contamination. The sample sites consisted of five Port sites and five Harbour sites. They were sampled using a 20 litre anchor dredge. In winter and summer, core samples from each of the sample sites were collected, and the top 1.5cm of sediment was used to obtain sediment characteristics. Sediment characteristics indicated a depositional setting, with an average grain size (diameter) of 8-10 μm, which did not vary seasonally. Analysis indicated that the sediments naturally flocculated, to the 100μm size range and were platykurtic. Organic content (OC) in the sediment in Lyttelton Port showed significant seasonal variation. OC was highest during the winter period corresponding to an increase of T. lubrica abundance. There were noticeable seasonal changes in the abundance of T. lubrica, with high winter and low summer population densities. The period for recruitment coincided with high T. lubrica densities, and the greater frequency of juveniles with shell length below 4.33 mm. Histological sections showed that spawning occurred during the summer, confirmed by the presence of high percentages of ovigerous females and mature males. Community analyses distinguished four distinct seasonal and spatial benthic populations. The populations exhibited greater total species richness during the summer (compared to the winter). T. lubrica, maintained high abundance during periods of low total species richness. Furthermore, there was evidence of a predator prey relationship between the crab Macrophthalmus hirtipes and T. lubrica. Trace metals and hydrocarbons showed seasonal and spatial variation between the Port and Harbour sediments. Only the arsenic, nickel and copper in the Port location were at concentrations likely to be toxic to the biota. No trace metals exceeded threshold limits in the Harbour. Levels of arsenic and nickel were highest in the summer and copper was at its highest concentration in the winter. However, there was little evidence to suggest that the sediment contamination affects T. lubrica or the rest of the benthic community directly. Thus, the significantly lower species richness at the Port location may be due to other influences (i.e. sediment disturbance from shipping). In conclusion T lubrica is regarded as an opportunistic marine invasive species which can inhabit areas not occupied by other marine macro-biota. T lubrica did not appear to negatively impact the other benthic species at the Lyttelton Port or Harbour sites. It provided a plentiful food source and increased species diversity in sediments that are frequently disturbed (by shipping and wave action). Furthermore, T lubrica may help reestablish native species to the Port area by filtering and processing contaminated sediments (bioturbation), potentially pioneering the way for greater species diversity in Lyttelton Port and Harbour.
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Amyot, Jean-Pierre. "Locomotion et répartition spatiale chez le bivalve d'eau douce Elliptio complanata." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ35561.pdf.
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Zhao, Liqiang [Verfasser]. "Deciphering the complexity of element incorporation into bivalve shells / Liqiang Zhao." Mainz : Universitätsbibliothek Mainz, 2017. http://d-nb.info/112833741X/34.
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Yan, Lina [Verfasser]. "Calibration study of bivalve shells : implications for paleoenvironmental reconstruction / Lina Yan." Mainz : Universitätsbibliothek Mainz, 2013. http://d-nb.info/1046091484/34.
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Somerset, Mark. "Effects of the s-triazines irgarol and atrazine on bivalve molluscs." Thesis, University of Portsmouth, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502738.
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Axiak, V. "Effects of pollution by petroleum hydrocarbons on the bivalve (Venus verrucosa)." Thesis, University of Westminster, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370918.
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Brooks, Jeremy David. "The aetiology of environmental stress responses and disease in bivalve molluscs." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259996.
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Thompson, Christine Mingione. "Species-specific patterns in bivalve larval supply to a coastal embayment." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62785.
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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2011.Cataloged from PDF version of thesis.
Includes bibliographical references.
Larval supply is an important process linking reproductive output to recruitment of benthic marine invertebrates. Few species-specific studies of bivalve larvae have been performed due to the lack of suitable methods for species identification. This thesis focused on applying a method to identify larvae from field samples from Waquoit Bay, MA using shell birefringence patterns. This method was then used to address variability in larval supply for three bivalve species on weekly, tidal, and hourly scales. Sampling weekly for six months during two years showed large variability in larval concentrations on this time scale. Abundances of most species were related to bay temperature, and species distributions among sampling sites were indicative of transport potential and population coherence. Greater growth of larvae in 2009 compared to 2007 was attributed to more wind-induced mixing and better food availability in 2009. Integrative samples over each tidal event for a 14-day period demonstrated that larvae were mostly constrained by water masses. During a period when there were sharp tidal signals in temperature and salinity, larval concentrations were higher in bay water compared to coastal waters on incoming tides. After a storm event, water mass properties were less distinct between tidal events and a semidiurnal signal in larval concentrations was no longer apparent. The timing of periods of high larval concentrations did not always coincide with periods of highest water mass flux reducing net export in some cases. On an hourly scale, the vertical distribution of larvae affected by water column stratification and strength of tidal flow. Strong currents and a fresh upper layer both prevented larvae from concentrating at the surface. There was little evidence of peaks in larval concentrations associated with a given tidal period. Species-specific data can provide new perspectives on larval transport. For the three species studied, Anomia simplex, Guekensia demissa, and Mercenaria mercenaria, different source areas, patterns for growth, and potential for export were observed. Applying species-specific identification methods to future studies of bivalve larval transport has the potential to relate larval abundance to settlement patterns, an important component of larval ecology and shellfish management.
by Christine Mingione Thompson.
Ph.D.
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Peñaloza, Navarro Carolina Soledad. "Characterization of genome-wide deviations from Mendelian inheritance in bivalve species." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33036.
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Marine bivalves are a group of species composed of clams, mussels and oysters. Bivalves are keystone species in coastal ecosystems and represent an increasingly important segment of the global aquaculture industry. Domestication of shellfish species is in the early stages, with few organized breeding programmes and a heavy reliance on wild seed. Consequently, the development and use of genomic markers may significantly assist shellfish aquaculture breeding and production. However, molecular genetic markers typically exhibit unusual patterns of segregation in bivalve species, which result in deviations from Mendelian expectations, and could potentially limit their use in parental assignment, mapping of quantitative trait loci and genomic prediction. Previous studies have suggested that segregation distortions originate at the larval stage, as a result of the linkage of markers to deleterious mutations. This high genetic load has been associated with the high fecundity of bivalve species. However, no direct evidence of a high incidence of de novo mutations has been provided. The aim of this thesis is to gain further insight into segregation distortions in bivalve species by studying the phenomenon at a genome-wide scale, using modern high-throughput sequencing technology. The studies presented in this thesis derive from experiments involving genotyping of parents and offspring from pair-crosses of three different bivalve species (the Pacific oyster Crassostrea gigas, the Blue mussel Mytilus edulis, and the GreenshellTM mussel Perna canaliculus) using high throughput sequencing and SNP arrays. The parent and offspring genotype data were used to characterize patterns of segregation distortion at a genome-wide level, followed by exploratory analyses to test hypotheses related to possible causes of this distortion. Three main findings resulted from the genome-wide analysis of segregation patterns. First, by using Restriction site Associated DNA sequencing (RAD-Seq) we observe that technical artefacts are more widespread than previously considered, contributing to apparent distortions via unreliable genotype calls. By analysing read depth data from RAD-Seq, we suggest that apparent homozygous genotype calls may actually be hemizygous, suggesting a very high frequency of null alleles which contribute to distorted segregation patterns. Bioinformatic pipelines to improve RAD-Seq locus assembly and marker genotyping for bivalve species are presented. Second, by using a high-density SNP array and RAD-Seq in pair crosses of Pacific oyster and aligning to the reference genome assembly, we find that segregation distortions cover extensive regions of the genome, and that certain genomic regions are consistently distorted in different families. Finally, following previous suggestions that the reproductive strategies of bivalve species may favour a high mutation rate, we provide preliminary evidence of a high incidence of de novo mutations that appear spontaneously (i) during male and female gamete formation and (ii) post-zygotically, during larval development. This putative high de novo mutation rate is likely to also contribute to deviations from Mendelian inheritance patterns in these species. New genomic technologies have allowed us to gain substantial insight into the intriguing yet poorly understood phenomena related to inheritance in bivalve species. The results have both fundamental and practical implications for genetic analysis interpretation and selective breeding for aquaculture in this large and highly diverse group of species.
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Denis, Françoise. "Génétique biochimique et moléculaire de la palourde Ruditapes Philippinarum (mollusque, bivalve)." Brest, 1995. http://www.theses.fr/1995BRES2032.
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Le developpement de nouvelles especes dans le milieu naturel souleve de nombreux problemes quand aux processus de mise en place des structures genetiques des populations. Le cas des palourdes indo-pacifiques ruditapes philippinarum est interessant en raison des possibilites de dispersion des alleles par l'intermediaire des larves planctoniques. L'etude de la genetique biochimique de cette espece est realisee sur trois populations du littoral atlantique breton situees dans deux zones geographiquement eloignees: le golfe du morbihan et la rade de brest. Du point de vue ecologique, deux de ces sites sont caracterises par une salinite variable, le troisieme par une salinite stable. Les phenomenes de selection, souvent observes dans les populations de mollusques bivalves, sont aussi rencontres chez cette espece. Le cadre de cette etude permet de mettre en evidence la sensibilite des palourdes a la salinite et confirme le role selectif de ce facteur abiotique sur la structuration des populations au niveau d'un locus: la leucine aminopeptidase-1 (lap-1). Les populations qui se developpent en milieu a salinite variable presente un taux d'heterozygotie plus eleve et une frequence de l'allele lap-1#9#5 plus faible. Les experimentations en milieu controle au laboratoire souligne la correlation existant entre l'heterozygotie et la tolerance aux chocs hyper-osmotiques. De plus, il revele la sensibilite de l'allele lap-1#9#5 a ce stress. L'analyse biochimique des genotypes rencontres a ce locus dans les populations naturelles indique la plus faible activite specifique de cet allele. Ce resultat est confirme par les mesures de coefficients de cinetique enzymatique. Ces observations eclairent les variations interpopulationnelles de frequences alleliques de la leucine aminopeptidase-1 et confirme l'influence de ce facteur environnemental sur la structure genetique des populations naturelles de r. Philippinarum. La deuxieme partie de l'etude genetique de la palourde indo-pacifique constitue une approche de la genetique moleculaire par la mise au point de techniques d'extraction et d'analyse de l'adn mitochondrial chez cette espece. A partir d'amorces heterologues, un fragment de l'adn mitochondrial a ete amplifie. Il a ensuite ete sequence afin de determiner la presence d'une phase ouverte de lecture potentielle dont seul une fraction a ete sequencee
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Lopes, Anabela Rodrigues. "Matriz orgânica solúvel do nacre da concha do bivalve Anodonta cygnea." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/6408.
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Mestrado em Biologia Aplicada - Biologia Molecular e CelularA biomineralização da concha dos moluscos é um processo controlado por uma matriz orgânica extracelular secretada para o espaço extrapaleal pelo epitélio calcificante. Já foram realizados alguns estudos dos quais se obtiveram algumas respostas sobre os constituintes da matriz. No entanto, quase todos tiveram como objeto de estudo moluscos das famílias Pteriidae e Pinnidae. Neste trabalho o animal estudado, o bivalve Anodonta cygnea, pertence à família Unionidae da qual se sabe muito pouco no que respeita à sua matriz orgânica. Das duas frações possíveis de obter pelo processo de extração apenas uma, a fração solúvel, foi analisada. A análise ocorreu a vários níveis nomeadamente ao nível da caracterização bioquímica por eletroforese, quantificação de matéria existente e localização da matriz diretamente na concha através da técnica de “immunogold”. Foram também produzidos anticorpos policlonais para a matriz e construída uma biblioteca de ADN complementar ao ARN mensageiro existente no epitélio calcificante sendo neste caso o folheto externo do manto. Da análise em eletroforese foram detetadas cinco frações proteicas de pesos moleculares de aproximadamente 106, 74, 59, 49 e 40KDa. A pequena quantidade de proteínas totais e de glicosaminoglicanos obtida da extração comprovou os demais estudos que referem que a percentagem de matriz orgânica existente na concha é baixa quando comparada com a componente inorgânica, neste caso constituída por carbonato de cálcio na forma de cristais de aragonite. Pela técnica de “immunogold” verificou-se que a matriz orgânica encontra-se essencialmente nos espaços intercristalinos mas existe também associada aos próprios cristais. Os resultados encontrados neste trabalho para esta espécie ao nível da caracterização bioquímica são semelhantes aos descritos no estudo de outra espécie da mesma família. Relativamente à localização da matriz orgânica na concha esta apresenta distribuição semelhante à da espécie Pinna nobilis embora pertençam a famílias diferentes. Apesar dos milhares de anos de evolução divergente, isto sugere que a matriz orgânica não deverá variar muito entre famílias na sua constituição e organização.
The biomineralization process of mollusc’s shell is controlled by an extracellular organic matrix which is produced by the calcifying epithelium and secreted into the extrapallial space. Some studies have already been performed and give some answers about organic matrix constituents. However almost all of them were on species of the families Pteriidae and Pinnidae. In the present work the study animal is the freshwater bivalve Anodonta cygnea, belonging to the Unionidae family, from which little is known about its organic matrix. From the extraction process it is possible to achieve two fractions of organic matrix, but only one, the soluble fraction, was the object of this study. Different techniques were used, including biochemical characterization by electrophoresis, quantification and detection of the matrix directly in the shell through the immunogold technique. Were also produced polyclonal antibodies against the organic matrix and a complementary DNA library, constructed with the messenger RNA of the outer mantle epithelium, which is in this animal the calcifying epithelium, used as a template. From the electrophoretic analysis five protein fractions were detected with molecular weights of approximately 106, 74, 59, 49 and 40 KDa. The small amount of the total protein and glycosaminoglycans obtained from the extraction indicate the low percentage of organic matrix when compared to the inorganic fraction which is in this case calcium carbonate in the form of aragonite crystals, situation confirmed in other studies. By the immunogold technique it was found that the organic matrix is mainly intercrystalline but it can also be found within the crystals. The results found in terms of biochemical characterization in this study with Anodonta cygnea are similar to those described for other members of this family. Regarding to the localization of the organic matrix in the shell, the results obtained are very similar to the localization founded in the Pinna nobilis although they belong to the different families. This suggests that the thousands of years of divergent evolution should not vary greatly between families in terms of constitution and organization of the organic matrix.
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Rolton, Anne. "Impacts of Karenia brevis on bivalve reproduction and early life history." Thesis, Brest, 2015. http://www.theses.fr/2015BRES0002/document.
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Karenia brevis, le dinoflagellé produisant des brevetoxines (PbTx), est la principale espèce d’efflorescences d’algues toxiques dans le Golfe du Mexique. Les effets de cette algue sur Mercenaria mercenaria et Crassostrea virginica sont méconnus tandis que les efflorescences coïncident avec la période de reproduction de ces espèces. Ce projet avait pour but de déterminer les effets i) d’une exposition à K. brevis en laboratoire et naturelle de terrain sur les processus physiologiques associés à la reproduction de M. mercenaria et C. virginica, et ii) d’une exposition à K.brevis sur la qualité et le développement des gamètes, embryons et larve de ces espèces. Suite à l'exposition des adultes de clams et d’huîtres à K. brevis, les paramètres physiologiques de la reproduction ont été affectés. La présence de PbTx dans les tissus des gamètes et le potentiel transfert maternel de PbTx à la progénie via les ovocytes, pourraient avoir entraîné les effets négatifs observés lors du développement larvaire.Les effets négatifs similaires causés par l'exposition des stades précoces à différentes préparations de cellules de K. brevis suggèrent que d'autres composés toxiques, en plus de PbTx, pourraient être impliqués dans la toxicité et, que la majorité des effets délétères se produisent durant les divisions embryonnaires.Le clam et l’huître américaine sont sensibles à K. brevis. Les effets négatifs sur les adultes et jeunes stades de vie, combinés à une exposition quasi-annuelle aux efflorescences de K. brevis, pourraient engendrer des perturbations majeures sur le recrutement des populations de ces espèces importantes, et avoir des répercussions environnementales et économiquesThe brevetoxin (PbTx) producing dinoflagellate, Karenia brevis is the most prevalent harmful algal bloom species in the Gulf of Mexico. The effects of this alga on Mercenaria mercenaria and Crassostrea virginica are poorly understood yet, blooms typically overlap with periods of reproduction and spawning in these species.The aims of this project were to determine the effects of i) laboratory and field exposure of K. brevis on the reproductive and related physiological processes of adult M. mercenaria and C. virginica and the quality of the offspring that were produced and ii) K. brevis exposure on gamete, embryo and larval development in these species.Following exposure of adult clams and oysters to K. brevis, negative effects were recorded on reproductive and physiological parameters. PbTx was recorded in gamete tissues, and maternal transfer of this PbTx to the offspring via the oocytes, may have resulted in the significant negative effects recorded on larval development up to the end of the lecithotrophic phase.The similar dose-dependent negative effects caused by direct exposure of gamete and early life stages to different cell preparations of K. brevis suggests that other toxic compounds in addition to PbTx may be involved in toxicity and, that the majority of negative effects occur during embryonic divisions.Hard clams and eastern oysters are susceptible to K. brevis exposure. The negative effects on adult and early life stages combined with the near- annual exposure to blooms of K. brevis could cause significant bottle-necks on the recruitment and population dynamics of these important species and, have wider reaching environmental and economic impacts
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SAGGESE, ILENIA. "Ecotoxicological profiles of metal engineered nanoparticles in mollusc bivalve Mytilus galloprovincialis." Doctoral thesis, Università del Piemonte Orientale, 2014. http://hdl.handle.net/11579/46561.
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Magalhães, Frederico Thomaisino 1981. "Mollusca Bivalvia da Baía do Almirantado, Ilha Rei George, Antártica : taxonomia e distribuição." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315908.
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Orientador: Flávio Dias PassosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O Brasil aderiu ao "Tratado Antártico" em 1975, e desde 1982 mantém o "Programa Antártico Brasileiro. A partir de 1984 as pesquisas brasileiras se concentraram na Baía do Almirantado, na Ilha Rei George, onde se localiza a base do país. A Baía do Almirantado foi eleita uma "Área Antártica Especialmente Gerenciada" pelas Partes Consultivas do Tratado Antártico e trata-se de um local representativo do ecossistema costeiro antártico, principalmente em termos de distribuição e composição de espécies. Lá os pesquisadores tem estudado a fauna bentônica da região, entre eles os Mollusca, que são abundantes e importantes no estudo dos processos que determinam a estrutura e o funcionamento das comunidades bentônicas marinhas. Este estudo se focou na classe Bivalvia, provendo um novo material de referência para identificação destes animais, e mais especificamente daqueles da Baía do Almirantado, apresentando-se como um guia ilustrado, com descrições detalhadas das conchas dessas espécies. Além disso, dados de distribuição geográfica e batimétrica foram reunidos para uma análise dessa fauna, na tentativa de qualificar a importância da região das Ilhas Shetland do Sul como um local estratégico para estudos em biogeografia. Foram identificadas 39 espécies de 18 famílias distintas, e seus dados de biologia, distribuição batimétrica e geográfica reunidos. As famílias mais representativas foram Philobryidae, Nuculanidae e Lasaeidae, contabilizando 15 espécies. As regiões com mais espécies em comum com a área estudada foram o Estreito de Magalhães, Ilha Georgia do Sul, Mar de Weddell, Península Antártica e sul do Chile; regiões notáveis pela riqueza de Bivalvia. As famílias mais largamente distribuídas, encontradas neste estudo, foram LImidae e Carditidae; e as mais restritas foram Siliculidae e Nuculanidae. A espécie com maior distribuição foi Cyclocardia astartoides, e as mais restritas Ennucula georgiana e Mysella narchii. As espécies encontradas se concentram nas profundidades até 1000 m, com seu número caindo para menos da metade além disso. Apenas seis espécies ocorrendo além dos 2000 m: Yoldiella profundorum, Limopsis marionensis, Limopsis lilliei, Adacnarca nitens, Limatula pygmaea e Cyclocardia astartoides. Este estudo demonstram a região da Baía do Almirantado como abrigo de uma fauna de Bivalvia composta por espécies estritamente antárticas, e outras que ocorrem ao norte da Convergência Antártica; sendo assim uma região importante para o estudo da distribuição destes animais
Abstract: Brazil abided to the "Antarctic Treaty" in 1975, and since 1982 maintains the "Brazilian Antarctic Program". As from 1984 the Brazilian researches focused on Admiralty Bay, in King George Island, where the country?s Antarctic base is located. Admiralty Bay was elected a "Antarctic Especially Managed Area" by the Antarctic Treaty Consultative Parties and is a representative place for the Antarctic coastal ecosystem, especially in views of species distribution and composition. In there researchers have been studying the regional benthic fauna, amidst it the Mollusca, abundant and important animals for the study of determinant process in the structure and operation of the marine benthic community. The present study focused on the class Bivalvia, providing a new reference source for identification of the group, and specifically for those of Admiralty Bay, presented as an illustrated guide with detailed shell descriptions for all the species found. Furthermore, data on geographic and bathymetric distribution were gathered for an analysis of this fauna, in attempt to qualify the importance of the South Shetland Islands as a strategic place for studies on biogeography. Thirty-nine species, of 18 distinct families, were identified, and their biological, geographical and bathymetrical data gathered. The most representative families were Philobryidae, Nuculanidae and Lasaeidae, counting 15 species in sum. The geographic regions with more species in common with the studied area were Strait of Magellan, South Georgia Island, Weddell Sea, Antarctic Peninsula and Southern Chile; notable regions for Bivalvia richness. The families found with the largest geographic distribution were Limidae and Carditidae, and the most restricted ones were Siliculidae and Nuculanidae. The species with largest geographical distribution was Cyclocardia astartoides, while the most restricted were Ennucula georgiana and Mysella narchii. The species found in this study are concentrated in depths until 1000 m, beyond that their number shortens to less than half. Only six occur deeper than 2000 m: Yoldiella profundorum, Limopsis marionensis, Limopsis lilliei, Adacnarca nitens, Limatula pygmaea and Cyclocardia astaroides. The present study shows Admiralty Bay as shelter to a Bivalvia fauna with strictly Antarctic species and northern ones, common north to the Antarctic Convergence, thus being an important place for studying the distribution of these animals
Mestrado
Ecologia
Mestre em Ecologia
46
Ludwig, Sandra. "Corbicula (Bivalvia, Corbiculidae) spp, na América do Sul : histórico de introdução, linhagens androgênicas e genética da invasão." reponame:Repositório Institucional da UFPR, 2015. http://hdl.handle.net/1884/48369.
Full textAbstract:
Orientador : Walter A. P. BoegerCo-orientador : Dr. Gustavo Darrigran
Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa: Curitiba, 29/05/2015
Inclui referências
Area de concentração: Zoologia
Resumo: O gênero Corbicula (Bivalvia, Corbiculidae) Megerle von Mühlfeld, 1811 possui linhagens sexuais e hermafroditas androgênicas que habitam ambientes estuarinos e de água-doce ao redor do mundo. As linhagens sexuadas de Corbicula estão restritas à região natural (Ásia, Austrália, Oriente Médio e África), enquanto que as linhagens invasoras são encontradas nos continentes Americano e Europeu. Dessa forma, acredita-se que reprodução androgênica pode ter um papel importante durante o processo de estabelecimento das linhagens invasoras em um novo ambiente. As linhagens androgênicas invasoras de Corbicula são entituladas como: Corbicula sp. forma A/R, Corbicula sp. forma C/S, Corbicula sp. forma B e Corbicula sp. forma Rlc, e quando estabelecidas em um novo ambiente, geram impactos ecológicos e econômicos significativos. Devido à alta variabilidade morfológica de suas conchas, a determinação específica das espécies de Corbicula utilizando somente dados morfológicos resulta frequentemente em uma determinação taxonômica errônea. Assim, esta tese de doutorado tem como objetivo: (i) identificar as linhagens Sul-Americanas de Corbicula utilizando dados de morfometria geométrica e dados moleculares do mtDNA citocromo oxidase subunidade I (COI) e de dez marcadores nucleares de microssatélites; (ii) inferir o relacionamento filogenético das linhagens invasoras de Corbicula da América do Sul com seus relativos da América do Norte e Europa, assim como, com as linhagens sexuadas da região natural; (iii) propor um método molecular para a detecção de larvas de Corbicula spp. em amostras de plâncton com o intuito de monitorar esses moluscos invasores e fornecer informações sobre o ciclo de vida e processo de dispersão no ambiente invadido. Baseando-se nos resultados obtidos, foi possível detectar duas linhagens invasoras de Corbicula na América do Sul, C. sp. forma A/R e C. sp. forma C/S. Além disso, espécimes com morfotipos e genótipos intermediários também foram detectados, que aqui foram considerados como consequência do mismatch citonuclear entre duas linhagens simpátricas de Corbicula. Os espécimes de Porto União, Santa Catarina, apresentaram ainda um haplótipo único (FWBra1) e que está presente unicamente nessa população. Ainda, foi detectada uma extensa variação morfológica nos espécimes da linhagem C. sp. forma A/R, mas que está restritamente associada à presença de um único genótipo e ao haplótipo mtDNA FW5; ou seja, apresentam um padrão genético clonal para a América do Sul. O mesmo padrão clonal se repetiu para a linhagem C. sp. forma C/S, cuja apresentou um único genótipo e a presença do único haplótipo mtDNA FW17. Adicionalmente, provavelmente, múltiplas introduções e admixture de novos propágulos de diferentes regiões invadidas podem estar propiciando a manutenção da diversidade clonal desses moluscos na América do Sul, caracterizando-se em uma metapopulação de clones entre os continentes Americano e Europeu, para cada uma das linhagens detectadas. Assim, o método de monitoramento molecular desenvolvido a partir do mtDNA COI se mostrou eficiente na detecção de larvas de Corbicula spp. invasoras, sendo possível detectar até mesmo uma única larva em 1000 mL de amostra de plâncton. Assim, o método molecular desenvolvido pode realizar o monitoramento/prospecção dos primeiros estágios larvais do ciclo de vida de Corbicula spp. em corpos d'água que foram invadidos e/ou que são considerados em risco de invasão eminente por esses moluscos.
Abstract: The genus Corbicula (Bivalvia, Corbiculidae) Megerle von Mühlfeld, 1811 has sexual and hermaphroditic androgenetic lineages which habitat estuarine and freshwater domains around the world. The sexual lineages of Corbicula are restricted to natural range (Asia, Australia, Middle East and Africa), while the invasive lineages are found in American and European continent and, are characterized by hermaphroditic androgenetic reproduction. In this way, it is believed that the androgenetic reproduction can play an important role during the stablishment process of invasive lineages into new environment. The invasive androgenetic lineages of Corbicula are known as: Corbicula sp. form A/R, Corbicula sp. form C/S, Corbicula sp. form B and Corbicula sp. form Rlc and, when stablished into new environment they cause significative ecological and economic impacts. Besides that, they present high morphological variability in their shells, thus, the specific determination of species of Corbicula using only morphological data often results in erroneous taxonomic determination. For those reasons, this doctoral thesis aims to: (i) identify the South American lineages of Corbicula using morphometric geometric data and molecular data from mtDNA cytochrome oxidase subunit I (COI) and ten nuclear markers of microsatellites; (ii) infer the phylogenetic relationships of invasive lineages of Corbicula of South America with their counterparts of North America and Europe, as, sexual lineages from natural range and; (iii) propose a molecular method to larvae detection of Corbicula spp. in plankton samples, in order to monitoring these invasive molluscs and provide information about their life cycle and dispersion process into invaded environment. Based on obtained results of this thesis, we detected two invasive lineages of Corbicula in South America: C. sp. form A/R e C. sp. form C/S. Besides that, specimens with intermediate morphotype and genotype were also detected, which were considered as consequence of cytonuclear mismatch between sympatric invasive lineages of Corbicula. Specimens of Porto União, Santa Catarina state, presented intermediate genotype but unique mtDNA COI haplotype (FWBra1) and, until now, it is presented only in this population. Also, it was detected an extensive morphological variation in C. sp. form A/R specimens but it is restricted associated to the presence solely of one genotype and one mtDNA COI haplotype FW5; in other words, those specimens presented a clonal genetic pattern to South America. The same clonal pattern repeated to C. sp. form C/S, which presented solely one genotype and one mtDNA COI haplotype FW17. Additionally, most probably, multiple introductions and admixture of new propagules from distinct invaded regions are propitiating the maintenance of clonal diversity of these molluscs into South America, characterizing themselves in metapopulation of clones between American and European continents, to both lineages detected. Finally, the molecular method developed through mtDNA COI was efficient in detection of larvae of invasive Corbicula spp., which could detect even one larva in 1000 mL of plankton sample. In this way, the molecular method developed can monitoring and prospects the early stages of larvae of Corbicula spp.' life cycle in invaded watersheds and/or those that are considered in risk to eminent invasion by these molluscs.
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Guimarães, Alaíse Gil. "Contaminação do molusco Anomalocardia brasiliana (Gmelin, 1791), por Vibrio parahaemolyticus e Vibrio vulnificus, na Região Norte da Baia de Todos os Santos - Bahia." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255544.
Full textAbstract:
Orientador: Arnaldo Yoshiteru KuayeTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A costa do litoral baiano é considerada uma das mais férteis da costa brasileira, levando-se em consideração a extensa faixa de litoral, pois ela é capaz de gerar a maior proliferação de vida marinha com uma grande quantidade de peixes, crustáceos e moluscos. Por essa razão, a população costeira tem sua subsistência alimentar e econômica vinculada ao extrativismo de frutos do mar, destacando-se entre eles o molusco bivalve comestível Anoma/ocardia brasiliana (Gmelin 1791), popularmente conhecido na região como "chumbinho",que é extremamente apreciado pela culinária baiana. Com o objetivo de pesquisar a ocorrência de Vibrio parahaemo/yticus e Vibrio vu/nificus, 31 amostras de A. brasiliana, de água do mar e de sedimento foram coletados de abril de 2000 a março de 2001, nas praias do município de Salinas da Margarida, região norte da Baía de Todos os Santos-BA. As amostras foram avaliadas quanto ao Número Mais Provável (NMP) de V. parahaemolyticus e V.vulnificus sendo as colonias sugestivas identificadas presuntivamente em meio de Tríplice Açúcar e Ferro (TSI), e a confirmação realizada através dos testes bioquímicos complementares. O Número Mais Provável (NMP/g) de V. parahaemolyticus nas amostras de "chumbinho", sedimento e água do mar variou de <3 a 1,1x103, <3 a 93 e <0,3 a 4,3 respectivamente. O Número Mais Provável de V.vulnificus para as amostras de "chumbinho", foram de <3 a 3 e de <0,3 a 0,4 para a água do mar e abaixo do limite de detecção do método para as amostras de sedimento. A freqüência de amostras de "chumbinho", sedimento e água do mar positivas para V. parahaemoliticus foi de 64,5%, 77,4% e 64,5%, respectivamente, enquanto que para o V.vulnificus foi de 3,2% para "chumbinho" e de 6,4% para a água do mar. Não se observou correlação entre as variáveis do ambiente (salinidade, temperatura e pH), com o isolamento dos microrganismos estudados constatou-se a ausência da influência da sazonalidade sobre a freqüência de V. parahaemolyticus. Todas as cepas de V. parahaemolyticus isoladas submetidas ao teste de Kanagawa apresentaram resultados negativos. A utilização de vinagre e de suco de limão mostrou-se eficiente na redução do número inicial de V. parahaemolyticus em A. brasiliana artificialmente contaminado. Em virtude da cidade de Salinas da Margarida ser uma das maiores fornecedoras de "chumbinho" e conhecendo a maneira com que os mesmos são comercializados, é importante e necessária a implantação de Boas Práticas de Produção, tendo como objetivo a qualidade desse molusco e a garantia da saúde dos consumidores.
Abstract: The Bahia State - Brazil coastline is considered one of the most fertile of the Brazilian coast, taking consideration the extensive seaboard, therefore it is capable to generate the most proliferation of sea life with a great amount of fishes, crustaceans and clams. For this the coastal population has its alimentary and economic subsistence associated to the extractives of seafood. Among the mussels the Anomalocardia brasiliana (Gmelin, 1791) is popularly known as "chumbinho", can be detected between the bivalve mollusks and is particularly appreciated by the bahian cuisine to investigate the occurrence of Vibrio parahaemolyticus and Vibrio vulnificus, thirty one samples of the Anomalocardia brasiliana, seawater and sediment were collected trom April of 2000 to March of 2001, in the beaches of the city of Salinas da Margarida, north region of the Baía de Todos os Santos - Bahia. The Most Probable Number (MPN) were used to quantify V. parahaemolyticus and V. vulnificus in samples and the suggestive colonies were presumptively identified in Triple Sugar and Iron Medium (TSI), and the confirmation was carried through the biochemical tests. The determination of the Most Probable Number (/g or Iml) of V. parahaemolyticus varied from <3 to 1,1 X 103 for "chumbinho", <3 to 93 for sediment and between <0,3 to 4,3 for seawater samples, while the MPN (/g or ml) of V. vulnificus were between <3 to 3 for "chumbinho" and <0,3 to 0,4 for seawater; in the sediment samples this bacteria wasn't quantified. The frequency of V. parahaemolyticus in "chumbinho", sediment and seawater was 64,5%, 77,4% and 64,5% respectively, while for V.vulnificus it was 3,2% in "chumbinho" and 6,4% in seawater. Statistically were not found correlations between the environmental variable (salinity, temperature and pH) and the presence of the microorganisms, as well as the seasonal variation. The efficiency of vinegar and lemon juice in the reduetion of V. parahaemolyticus in artificially contaminated was shown. Due to the fact that the town of Salinas da Margarida be one of the major provider of "chumbinho" and knowing the way that they are commercialized , it is important and necessary the implementation of good manufacture practices, aiming the quality of the mollusks and guarantee of the consumers health.
Doutorado
Doutor em Tecnologia de Alimentos
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Quast, Mônica Paiva 1977. "Moluscos bivalves (Arcoida e Ostreoida) da costa Sudeste do Brasil." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315781.
Full textAbstract:
Orientador: Antonia Cecilia Zacagnini AmaralDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Os moluscos bivalves das ordens Arcoida e Ostreoida (Bivalvia) procedentes do Programa BIOTA / FAPESP - Bentos Marinho e do Programa REVIZEE / Bentos - Score Sul são o objeto de estudo do presente trabalho. O objetivo principal foi ampliar o conhecimento sobre as espécies destes grupos, fornecendo descrições e ilustrações do material examinado, bem como dados sobre as distribuições geográfica e batimétrica. As coletas foram realizadas ao largo do Estado de São Paulo em substrato não-consolidado desde a região entremarés até cerca de 800 m de profundidade. Nas praias arenosas, foram utilizados amostradores cilíndricos, enterrados até 20 cm de profundidade, e, no infralitoral, pegadores van Veen e "Box -corer", draga e rede. O material foi identificado com o auxílio de microscópio estereoscópico, de microscópio eletrônico de varredura e de literatura especializada, e fotografado com câmera digital. No total, 1060 indivíduos foram examinados, sendo reconhecidas 21 espécies pertencentes a oito famílias: Arcidae (5 espécies), Limopsidae (3), Philobryidae (1) e Glycymerididae (2) (Arcoida); Ostreidae (1), Pectinidae (4), Propeamussiidae (4) e Anomiidae (1) (Ostreoida). Foram registradas duas ocorrências novas para a costa brasileira, Bathyarca pectunculoides e Cyclopecten subimbrifer. As descrições de algumas espécies foram ampliadas. Uma análise de agrupamento com base na similaridade faunística permitiu definir grupos de estações de acordo com a profundidade, estabelecendo faixas batimétricas caracterizadas por determinados grupos de espécies
Abstract: Bivalve mollusks (orders Arcoida and Ostreoida) collected during the BIOTA / FAPESP-Bentos Marinho Program and part of the REVIZEE / Bentos - Score Sul Program were analyzed in order to improve the knowledge about these taxa in Brazilian coast. The material was collected in soft bottoms in state of São Paulo from the intertidal zone to about 800 m depth, with cylindrical corers on beaches and van Veen, Box-corer dredge and trawl in the sublittoral zone. Bivalves were identified and photographed using a stereoscope microscope and a digital camera. A total of 1060 individuals were examined and 21 species recognized belonging to eight families: Arcidae (5 species), Limopsidae (3), Philobryidae (1) e Glycymerididae (2) (Arcoida); Ostreidae (1), Pectinidae (4), Propeamussiidae (4) e Anomiidae (1) (Ostreoida). There are two new occurrences for Brazilian coast, Bathyarca pectunculoides and Cyclopecten subimbrifer. Descriptions of some species were improved. A cluster analysis determined site groups related to depth
Mestrado
Mestre em Ecologia
49
Ferreira, Liana Pinho. "Diagnóstico e infecção experimental por Perkinsus beihaiensis em anomalocardia brasiliana (MOLLUSCA:BIVALVIA) no Estado do Ceará." reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/16311.
Full textAbstract:
FERREIRA, L. P. Diagnóstico e infecção experimental por Perkinsus beihaiensis em anomalocardia brasiliana (MOLLUSCA:BIVALVIA) no Estado do Ceará.. 2013. 61 f. Dissertação (Mestrado em Ciências Marinhas Tropicais) - Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, 2013 .Submitted by Geovane Uchoa (geovane@ufc.br) on 2016-04-07T14:38:54Z No. of bitstreams: 1 2013_dis_lpferreira.pdf: 1374005 bytes, checksum: 80f9e7531dfa6f2d25a1fb94f33ff1a2 (MD5)
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Perkinsiosis is a disease caused by protozoa of the genus Perkinsus and causes massive mortality in several species of commercial bivalve mollusks, mainly in Europe and United States. Thus, the present study aimed to verify the occurrence of Perkinsus in the cockle Anomalocardia brasiliana (Veneridae) from a natural population and evaluate the impact of an experimental challenge with Perkinsus beihaiensis in this host. Specimens of A. brasiliana were collected in the Timonha River estuary (West coast of Ceará) in March 2012 (n= 150) and submitted to the diagnosis of Perkinsus spp. by tissues incubation of gills and rectum in Ray’s Fluid Thioglicollate Medium (RFTM). The confirmation of the genus Perkinsus was done by PCR analyzes (ITS) and subsequent sequencing. The RFTM showed the presence of hypnospores of Perkinsus infecting the tissues of the animals, with a prevalence of 14.7% (22/150) and intensity of infection ranging from very mild (n= 18) to mild (n= 4). Analyzes of PCR and sequencing confirmed that this species is Perkinsus beiahiensis. So this is the first record of this species in A. brasiliana. In order to assess the impact of an experimental challenge with P. beiahiensis in cockles from the Jaguaribe River estuary (east coast of Ceará), animals (n= 6) were distributed in 12 tanks (6 controls and 6 treatments). A cell suspension of hypnospores of P. beihaiensis was prepared from tissues of Crassostrea rhizophorae naturally infected. The tissues were incubated in RFTM to obtain a suspension of hypnospores. The animals of the treatment group were challenged by injection of 100μl of cell suspension of the parasite (125 cells) into the paleal cavity and the control animals received 100μl of sterile filtered seawater (AMFE). The challenge lasted 30 days and samples of cockles were collected in the 15th (n= 25) and 30th (n= 41) day after injection for pathological analyzes (RFTM, histology and PCR). The mortality of the animals was recorded daily. Mortalities occurred only during the first 15 days of the experiment (n = 6, of the treatment group), but it was not detected Perkinsus sp. in these animals. From the animals collected in the 15th day, 8 of 17 (control group, 47%) and 2 of 14 (treatment group, 14.3%) had hypnospores of Perkinsus sp. (RFTM) with intensities of infection ranging from very mild to mild, greater in the treatment group than in the control group. From the animals collected in the 30th day, 4 of 19 (control group, 21%) and 4 of 22 (treatment group, 18.2%) were diagnosed as infected with Perkinsus sp., with intensities of infection ranging from very mild to mild, higher in the treatment group than in the control group. The histopathological analyzes confirmed the presence of cells of Perkinsus sp. infecting the organs of the cockles in the two groups, but the treatment group was the only one with cells being phagocytosed The proliferating cells of Perkinsus sp. occurred in both groups. PCR analyzes confirmed the presence of Perkinsus sp. in 4 of 6 animals analyzed (66.7%). This work revealed that the cockle A. brasiliana already is a natural host of Perkinsus beihaiensis, and a challenge with cells isolated from P. beihaiensis causes induction to infection, but the host recovers itself quickly and efficiently activating defense mechanisms.
A perkinsiose é causada por protozoários do gênero Perkinsus e causa mortalidades massivas em diversos moluscos bivalves comerciais, principalmente na Europa e nos Estados Unidos. O presente trabalho teve como primeiro objetivo verificar a ocorrência de Perkinsus em Anomalocardia brasiliana (Veneridae) de uma população natural do Rio Timonha, litral oeste do Ceará. Os espécimes (n=150) foram coletados em março de 2012 e submetidos ao diagnóstico de Perkinsus spp. por incubação de tecidos das brânquias e do reto em meio líquido de tioglicolato de Ray (RFTM). A confirmação do gênero foi feita por análises de PCR (ITS) e posterior sequenciamento. A RFTM mostrou a presença de hipnósporos de Perkinsus infectando os tecidos de A. brasiliana, com uma prevalência de 14,7% e com intensidades de infecção variando de Muito Leve (n = 18) a Leve (n = 4). As análises da PCR e do sequenciamento confirmaram tratar-se de Perkinsus beiahiensis. Este é o primeiro registro desta espécie em A. brasiliana. O segundo objetivo do estudo foi avaliar o impacto de um desafio experimental com P. beiahiensis neste hospedeiro. Para tal, foram coletados 72 exemplares no Estuário do Rio Jaguaribe (litoral leste do Ceará), que foram distribuídos em 12 tanques (6 controles e 6 tratamentos). Uma suspensão celular de hipnóporos de P. beihaiensis foi preparada a partir de tecidos de ostras Crassostrea rhizophorae naturalmente infectadas, a partir de incubação em RFTM. Os animais do grupo tratamento foram desafiados por injeção na cavidade palial de 100 μl da suspensão celular do parasita (125 células) e os animais controle receberam 100 μl de água do mar filtrada estéril (AMFE). O desafio durou 30 dias e amostras de búzios foram coletadas no 15º (n = 25) e 30º (n = 41) dias após injeção, para análises patológicas (RFTM, histologia e PCR). Mortalidades ocorreram somente em 16,7% dos animais do tratamento, mas não foi detectado Perkinsus sp. nestes animais. Dos animais coletados para RFTM no 15º dia, 47% do controle e 14,3% do tratamento apresentaram hipnósporos de Perkinsus sp., com intensidades de infecção variando de muito leve a leve. Dos animais coletados no 30° dia, 21% do controle e 18,2% do tratamento estavam infectados por Perkinsus sp., com intensidades de infecção variando de muito leve a leve. As análises histopatológicas confirmaram a presença de Perkinsus sp. infectando os órgãos de A. brasiliana nos dois grupos, no entanto somente o grupo tratamento apresentou células sendo fagocitados, ao passo que células em proliferação de Perkinsus sp. ocorreram nos dois grupos. As análises de PCR confirmaram a presença de Perkinsus sp. em 66,7% dos animais analisados (n = 6). Este estudo é o primeiro registro de P. beiahiensis em A. brasiliana. A etapa experimental evidenciou que este já é um hospedeiro natural deste patógeno e que um desafio com celulas isoladas de P. beihaiensis induz a infecção, no entanto o hospedeiro se recupera de forma rápida e eficiente mediante a ativação de mecanismos de defesa.
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Aranha, Tiago Porto. "Situação atual da ocorrencia do bivalve invasor Isognomon bicolor no litoral norte paulista e variabilidade genetica da especie no sudeste brasileiro." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316373.
Full textAbstract:
Orientadores: Luiz Francisco Lembo Duarte, Vera Nisaka SolferiniDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A quantidade de espécies envolvidas, a amplitude geográfica e a freqüência de ocorrência das invasões biológicas não conhecem precedentes. Atualmente as invasões são consideradas um processo composto de múltiplos estágios, dinâmico no espaço e no tempo. As populações invasoras podem estacionar em determinados estágios e até regredir a estágios anteriores antes de atingir a fase de clímax. As invasões são consideradas uma das grandes causas da extinção de espécies no planeta, desta forma, a compreensão dos mecanismos e fatores que influenciam o sucesso das invasões e o entendimento de seus efeitos em comunidades nativas é fundamental. O objeto de estudo do presente trabalho é o bivalve invasor Isognomon bicolor em costões rochosos do sudeste do Brasil. No capítulo I, padrões de distribuição e dominância de populações localizadas no litoral norte de São Paulo foram documentados. A situação atual da invasão de I. bicolor foi avaliada frente às populações de organismos nativos da área. No capítulo II, padrões de variabilidade e estruturação genética de populações de I. bicolor no litoral sudeste foram descritos e comparados com aqueles para populações do bivalve nativo Brachidontes solisianus. A combinação dessas duas abordagens permitiu uma maior compreensão do processo de invasão de I. bicolor e das conseqüências dessa invasão sobre as espécies nativas. Atualmente I. bicolor apresenta-se amplamente distribuído no litoral norte de São Paulo, entretanto, ao contrário de estudos anteriores, suas populações apresentam baixas porcentagens de cobertura nos costões onde ocorre. Tal fato deve-se a um evento de mortaliade em massa pelo qual a espécie passou recentemente. A alta variabilidade e baixa estruturação genética observada, semelhante à encontrada para o bivalve nativo B. solisianus, são indícios de um processo de invasão costituido por múltiplos episódios de introdução e da grande capacidade de dispersão do invasor. Esses resultados são preocupantes pois sugerem que as populações de I. bicolor estão relativamente estáveis e conectadas entre si, tornando sua exitinção na costa sudeste do Brasil improvável, mesmo após a ocorrência do evento de mortalidade em massa
Abstract: The species number, geographic scale and frequency of biological invasions are unparalleled. Currently, invasions are considered as a several stages process, dynamic in space and time. The invasive populations can remain at some stage or return to earlier stages before reaching the invasion climax. Invasions are considered one of the major causes of species extinction on the planet and thus. Understanding mechanisms and factors that influence invasion success and its effects on native communities is of primary imporatance. The present work studied the invasive Isognomon bicolor populations along the southeastern coast of Brazil. In Chapter I, the distribution and the dominance patterns of I. bicolor were documented along the northern coast of São Paulo. The population attributes of the invasive species I. bicolor were evaluated and compared to the population attributes of native organisms in the sampled area. In Chapter II, the genetic variability and the structure patterns of four I. bicolor populations on southeastern Brazilian Coast were analyzed and compared with those of the native Brachidontes solisianus populations. The combination of these two approaches has enabled a better understanding of I. bicolor invasion process and its consequences for native species. Currently, I. bicolor has become widely distributed in the northern coast of São Paulo, however, unlike previous studies, I.bicolor is not dominant in the rocky shores. This fact may be caused by a recent mass mortality event. The high variability and low genetic structure observed, similar to the genetic attibutes of the native bivalve B. solisianus populations, are evidences of an invasion process with multiple introduction events and of the large invader dispersal ability. These results are concerning as they suggest that I.bicolor populations are relatively stable and connected to each other, making its extinction in the southeastern coast of Brazil unlikely, even after the occurrence of a mass mortality event
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Ecologia
Mestre em Ecologia