O atual conhecimento sobre a margem do manto em moluscos bivalves é extenso, incluindo informações sobre morfologia, função e diversidade. Bivalves da família Pectinidae, também conhecidos como vieiras, possuem complexa margem palial, organizada em três pregas, incluindo olhos e tentáculos. Questões acerca do desenvolvimento da margem do manto em bivalves continuam amplamente incompreendidas, assim como a relação entre características paliais ao longo dos diferentes estádios do ciclo de vida. Neste contexto, a presente investigação utilizou a espécie de vieira Nodipecten nodosus como modelo para compreensão da morfogênese da margem palial em Pectinidae, com ênfase na origem e diferenciação das pregas paliais e estruturas associadas. Para contemplar esses objetivos, espécimes em diferentes estádios de desenvolvimento larval e pós-metamórfico foram analisados por meio de técnicas integradas de microscopia (i.e., histologia, microscopia eletrônica de varredura e transmissão, e imunocitoquímica aplicada à microscopia confocal). Inicialmente, a margem palial em larvas véliger de N. nodosus não é pregueada, porém, ao longo do desenvolvimento, dois processos de evaginação são determinantes na formação das pregas paliais. O primeiro ocorre no estádio de pedivéliger, originando as pregas externa e interna, bem como o sulco do perióstraco. O segundo ocorre após a metamorfose, sendo responsável pela origem da prega palial mediana a partir da porção interna da prega interna. Os sistemas muscular e nervoso da margem palial têm origem durante o período larval, tornando-se amplamente desenvolvidos posteriormente. Estruturas associadas, como tentáculos e olhos paliais, são formadas apenas após a metamorfose, e compõem a complexa condição final da margem do manto em Pectinidae. Os diferentes tipos tentaculares possuem desenvolvimento e anatomia similar, entretanto diferem quanto ao tamanho, tipo de musculatura, organização ciliar e presença de células glandulares. Os olhos paliais em formação diferenciam-se gradualmente em sentido proximal-distal, essas características morfológicas sugerindo um nível simples de fotopercepção direcional como condição inicial. Os dados aqui apresentados para N. nodosus permitiram propor um modelo geral para o desenvolvimento da margem palial em Pectinidae, além de contribuir para o entendimento da morfogênese dessa região em Bivalvia / Current knowledge of the bivalve mantle margin is extensive, covering several aspects of its morphology, function and diversity. Bivalves from the family Pectinidae, also known as scallops, bear three pallial folds at the mantle margin, including complex structures, such as tentacles and eyes. The development of the bivalve mantle margin is still poorly understood, the morphogenesis and functional anatomy of mantle margin features during developmental stages being enigmatic. The present investigation used the scallop Nodipecten nodosus (L. 1758) as a model species to understand mantle margin morphogenesis in the Pectinidae, with emphasis on the origin and differentiation of pallial folds and associated pallial structures. To achieve these goals, specimens from larval and postmetamorphic stages were thoroughly analyzed by means of integrative microscopy techniques (i.e., histology, scanning and transmission electron microcopy, and immunocytochemistry combined with confocal microscopy). In veliger larvae of N. nodosus, the mantle margin is initially unfolded, two folding processes being crucial for pallial fold establishment during further development. The first one occurs by the pediveliger stage, forming the outer and inner folds, as well as the periostracal groove. The second folding process takes place after metamorphosis and is responsible for the formation of the middle pallial fold from the inner region of the inner mantle fold. The emergence of muscular and nervous systems in the mantle margin occurs early during development, at the larval stage. Associated pallial structures, including tentacles and eyes, develop only after metamorphosis, and contribute to the complex final condition of the mantle margin in Pectinidae. Although different tentacular types have similar development and anatomy, they differ in size, muscle type, ciliary organization, and gland cells distribution. Developing pallial eyes exhibit gradual differentiation in a proximal-distal direction, and their morphological features suggest a simple level of directional photoreception as the initial ocular condition in juveniles. The present investigation conducted with N. nodosus provided a general model to understand mantle margin development in the Pectinidae, as well as insights into the morphogenesis of this region in the Bivalvia

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective. These hypotheses were tested using data from shell size measurements and morphology primarily from molluscs and brachiopods from both North America and Denmark.. Morphological differences were evaluated using Elliptical Fourier Analysis (EFA) of outline shape in conjunction with Principle Components and Canonical Variate Analysis. The first part of this study provides a detailed methodology for data collection and analysis. New methods were developed which display promise in improving the degree to which differences and similarities in shape can be elucidated using EFA. These methods were then employed to test hypotheses of morphological change through minor events of local significance in the Florida Neogene and following the K/Pg mass extinction. Data sources for the K/Pg mass extinction were from high resolution (10 cm intervals) collection of bulk samples from the Brazos River in Texas as well as reposited museum specimens for the Braggs locality in Alabama and Danish samples. Study of size and evolution through more minor local events in the fossil record entailed measurements and shape analysis of left valves of bivalves from the genus Chine. Various environmental changes occurred at variousmpoints during the Neogene in Florida Neogene, most profoundly documented during the Plio-Pleistocene with accompanying faunal turnover. TheChione specimens analyzed were derived from a discontinuous sequence encompassing ~18 Ma and represent material from the Miocene Chipola Formation through to the Recent. The size of Chione increased from the Miocene to the Pliocene and then decreased from the Pliocene into the Pleistocene possibly due to lower primary productivity. The later part of the Pleistocene into the Recent was characterized by increased size relative to the early Pleistocene and size was stable through this interval. Morphologically, Chione changed in shape from the Miocene to the Pliocene, but remained in stasis from the Pliocene to the Recent suggesting that stabilizing selection may work well during periods of rapid, minor, environmental perturbations. There were a number of global changes occurring within the late Maastrichtian pr and the results of size measurements of molluscs demonstrate a decrease in size prior to the K/Pg mass extinction in Texas likely in response to a number of global scale events occurring towards the close of the Cretaceous that was also associated with morphological evolution in the small bivalve Breviarca webbervillensis. Paleocene material from Texas was dominated by smaller, newly evolved allochthonous grazing gastropods. These gastropods are thought to be newly evolved lineages as their first occurrence is marked in the Paleocene. Smaller sized nuculid bivalves were also a prominent feature in the Texas Paleocene and showed a rapid size beginning 40 cm above the boundary clay. At Braggs, Alabama, two groups, gastropods and oysters showed decreases in size across the boundary, and these changes are most likely a product of animpoverished Paleocene ecosystem. The pectinids were the only group of bivalve mollusc to xii reduce in size following extinction in Denmark most likely in response to a reduction in bryozoan substrate which resulted in a very soft coccolith-derived mud substrate in the mass extinction's aftermath. Size measurements from the Danish brachiopods showed reductions in size across the boundary in all genera except Rugia. There was a marked size reduction in specimens from the upper Maastrichtian at Stevns Klint as compared to the lower Maastrichtian at Mons Klint. The reasons for this are most likely due to lower temperatures at Stevns based on isotope data as well as lower productivity evidenced by lower δ13C values. There was a change in morphology for Terebratulina chrysalis in the earliest Paleogene due to shifted selective pressures favoring increased surface area as an adaptation to softer substrates. Size reduction within Danish sequences is evolutionary in nature as the Danian is characterized by different species within existing Maastrichtian genera and two new genera. The results of this study demonstrate that changes in body size can be a result of evolution from changing selective pressures as well as ecological perturbations. Distinguishing evolutionary forcings from ecological requires the collection and understanding of morphological data. Changes in size for Terebratulina chrysalis could have easily been interpreted as ecological were it not for morphological results showing the changes in surface area resulting from changing selective pressure. Late Cretaceous changes in climate and sea level produced observable changes in size and morphology in Breviarca webbervillensis. Potential size selectivity of the K/Pg mass extinction failed to account for any of the patterns observed in the data. Gryphaeid oysters in Denmark would have been a perfect candidate to support conclusions of size selectivity as they were the largest molluscs measured in this study and survived mass extinction.

This diploma thesis deals with malacological research of selected forest localities in the natural park Džbán (Central Bohemia). The goal of this work is to molluscan explore composition in target area and compare results with the research of Dr. Vojen Ložek from years 1947-2010. His collections, which are deposited in the Repository of the National Museum in Prague - Horní Počernice, were processed in detail for this purpose. Obtained results enabled evaluation of changes in researched localities and the impact of such changes on composition of malacocenoses over the years. Standard malacological research was performed in selected localities of Džbán area. At 20 forest stations, we applied the method of soil samples, at 1 wetland locality we applied a method of wet washout. Collected material was further processed, determined and assessed. Altogether, 65 species of mollusc were found in selected area. Place called Cikánský dolík was chosen for the didactic part of this diploma thesis, which means a proposal for field trip of natural science. Such provided instruction is suitable for pupils from the 2nd level of basic schools. After adjustment, it can be used for younger pupils or older students. A guide containing 25 species of terrestrial snails of Džbán area was created as an aid. This guide...

Les infections d'origine alimentaire constituent un problème de santé publique majeur et présentent un impact économique important. Les agents pathogènes incriminés peuvent être d'origine bactérienne, virale ou parasitaire. Les conséquences de ces infections sur la santé des consommateurs peuvent être majeures, en fonction du statut immunitaire de chaque individu et de la provenance de l'agent infectieux, la mondialisation ayant accru les risques de dissémination de pathogènes viables virulents. Les denrées à risque sont principalement les aliments frais consommés crus ou peu cuits. Ceux-ci sont irrigués en continu durant leur croissance par des eaux pouvant être potentiellement contaminées par des agents infectieux.Au cours de ce travail, nous avons développé une stratégie d'extraction et de détection des parasites Toxoplasma gondii, Cryptosporidium et Giardia à partir de basilic et de framboise. Nous avons pour cela développé une technique d'immuno-capture des oocystes de Toxoplasma gondii grâce à un anticorps monoclonal dirigé contre la paroi des oocystes ainsi que des techniques de détection des trois parasites par qPCR. Ces protocoles ont été validés par des essais inter-laboratoires avec la participation de quatre laboratoires partenaires de ce projet. Nous avons par la suite cherché à mieux appréhender les risques réels pour les consommateurs en réalisant une étude mettant en parallèle une Reverse transcriptase PCR avec des essais in vivo, permettant ainsi de mettre en corrélation la viabilité des parasites avec leur infectiosité.Ce travail contribue à mieux maitriser les risques sanitaires liés à la présence de parasites dans lesdenrées alimentaires , par le biais d'une stratégiesusceptible d'être proposée aux industriels et normalisée. / Foodborne infections are a major public health problem and have a significant economic impact. Pathogens implicated in these outbreaks can be bacteria, viruses and parasites. Their impact on the consumer's health can be significant, depending on the immune status of the person and the pathogen source. Globalization has increased the risk of spreading of viable and virulent . The food at risk is mainly fresh food, eaten raw or undercooked, which has been widely irrigated by potentially contaminated waters during production. In this study, we have developed methods to extract and detect Toxoplasma gondii, Cryptosporidium and Giardia parasites from basil and raspberry with techniques able to detect the three parasites by qPCR. In this aim, we have developed a technique for the immuno-capture of Toxoplasma gondii oocysts using a monoclonal antibody directed against the oocyst wall. These protocols have been validated by interlaboratory trials with the participation of four laboratories involved in the same project. We have subsequently sought to better understand the real risks for consumers by undertaking a study of Reverse transcriptase PCR in parallel with in vivo, thus allowing to correlate the viability of parasites with their infectivity. This work contributes to a better control of health risks associated with food and presence of parasites, through a strategythat could be standardized and offered to industrial partners.

Les peptides antimicrobiens sont des éléments clés des mécanismes d'immunité innée développés pour combattre les microorganismes. Parmi ceux-ci, il y a les peptides antifongiques dont l'un, la mytimycine (MytM), avait été partiellement décrite chez la moule Mytilus edulis. Les buts de cette thèse consistaient en la caractérisation complète de la MytM chez M. edulis et chez M. galloprovincialis, ainsi qu'en la compréhension du rôle de ce peptide dans l'immunité de la moule. Les résultats montrent (i) une diversité des séquences nucléotides et en acides aminés en fonction de l'origine géographique des moules, résultant probablement d'une adaptation aux conditions environnementales; (ii) que 2 gènes différents codant la MytM sont simultanément présents dans le génome d'une même moule; (iii) que le niveau d'expression du gène de la MytM dépend de la nature du stimulus, suggérant l'existence de processus de reconnaissance spécifiques; et (iv) que le niveau d'expression du gène de la MytM varie d'une moule à l'autre. En conclusion, la MytM joue un rôle essentiel et spécifique chez la moule. Les données apportées par cette thèse enrichissent notre connaissance sur l'immunité innée des invertébrés. / Antimicrobial peptides are crucial elements of the innate immune mechanisms developed to fight microorganisms. Among them are antifungal peptides from which one, named mytimycin (MytM), had been partially reported in the blue mussel, Mytilus edulis. The purposes of this thesis were to fully characterize MytM in M. edulis and M. galloprovincialis and to understand how this peptide participates in mussel immunity. Results showed (i) the diversity of MytM mRNA and translated amino acid sequences according to geographic origin of mussels, probably resulting from adaptation to their environments; (ii) that 2 different MytM genes are simultaneously present in the genome of the same individual mussel; (iii) that expression level of MytM gene depends on the nature of the challenge, suggesting specific recognition processes; and (iv) MytM expression level was different from one mussel to another. In conclusion, MytM appeared to play a prominent and specific role in mussels. The advancement of our works added new data to the knowledge of innate immunity in invertebrates.

Orientadores: Solange Cadore, Sergio Luis Costa Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-08T00:57:22Z (GMT). No. of bitstreams: 1 Carvalho_RitaMariaWesteNano_D.pdf: 2677135 bytes, checksum: 453aee11d8c1855bb96aa0236c654c2d (MD5) Previous issue date: 2006 / Resumo: A poluição dos mares, baías e estuários provocada pela emissão de efluentes industriais e residenciais contendo íons metálicos é um dos principais fatores que favorece a contaminação dos moluscos bivalves. Esses organismos sofrem de maneira intensa a bioacumulação de íons metálicos, mesmo em baixas concentrações, tornando-se muitas vezes impróprios para o consumo humano e, além disso, podem refletir o grau de contaminação ambiental. Métodos de digestão com aquecimento assistido por microondas (MW) e com bloco digestor (BD) foram desenvolvidos para a determinação de íons metálicos em tecido de moluscos bivalves, por Espectrometria de Emissão Óptica em Plasma com Acoplamento Indutivo (ICP OES). Um planejamento de misturas do tipo simplex-centróide foi utilizado para estudar o efeito dos reagentes HNO3, HCl e H2O2 nos dois métodos. A análise de material de referência certificado de tecido de ostra (SRM 1566b - NIST) em condições instrumentais otimizadas e nos comprimentos de onda selecionados, apresentaram recuperação dos íons estudados entre 90 - 105%, para o método de digestão com aquecimento assistido por MW, e entre 90 - 100% para o método de digestão com aquecimento no BD. A eficiência das digestões foi avaliada pela determinação do carbono orgânico total (TOC) presente na solução, obtendo-se uma variação de 0,05 a 0,64%. A acidez das soluções variaram de 1,3 a 5,6% sendo que as soluções provenientes da digestão em forno de MW apresentaram menores valores comparados com a decomposição no bloco digestor. Usando o modelamento de misturas foi possível ajustar modelos matemáticos e determinar a composição adequada da mistura HCl - HNO3 - H2O2 para a decomposição de tecidos de moluscos bivalves. As proporções dos componentes foram 0,333: 0,333: 0,334 e 0,200: 0,200: 0,600 para digestão assistida por microondas e em bloco digestor, respectivamente. Os métodos empregados permitiram determinar macro e microconstituintes em tecidos de moluscos, constituindo-se em importantes ferramentas a serem empregadas para a solução de problemas ambientais / Abstract: The pollution of oceans, bays and estuaries as a result of industrial and domestic effluents that contain metallic ions is one of the most important factors that lead to the contamination of bivalve molluscs. These organisms are greatly affected by the bioaccumulation of inorganic species, even at low concentrations, reflecting the environmental contamination level. Under these conditions the ingestion of this kind of food is not recommended. Digestion methods based on heating in a microwave oven (MW) or with a digester block BD) for the subsequent determination of metallic ions in bivalve tissues by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) were developed. Mixtures planned using a simplex-centroide program were to study the effect of the reagents HNO3, HCl e H2O2 in both methods. The analysis of a certified reference material of oyster tissue (SEM 1566b - NIST) under the optimized instrumental conditions at the selected wavelengths showed recoveries of 90 -105%, for digestion by MW and of 90 -100%, for digestion by BD. The efficiency of digestion was evaluated by the determination of total organic carbon (TOC) remaining in the solution and values between 0.05 and 0.64% were obtained. The digestion using MW heating showed lower values compared with BD decomposition. Using the modelling of the mixtures it was possible to determine the most adequate composition of HCl-HNO3-H2O2 mixture for the decomposition of bivalve mollusc tissues. The ratios of mixtures were: 0.333:0.333:0.334, for MW digestion and 0.200:0.200:0.600 for BD digestion. The developed methods allowed the determination of macro and microconstituents in mollusc tissues and are important tools for environmental studies / Doutorado / Quimica Analitica / Doutor em Ciências

Re-creation and building new small freshwater habitats belong among the important management activities within the Protected Landscape Area Kokořínsko - Máchův kraj (Czech Republic) for almost two decades. These pools keep the water within the landscape and serve as the habitats for vulnerable species of amphibians and invertebrates, which I have studied within this thesis. Most studies focusing on studying metacommunities of small water bodies have been based on the data from one or two seasons, and thus completely neglect the development of composition of these metacommunities over longer periods of time. This thesis builds on previous research on the species composition of small ponds in the Kokořínsko Protected Landscape Area, which had been done in 2005 and 2006. In 2009 and 2017, sampling in the same ponds continued. I investigated the influence of spatial and environmental variables of individual ponds on the species composition of ostracods, copepods and molluscs in specific years and how has the representation of individual species changed among those years. With one exception, I have not observed any new incoming species of copepods and ostracods since 2006; the number of species had in fact decreased. In the case of molluscs, there was a significant exchange of species between individual...

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O Sistema Laguna-Barreira III é o sistema deposicional pleistocênico mais preservado do sul da Planície Costeira do Rio Grande do Sul. A origem dessa unidade está correlacionada ao alto nível do mar do último estágio interglacial, mas até agora pouco se conhece sobre sua evolução e estratigrafia devido à escassez de afloramentos. Uma assembleia de fósseis constituída por milhares de bivalves e gastrópodes foi recuperada de perfurações e sondagens SPT (Standard Penetration Test), em profundidades de até 17 metros, realizadas sobre essa unidade. A caracterização desses fósseis e a análise dos sedimentos e dos dados dos SPTs permitiu identificar depósitos de retrobarreira representando uma sequência retrogradacional caracterizada por fácies de fundo e margem lagunar sobrepostas por fácies eólicas arenosas, recobertas por depósitos de loess. A assembleia de fósseis, encontrada em depósitos de fundo e margem lagunar, é dominada por moluscos bivalves e gastrópodes, em sua maioria característicos de ambiente marinho franco raso (≤ 30 metros), mas também inclui alguns bivalves típicos de ambiente lagunar, como Erodona mactroides e Anomalocardia brasiliana A presença de espécies que não vivem atualmente nessa região sugere a influência de águas costeiras mais quentes durante o último estágio interglacial. O bom estado de preservação da maior parte da assembleia de moluscos, sem sinais de abrasão, bioerosão ou incrustação, indica curto tempo de residência na interface sedimento-água após a morte, seguido por rápido soterramento abaixo da Zona Tafonomicamente Ativa (TAZ). A presença de espécies marinhas juntamente com espécies de ambientes mixohalinos de baixa energia indica o transporte de sedimentos e fauna marinhos para a retrobarreira, o que teria ocorrido durante a fase transgressiva da evolução do Sistema III. Esse processo poderia estar relacionado ao aumento de tempestades durante o último interglacial, promovendo o transporte de grandes quantidades de sedimentos e conchas da face praial para a retrobarreira através de sobrelavagem da barreira (overwash) e abertura de inlets efêmeros. / The Barrier-Lagoon System III is the most preserved Pleistocene depositional system in the southern Coastal Plain of Rio Grande do Sul. The origin of this unit is correlated to the sea-level highstand of the last interglacial stage, but so far very little is known about the evolution and stratigraphy of this unit due to the scarcity of outcrops. A fossil assemblage consisting of thousands of bivalve and gastropod shells were recovered from drilling holes and SPT (Standard Penetration Test) surveys performed at depths up to 17 meters on that unit. The characterization of these fossils in addition to the analysis of the sediments and SPT data allowed to identify backbarrier deposits representing a retrogradational sequence characterized by lagoon bottom and margin facies superposed by sandy aeolian facies, covered by loess deposits. The fossil assemblage found in the lagoon bottom and margin deposits is dominated by bivalve and gastropod molluscs, mostly characteristic of open marine, shallow (≤ 30 meters) environment, but including some Erodona mactroides and Anomalocardia brasiliana, bivalves typical of lagoon environments The presence of species that do not currently live in the region suggests the influence of warmer coastal waters during the last interglacial stage. The good state of preservation of a large part of the molluscan assemblage, with no signs of abrasion, bioerosion or incrustation, indicates short residence time at the sediment-water interface after death, followed by rapid burial below the Taphonomically Active Zone (TAZ). The presence of marine species together with species from low energy mixohaline environments indicates the transport of sediments and marine fauna to the backbarrier, which would have occurred during the transgressive phase of the System III evolution. This process could have been related to increased storminess during the last interglacial, which promoted the transportation of large amounts of sediments and shells from the shoreface to the backbarrier through overwash and opening of ephemeral inlet channels.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-14T12:00:59Z No. of bitstreams: 1 Isabela Bacalhau de Oliveira.pdf: 896610 bytes, checksum: 7b6da45a1ce490a0cec723d5d43865eb (MD5) / Made available in DSpace on 2017-02-14T12:00:59Z (GMT). No. of bitstreams: 1 Isabela Bacalhau de Oliveira.pdf: 896610 bytes, checksum: 7b6da45a1ce490a0cec723d5d43865eb (MD5) Previous issue date: 2010-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aimed to analyze the spatial and temporal distribution of the clam Anomalocardia brasiliana and evaluate the stock recovery of this species in relation to the clam number and size after extraction in summer and winter in Mangue Seco, Pernambuco. In the first study, the beach (1800 m) was divided into three sections (S): S1 0 to 600m, S2 600 and 1200m and S3 1200 to 1800m. During this research a total of 1,016 specimens were collected in January (summer) and August (winter) of 2009, corresponding to 636 clams collected in the summer and 380 in the winter. The maximum density recorded in the summer period were 414.91 ± 82.48 ind.m-² at S3 and 323.49 ± 90.11 ind.m-² at S1, both were significantly different from S2 (156.12 ± 28.72 ind.m-²). In winter, the lowest densities were observed with 102.67 ± 5.07 ind.m-² and 122.37 ± 36.86 ind m-² for S1 and S2, respectively, both significantly different from S3 (296.76 ± 45.20 ind.m-²). The second study evaluated three treatments corresponding to an area of 18.75 m² each, where: the clams were removed manually by the fishers, collected using a fishing gear, and where there was no harvesting of clam. The sampling of the clams in these treatments was conducted in three moments: before extraction by fishers, after an hour and after 24 hours. Clams showed a smaller size (15.46 ± 0.86 mm) after manual collecting, but no significant difference in the size of the animals was found after the collection with the fishing gear (18.16 ± 0.92 mm). The number of the animals collected with size larger than 20 mm was greater than 80% in the winter and lower than 20% in the summer, without significant differences between the collection type tested for both seasons. The A. brasiliana showed a characteristic spatial distribution, with a greater abundance of juveniles during the summer while the adults were more abundant during the winter. The collection type and the extraction period did not influence the clam amount, as the stock of A. brasiliana in Mangue Seco is still quite dense and probably has the capacity to reconstitute itself after a period of 24 hours without clam extraction. The winter and summer seasons have a great influence on the abundance of A. brasiliana, with the largest number of animals within the recommended fishing size (> 20 mm) during the winter. / O presente estudo objetivou analisar a distribuição espaço-temporal do marisco Anomalocardia brasiliana e avaliar a recomposição do estoque desta espécie em relação ao número e ao tamanho dos mariscos capturados no verão e inverno na praia de Mangue Seco, Pernambuco. No primeiro estudo, a linha de praia (1.800 m) foi dividida em três trechos (T), sendo T1 de 0 a 600m, T2 de 600 a 1200m e T3 de 1200 a 1800m. Durante a pesquisa foram coletados um total de 1.016 espécimes nos meses de Janeiro (verão) e Agosto (inverno) de 2009. Desse total, 636 mariscos foram coletados no verão e 380 no inverno. Os valores máximos de densidade registrados no período de verão foram 414,91 ± 82,48 ind.m-² no T3 e 323,49 ± 90,11 no T1, sendo ambos diferentes significativamente do T2 (156,12 ± 28,72 ind.m-²). No inverno ocorreram os menores valores de densidade com 102,67 ± 5,07 ind.m-² e 122,37 ± 36,86 ind,m-² para T1 e T2, respectivamente, ambos diferindo significativamente do T3 (296,76 ± 45,20 ind.m-²). No segundo estudo foram avaliados três tratamentos correspondendo a uma área de 18,75m² cada, onde: os mariscos foram retirados manualmente pelas pescadoras, coletados com auxílio de um apetrecho de pesca, e onde não houve a coleta de mariscos. A amostragem dos mariscos nestes tratamentos foi realizada em três momentos: antes das coletas pelas marisqueiras, após uma hora e 24 horas após estas coletas. Foram observados mariscos com tamanho menor (15,46 ± 0,86 mm), após a coleta manual, sem diferença significativa entre o tamanho dos animais encontrados após a coleta com o apetrecho (18,16 ± 0,92 mm). A quantidade de animais capturados com tamanho maior que 20 mm foi superior a 80% no inverno, e inferior a 20 % no verão, sem diferença entre os tipos de coleta para ambas as estações. Os indivíduos da espécie A. brasiliana apresentaram uma distribuição espacial característica, com uma maior abundância de juvenis no período de verão enquanto que os adultos foram mais abundantes no período de inverno. O tipo de coleta avaliado e o momento da extração não influenciaram na quantidade de mariscos, visto que o estoque de A. brasiliana da praia de Mangue Seco ainda é bem denso e tendo capacidade de se recompor após um período de 24h da atividade de coleta pelas marisqueiras. As estações de inverno e verão exercem influencia na abundância de A. brasiliana, com maior quantidade de mariscos com tamanho recomendado para pesca (> 20 mm) no período do inverno.