81 resultados para Ecologia humana - Brasil.


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The contamination of aquatic environments is a phenomenon that dates back the origins of human civilizations and was amplified by the advent of industrial processes. The Jundiaí river , Macaíba's main water source, suffering discharge of effluents from various industries. The study work´s in two fronts, the environmental perception front was conducted through semistructured interviews whose textile effluent was appointed by the population as the main problem in the river. It was observed that nearly all respondents had concerns about the environment. In addition, there is an inclusion of individuals as the cause of the problem, because a significant part recognizes that its activities may cause damage to the environment and people's health. In other front, the experimental monitoring of water quality was conducted through ecotoxicological tests and physiochemical analysis that proposed to assess Pomacea lineata .Mysidopsis juniae isolated effect of textile effluent and its influence on the river compared with the limits established by Brazilian law. Although the physio-chemical analysis shows is inconclusive about the participation of the textile effluent in environmental contamination of the river, the ecotoxicological tests have shown to blunt the signal that the effluent may present a risk to aquatic organisms and consequently to human health. Thus, an interdisciplinary way it was possible to study the cause of the environmental problem identified by the population in the realization phase and measurable effect on water quality analysis in the river by means of the tests mentioned.

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The trophic ecology studies issues related to the diet of individuals within a community .The relation between the body size of the predator and the prey size, individual specialization and niche breadth are some of the issues that can be discussed by it .I collected the lizards using pitfall trap, glue and active collecting traps in a fragment of Caatinga. The most common species in this community were Tropidurus hispidus, T. semitaeniatus and Cnemidophorus ocellifer. The visits to the farm also relied on collecting invertebrates at each season to understand how the nutritional resources of lizards were presented in each one of them. I tried to answer some questions : 1) If there was a positive relation between body size of the predator and the size of prey of the community ; 2) If in different seasons the relation of body size of the predator and the maximum and/or minimum size of the prey would be positive ; 3) If species with different foraging strategies have positive relation on the size of the predatorprey relation; 4) If the seasonality would influence on the individual expertise of lizards community and more common species; 5) If the breadth of the niche would be influenced by seasonality ; 6) If more individuals with different morphology between them would present less similar diet. I found that there was indeed a positive relationship between size of prey and predator, but nonexistent related to the minimum size of prey; Among the seasons relative size of predators and prey was different for the maximum and minimum size, but was positively related only to the size of the maximum prey. And comparisons between different foraging strategies had the maximum and minimum line inclination greater than zero and different from each other; individual specialization was not influenced by seasonality and the niche breadth was wider in the dry season only to T. semitaeniatus. At last I didn't find a significant negative relationship between morphological dissimilarity and similarity of diet.

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This work has as object the elaboration of social environmental indicator of disaster risk that are present in precarious areas of human occupation, related to intense environmental dynamic from the perspective of the studies about the subject in Geography. The District of Mãe Luiza in Natal, capital city of Rio Grande do Norte, was defined as the study area. The place was chosen because it presents –historically- several vulnerability conditions and exposure to disaster risk. After a local social environmental description, two indexes were elaborated: the Social Vulnerability Index (SVI or IVS in Portuguese), based on 17 (seventeen) variables arranged on a questionnaire addressed to the population nucleus of the district, on regular grid (systematic sampling), classified into 5 (five) levels of SV from the weighted average; and the Physical and Natural Exposure to the Mass Movements Index (EMMI or IEMM in Portuguese) which had 16 (sixteen) variables that feature conditions of exposure to the mass movements in the district with classified levels from the weighted average of 1 (one) to 5 (five). The relationship between these two results, specialized in the district map, produced the Social Environmental Vulnerability Index (SEVI or IVSA in Portuguese) of Mãe Luiza, also classified into 5 (five) levels, following the Boolean logic correlation for cartographic overlay with use of computer software ArcGIS v.9.3, being named as: Very Low; low; average; high; and Very High Environmental Vulnerability in District. The study is based on the methodology proposed by Guerra et al (2009) for EMMI and by Almeida (2010) for SVI. They were modified and adapted according to the local reality, producing a new methodology in this study area. It was concluded that the neighborhood has most of its area with High and Very High Socio-environmental vulnerability to disasters, defined seven (7) critical areas, with Very High IVSA, and hazards associated with mass movements or flooding. In the end, the main issues that were found, such as generating elements for proposing mitigation measures and/or the proposed interventions were enumerated, related to structural order of vulnerability factors: how low constructive pattern of households; poor urban drainage; Real Estate forsaken in landslide routes; infrastructure ready access roads and slope containment. And social: as a lack of education about environmental risk; income and education of residents; presence of persons with limited mobility and/or those with special needs. This reality highlights the need for urgent action applied to the resolution and/or reduction of these problems, which is focusing the end of this work.

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A família Gobiidae é a mais diversificada no ambiente marinho, onde tamanha diversidade parece ter sido acompanhada por alterações cromossômicas significativas, a tornando um modelo biológico importante. Em geral apresentam ampla distribuição geográfica com características comportamentais e reprodutivas que as tornam propícias aos efeitos de barreiras biogeográficas. Comparados a outros representantes da ordem Perciformes apresenta características morfológicas reduzidas, com simplificações e perdas que dificultam estudos filogenéticos e tornam imprescindível a associação de novas metodologias para melhor entendimento dos processos ecológicos e evolutivos que garantiram tamanha diversificação. Dados citogenéticos para espécies presentes no litoral brasileiro são ínfimos. Os resultados aqui apresentados, abrangendo um maior espectro taxonômico e profundidade de análises, identificaram marcante diversidade cariotípica estrutural interespecífica para Coryphopterus glaucofraenum, Bathygobius mystacium, Bathygobius soporator, Bathygobius sp., Ctenogobius smaragdus, Ctenogobius boleosoma, Gobionellus oceanicus, Gobionellus stomatus, Microgobius meeki e Evorthodus lyricus. As espécies estudadas fazem parte de uma fauna críptica pouco percebida e estudada, frequentemente impactadas, mesmo por eventos locais estocásticos. Análises por morfometria geométrica indicaram variação significante na morfologia corporal de espécies do gênero Bathygobius e o reconhecimento de padrões de variação de forma corporal referentes ao sexo, com populações mais dimórficas em menores latitudes. Técnicas citogenéticas moleculares resolutivas aplicadas em estudos populacionais no litoral e em ilhas oceânicas identificaram diferenciações locais e reconheceram uma nova espécie para o gênero Bathygobius, residente no Atol das Rocas e Arquipélago de Fernando de Noronha. As análises ainda possibilitaram a descrição de cromossomos sexuais XY nas duas espécies do gênero Gobionellus e a participação de elementos repetitivos na diferenciação deste sistema. Os dados aqui apresentados dão suporte ao alto grau de diversificação evolutiva da família, ampliam o conhecimento citogenético para o grupo, permitem identificar estruturações populacionais e respostas evolutivas das espécies às variações geográficas. Como modelo biológico a família Gobiidae representa um útil contraponto evolutivo em relação aos padrões genéticos vigentes às espécies de grande vagilidade.

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Le present travail a pour objectif, discuter le dialogue entre deux des formes de penser le processos santé-maladie: la médécine traditionnelle et celle scientifique. Et cette dernière représentée par le Système Unique de Santé, particulièrement par une Équipe de Santé de la Famille. Partant du questionnement “quel est le rôle de chaque système de santé dans les problèmes sanitaires ainsi que dans la prévention des maladies?”, il s‟agit de vérifier si l‟ ”Écologie des Savoirs” discutée par Santos (2007) a été appliquée dans les deux manières de penser et pratiquer les politiques de santé; tenant em compte que chacune d‟elles ayant son champ de possibilites et d‟impossibilités agit directement sur le quotidien des aires géographiques concernés par la recherche: le District de São João do Abade dans le Municipe de Curuçá/PA et l‟Équipe de Santé de la Famille Abade localisée dans ce même district. Cette étude fut réalisée à partir d‟instruments de collecte de données comme la recherche de terrain, l‟observation directe et les interviews semi-structurés (HAGUETTE, 1997) e apports théoriques à partir de certains des concepts clés les plus utilisés par les Épistémologies du Sud où nous mettons en relief l' “Écologie des Savoirs” (Santos, 2007); le “travail de Traduction” (SANTOS, 2008); la “Sociologie des Absences et la Sociologie des Émergences” (SANTOS, 2004); le concept de “Santé-Maladie” (MINAYO, 1988); ainsi que les discussions autor des “Savoirs de la Tradition” (ALMEIDA, 2010; RAMALHO et ALMEIDA, 2011). La stratégie “Santé de la Famille fut pensée à travers la vision de Guedelha (2008) et Vilar et al. (2011) où à partir de cette dernière la discussion sur le concept de “Médécine Communautaire” (DONNANGELO e PEREIRA, 1976) comme recours importante dans la recherche de l‟ “Écologie des Savoirs” dans la Stratégie Santé de la Famille a été possible.

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While the carnivores are considered regulators and structuring of natural communities are also extremely threatened by human activities. Endangered little-spotted-cat (Leopardus tigrinus) is one of the lesser known species from the Neotropical cats. In this work we investigate the occupancy and the activity pattern of L. tigrinus in Caatinga of Rio Grande do Norte testing: 1) how environmental and anthropogenic factors influence their occupation and 2) how biotic and abiotic factors influence their activity pattern. For this we raised occurrence data of species in 10 priority areas for conservation. We built hierarchical models of occupancy based on maximum likelihood to represent biological hypotheses which were ranked using the Akaike Information Criterion (AIC). According to the results the feline occupancy is more likely away from rural settlements and in areas with a higher proportion of woody vegetation. The opportunistic killing of L. tigrinus and in retaliation for poultry predation close to residential areas can explain this result; as well as more complex vegetation structure can better serve as refuge and ensure more food. Analyzing the records of the species through circular statistics we conclude that the activity pattern is mostly nocturnal, although considerable crepuscular and a small diurnal activity. L. tigrinus activity was directly affected by the availability of small terrestrial mammals, which are essentially nocturnal. In addition, the temperatures recorded in the environment directly and indirectly affect the activity of the little-spotted-cat, as also influence the activity of their potential prey. Generally, the cats were more active when possible prey were active, and this happened at night when lower temperatures are recorded. Moreover, the different lunar phases did not affect the activity pattern. The results improve the understanding of an endangered feline inhabiting the Caatinga biome, and thus can help develop conservation and management strategies, as well as in planning future research in this semi-arid ecosystem.

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Feeding is the primary selective pressure in all forms of animals. Nutritional ecological models predict consequences of preferred and non-preferred food consumption on behavioural, physiological and morphological adaptations. At same time, socioecological models infer socio-organizarion patterns based on feeding competition faced by animals. A list of preferred foods, and inferences regarding the intensity of feeding competition and its behavioural consequences are information of much importance for management of populations in fragments. In this work we observed the feeding behavior and spatial positioning of a group of more than 100 blond capuchin monkeys (Sapajus flavius) that inhabit a fragment of Atlantic forest, surrounded by sugarcane plantation. We compared the consumption of different food items with their monthly availability in the area to define the preferred and fallback food items. We recorded the vocalizations of aggression and the inter-individual distance (area of Minimum Convex Polygon/n individuals) to infer the type of food competition experienced by animals. In the year studied the fruit feeding time correlated with top consumed fruit productivity, indicating preference for fruits. Our data indicate that the species Elaeis sp., Cecropia palmata, Inga spp. and Simarouba amara are the preferred food items in the diet. Available all year round and uniformly distributed, sugarcane was a regular item in the diet and its was characterized as a staple fallback food for this group. Although fruits are preferential food items, direct competition rate did not correlate to fruit productivity in the area, maintaining the high rates throughout the year (2.45 events/ hour). The inter-individual distance index positively correlated with rain fall indicating scramble food competition. The number of neighbours of females carrying infants was smaller when fruit productivity is low, indicating that females carrying infants are suffering increased indirect competition. Our data indicates that blond capuchins in this fragment make use of sugar cane as a staple fallback food, which evidence the importance of sugar cane landscape for the survival of this critically endangered capuchin species in fragmented habitats in Northeast Brazil. A preliminary list of preferred and important foods is offered, and can assist in the choice of trees for reforestation, better fragments to be preserved and areas of release and translocation of animals. We did not observe an increase of contest competition while using preferred foods, but when using staple FBF. This may be due the altered environment, which results in high competition food throughout the year. Both the food preference as the social and behavioral consequences of high food competition experienced by animals in this fragment must be accompanied over the years to ensure the survival of this population.

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Feeding is the primary selective pressure in all forms of animals. Nutritional ecological models predict consequences of preferred and non-preferred food consumption on behavioural, physiological and morphological adaptations. At same time, socioecological models infer socio-organizarion patterns based on feeding competition faced by animals. A list of preferred foods, and inferences regarding the intensity of feeding competition and its behavioural consequences are information of much importance for management of populations in fragments. In this work we observed the feeding behavior and spatial positioning of a group of more than 100 blond capuchin monkeys (Sapajus flavius) that inhabit a fragment of Atlantic forest, surrounded by sugarcane plantation. We compared the consumption of different food items with their monthly availability in the area to define the preferred and fallback food items. We recorded the vocalizations of aggression and the inter-individual distance (area of Minimum Convex Polygon/n individuals) to infer the type of food competition experienced by animals. In the year studied the fruit feeding time correlated with top consumed fruit productivity, indicating preference for fruits. Our data indicate that the species Elaeis sp., Cecropia palmata, Inga spp. and Simarouba amara are the preferred food items in the diet. Available all year round and uniformly distributed, sugarcane was a regular item in the diet and its was characterized as a staple fallback food for this group. Although fruits are preferential food items, direct competition rate did not correlate to fruit productivity in the area, maintaining the high rates throughout the year (2.45 events/ hour). The inter-individual distance index positively correlated with rain fall indicating scramble food competition. The number of neighbours of females carrying infants was smaller when fruit productivity is low, indicating that females carrying infants are suffering increased indirect competition. Our data indicates that blond capuchins in this fragment make use of sugar cane as a staple fallback food, which evidence the importance of sugar cane landscape for the survival of this critically endangered capuchin species in fragmented habitats in Northeast Brazil. A preliminary list of preferred and important foods is offered, and can assist in the choice of trees for reforestation, better fragments to be preserved and areas of release and translocation of animals. We did not observe an increase of contest competition while using preferred foods, but when using staple FBF. This may be due the altered environment, which results in high competition food throughout the year. Both the food preference as the social and behavioral consequences of high food competition experienced by animals in this fragment must be accompanied over the years to ensure the survival of this population.

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The thrush beach, Mimus gilvus (Aves: Mimidae) is a passerine widely distributed in Central and South America. In Brazil occurs mainly in the areas of the resting and vegetation near the beach. In southeastern Brazil this species has disappeared, mainly due to urbanization. Many attributes of their reproductive biology are unknown, especially in relation to reproductive success. During the years 2010-2011, 2011-2012 and 2014-2015 were made visits to the area of restinga forest in Centro de Lançamento da Barreira do Inferno (CLBI), located between the cities of Natal and Parnamirim-RN (5 ° 54'S 35 ° 10'W ) where they were made systematic searches to trying describe reproductive biology of the characteristics of M. gilvus, estimate their reproductive success using the Mayfield method, and identify the main factors that influence their reproductive success in environment the resting. For this, forty fifth active nests monitored were used. Only during the breeding season of 2011-2012 and 2014-2015 were made systematic visits to the study area. The reproductive period ranged August to March. Clutch size ranged from two, three and six eggs (n = 22). Broods of two eggs were more common, with an average of eggs laid per nest of 2 ± 0,51 (n = 20 nests). The incubation period was approximately 13 ± 1,9 days (n = 11 nests). The period of stay of the nestlings was approximately 11 ± 1,6 days (n = 9 nests). With approximately 11 days old the nestlings were able to leave the nest. The apparent success was 37,8% and the success estimated by Mayfield method was 26,6%. Predation was the main cause of loss of nests in the study area. The daily survival rates (TDS) were obtained from 0,9593 incubation and 0,9313 for nestling period respectively. Survival estimates for each period was 0,5827 for incubation and 0,4571 for nestling period. The cumulative average rainfall for each month influenced negatively the hatching rates of M. gilvus nests. In addition, the number hatch eggs among the most rainy season (rainy season) and the period of lowest rainfall (dry season) were different. The number of lost nests of M. gilvus was lower in scrubs than cactus, which may account for the largest number of nests of this species found in scrubs. Survival rates in nestling period were lower compared with the incubation period. The fact that the survival rates nests of M. gilvus be lower in the nestling period compared to the incubation period may result from increased activity of adults during this phase of the nest, which in turn would increase predation rates. M. gilvus seems to avoid the rainy season during their reproduction, concentrated most of their nests in periods of low rainfall.

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A disponibilidade de cadáveres para estudo e pesquisa vinha sendo feita tradicionalmenteutilizando-se corpos não reclamados sem grandes formalidades. Com a complexidadejurídica, social, ética e moral dos tempos atuais, o simples encaminhamento dessescorpos ao Departamento de Morfologia da Universidade Federal do Rio Grande do Norte,passou a ser temido com o receio de transgredir a legislação penal. Isso desencadeouuma redução no número de cadáveres para as aulas práticas de Anatomia. Essarealidade levou o Departamento de Morfologia da Universidade Federal do Rio Grande doNorte a pesquisar mecanismos legais que solucionassem a escassez de cadáveres parao estudo e pesquisa. A metodologia utilizada constou de reuniões de discussão eapresentação de protocolos de aquisição de cadáveres com base na legislação vigente.Os resultados obtidos foram: (1) Publicação do provimento 093/2012 da CorregedoriaGeral da Justiça do Tribunal de Justiça do Estado do Rio Grande do Norte, que dispõesobre o registro de óbito dos cadáveres destinados às escolas de Medicina para fins deensino e pesquisa; (2) Elaboração de protocolos para aquisição de cadáveres nãoreclamados junto às instituições; (3) Programa de doadores voluntários na UniversidadeFederal do Rio Grande do Norte.Por fim, concluímos que o conhecimento das atribuiçõespor parte das instituições públicas e privada, bem como o programa de doação voluntáriaaumentaram a oferta de cadáveres para o ensino da Anatomia Humana na UniversidadeFederal do Rio Grande do Norte.

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Sea urchins are common benthic organisms on coastal ecosystems of tropical and temperate shallow waters. The impact of sea urchins populations in shore communities is density-dependent, and therefore, knowledge of the life history of these animals is important to understand these interactions. Between 2000 and 2005 a population boom of Tripneustes ventricosus was observed in the Fernando de Noronha Archipelago. In 2004 a research program was started to monitor the population dynamics of T. ventricosus in the archipelago, when it noted a lack of basic information on the biology and reproduction of this species, despite its broad geographic distribution and economic importance in parts of its occurrence. In this context, this work focuses on the reproductive biology of T. ventricosus with emphasis on the description of the gametogenic stages. Between December 2006 and July 2007, ten urchins were collected by snorkeling in two sites of the archipelago, totaling 120 individuals. Gametogenic stages were described for both sexes through microscopic analysis, and were defined as: Recovery, Growing, Premature, Mature and Spawning. Results showed increasing in Gonad index throughout of months of sampling and suggest that the reproductive cycle of the species in the archipelago is annual

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The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ß-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains

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The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species

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Spatial-temporal dynamics of zooplankton in the Caravelas river estuary (Bahia, Brazil). The survey was conducted in order to describe the zooplankton community of the estuary Caravelas (Bahia, Brazil), to quantify and relate the patterns of horizontal and vertical transport with the type of tide (neap and spring) and tidal phase (flood and ebb). Zooplankton samples were collected with the aid of a suction pump (300L), filtered in plankton nets (300μm) and fixed in saline formalin 4%. Samples were collected at a fixed point (A1), near the mouth of the estuary, with samples taken at neap tides and spring tides during the dry and rainy seasons. Samples were collected for 13 hours, at intervals of 1 hour in 3 depths: surface, middle and bottom. Simultaneous collection of biological, we measured the current velocity, temperature and salinity of the water through CTD. In the laboratory, samples were selected for analysis in estereomicroscope, with 25 groups identified, with Copepoda getting the highest number of species. The 168 samples obtained from temporal samples were subsampled and processed on equipment ZooScan, with the aid of software ZooProcess at the end were generated 458.997 vingnettes. 8 taxa were identified automatically, with 16 classified as a semi-automatic. The group Copepoda, despite the limited taxonomic refinement ZooScan, obtained 2 genera and 1 species identified automatically. Among the seasons dry and wet groups Brachyura (zoea), Chaetognatha, and the Calanoid copepods (others), Temora spp., Oithona spp. and Euterpina acutifrons were those who had higher frequency of occurrence, appearing in more than 70% of the samples. Copepoda group showed the largest percentage of relative abundance in both seasons. There was no seasonal variation of total zooplankton, with an average density of 7826±4219 org.m-3 in the dry season, and 7959±3675 org.m-3 in the rainy season, neither between the types and phases of the tides, but seasonal differences were significant recorded for the main zooplankton groups. Vertical stratification was seen for the major zooplankton groups (Brachyura, Chaetognatha, Calanoida (other), Oithona spp, Temora spp. e Euterpina acutifrons). The scale of this stratification varied with the type (square or tide) and tidal phase (flood or ebb). The instantaneous transport was more influenced by current velocity, with higher values observed in spring tides to the total zooplankton, however, there was a variation of this pattern depending on the zooplankton group. According to the data import and export of total zooplankton, the outflow of organisms of the estuary was higher than the input. The results suggest that the estuary of Caravelas may influence the dynamics of organic matter to the adjacent coast, with possible consequences in National Marine Park of Abrolhos

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Guaraíras lagoon, located in Tibau do Sul in the eastern littoral of Rio Grande do Norte (Brazil), presents a permanent connection to the sea, which guarantees the occurrence of a rich biodiversity, which includes the autochthonous shrimp species Litopenaeus schmitti, Farfantepenaeus subtilis and Farfantepenaeus brasiliensis. In spite of being subject to a strong human intervention in the last decade, mainly related to the installation of shrimp (Litopenaeus vannamei) farms, the lagoon is still scarcely studied. The present study aims at characterizing the populations of the three autochthonous penaeid shrimp species inhabiting Guaraíras, taking into consideration their abundance and seasonal distribution in the inflow channel of Primar System of Organic Aquaculture (Tibau do Sul, Rio Grande do Norte, Brazil). Twelve monthly samples were carried out from May 2005 to April 2006 with the aid of a circular cast net in the inflow channel, which is daily supplied with water from Guaraíras. Sampling months were grouped in trimesters according to the total pluviosity, thus comprising four trimesters. Water salinity was monitored twice a week and temperature values registered on a daily basis at noon, during the study period. The daily pluviosity data from the municipality of Tibau do Sul were supplied by Empresa de Pesquisa Agropecuária do Rio Grande do Norte (EMPARN). Collected shrimp were identified, weighted, measured and sexed. L. schmitti specimens (0.2 g to 17.8 g) were distributed in 1.3 g weight classes intervals. From the eighth sampling month (December 2005) onwards, males were classified into three categories, in accordance with the development of their petasm: (a) rudimentary petasm, (b) partially formed petasm, and (c) completely formed petasm. Among the ecological variables, rainfall showed the greatest dispersion (s.d.=187.74Rainfall and abundance of L. schmitti were negatively correlated (r = -0.85) whereas its abundance and water salinity were positively correlated (r = 0.63). Among 1,144 collected individuals, 1,127 were L. schmitti, 13 were F. subtilis and 4 were F. brasiliensis, which corresponded to 98.51%, 1.14% and 0.35% of the total of collected individuals. L. schmitti occurred in 100 % of all samples. Differently, the presence of F. subtilis and F. brasiliensis was restricted to 33% and 17% of the collected samples, respectively. The present study confirmed the occurrence of L. schmitti, F. brasiliensis and F. subtilis in Guaraíras. However, this lagoon seems to be primarily inhabited by juvenile Litopenaeus schmitti. The population of L. schmitti analysed showed a seasonal pattern of distribution. In general, in the months of high salinity and absence of rain, the number of individuals was higher than in the wet months. Further studies on the reproductive biology and ecology of L. schmitti, F. brasiliensis and F. subtilis may elucidate questions referring to the abundance, period, and phase of occurrence of these shrimp genera in Guaraíras. Finally, the risks associated to the establishment of L. vannamei in the lagoon provide a novel outlet for studies in this biotope