1000 resultados para vegetal species


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Observations on bees visitors to three species of Clusia (Clusiaceae) flowers in the Reserva Adolpho Ducke, Manaus, Amazonas, Brazil were made during three two-week periods. The three species of Clusia, namely C. grandiflora, C. panapanari and C. insignis, presented variations regarding the species of bee visitors. A total of 23 bee species visited the three species of Clusia. The Euglossini and Meliponinae bees were the most frequent visitors of the Clusia flowers. Bee collecting behavior of floral resources is described.

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Previous study on the resistance of larvae of Sesarma curacaoense submitted to starvation has revealed a facultative lecithotrophy during zoeal stages, but megalopa and first juvenile stages are exclusively feeding stages. In the present study, the gross morphology and fine structure of the foregut of S. curacaoense were investigated during larval, megalopa and first juvenile stages. The foregut of the zoea I show specific setae and a filter press apparently functional. The foregut undergoes changes in the zoea II (last larval stage) with increment of setae number, mainly on the cardiopyloric valve and complexity of the filter press. After metamorphosis to megalopa stage the foregut become rather complex, with a gastric mill supporting a medial and two lateral teeth well-developed. The foregut of the first juvenile is more specialized compared to the previous stage, showing similar characteristics of the decapod adults. These results provide further evidence of facultative lecithotrophic development in the larvae of S. curacaoense.

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We investigate palm species distribution, richness and abundance along the Mokoti, a seasonally-dry river of southeastern Amazon and compare it to the patterns observed at a large scale, comprising the entire Brazilian territory. A total of 694 palms belonging to 10 species were sampled at the Mokoti River basin. Although the species showed diverse distribution patterns, we found that local palm abundance, richness and tree basal area were significantly higher from the hills to the bottomlands of the study region, revealing a positive association of these measures with moisture. The analyses at the larger spatial scale also showed a strong influence of vapor pressure (a measure of moisture content of the air, in turn modulated by temperature) and seasonality in temperature: the richest regions were those where temperature and humidity were simultaneously high, and which also presented a lower degree of seasonality in temperature. These results indicate that the distribution of palms seems to be strongly associated with climatic variables, supporting the idea that, by 'putting all the eggs in one basket' (a consequence of survival depending on the preservation of a single irreplaceable bud), palms have become vulnerable to extreme environmental conditions. Hence, their distribution is concentrated in those tropical and sub-tropical regions with constant conditions of (mild to high) temperature and moisture all year round.

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Coagulase-negative staphylococci (CoNS) are common bacterial colonisers of the human skin. They are often involved in nosocomial infections due to biofilm formation in indwelling medical devices. While biofilm formation has been extensively studied in Staphylococcus epidermidis, little is known regarding other CoNS species. Here, biofilms from six different CoNS species were characterised in terms of biofilm composition and architecture. Interestingly, the ability to form a thick biofilm was not associated with any particular species, and high variability on biofilm accumulation was found within the same species. Cell viability assays also revealed different proportions of live and dead cells within biofilms formed by different species, although this parameter was particularly similar at the intra-species level. On the other hand, biofilm disruption assays demonstrated important inter- and intra-species differences regarding extracellular matrix composition. Lastly, confocal laser scanning microscopy (CLSM) experiments confirmed this variability, highlighting important differences and common features of CoNS biofilms. We hypothesised that the biofilm formation heterogeneity observed was rather associated with biofilm matrix composition than with cells themselves. Additionally, our results indicate that polysaccharides, DNA and proteins are fundamental pieces in the process of CoNS biofilm formation.

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Mesovelia mulsanti White, 1879 and M. zeteki Harris & Drake, 1941 are newly recorded in the Amazon River floodplain, Brazil. A key to the three known species ocurring in this region is also provided. Mesovelia mulsanti can be distinguished from M. amoena and M. zeteki by the body length larger than 2.50 mm, the head without longitudinal brown stripes near midline, and the forefemur and midfemur of the male, which have ventral rows of spines. Mesovelia amoena differs from M. zeteki in aspects of body color and in number of spinules near posterior margin of abdominal sternite VI of male.

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A new species of the genus Cerqueirellum Py-Daniel, 1983 (Diptera: Simuliidae) is described. The adults are similar to the species C. oyapockense (Floch & Abonnenc, 1946) and C. roraimense (Nunes de Mello, 1974), of which the females are similar, and the males present discrete differences. The main differences of this new species to others of the genus Cerqueirellum are the integument of the larva recovered from stout spines and long cephalic trichomes in the pupa. Some females were infected with Mansonella ozzardii (Manson, 1897) (Nematoda, Onchocercidae) and probably transmit mansonelliasis in the Ituxi river, state of Amazonas, Brazil.

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The aim of this study was not only to determine the red blood cells parameters, thrombocyte and leukocyte counts in farmed Brycon amazonicus (matrinxã), to compare these parameters among Bryconinae species from literature, and also to investigate the presence of special granulocytic cells in these fish. The results of the blood cells parameters here established for farmed B. amazonicus, a species of great economic importance in Brazilian aquaculture, could help a better understanding of the blood features in natural populations of this Amazon species. Blood parameters varied between Bryconinae species investigated, mainly the red blood cell counts, hemoglobin, hematocrit and mean corpuscular volume (MCV). The presence of the blood granulocytes, neutrophils and heterophils in matrinxã suggest that both leukocytes can be a characteristic for Bryconinae family. Furthermore, it indicates that the existence of special granulocytic cells in the blood of Bryconinae species from literature is an artifact, and this was herein discussed.

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In this work, I apply a simple protocol to species occurrence inventory of Odonata in a region of Maranhão state which has very few distributional records. Some relations between species occurrence and environmental characteristics are discussed, mainly in relation to the high occurrence of Erythemis. Eighteen new records are presented discussing the role of this approach to generate useful information for conservation purposes.

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A new species of Protoptila Banks (Trichoptera: Glossosomatidae: Protoptilinae) - P. longispinata sp. nov. - is described and illustrated from specimens collected in Amazon region, Amazonas and Pará states, Brazil.

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The genus Actinella Lewis was studied using planktonic samples from a black water floodplain lake in Central Amazon region. For species identification the taxa were morphological and morphometricaly analyzed on base in light microscope (LM) and scanning electronic microscope (SEM). Five species were registered: Actinella brasiliensis Grunow, A. guianensis Grunow, A. gracile Kociolek, A. mirabilis (Eulenstein ex Grunow) Grunow and A. robusta Hustedt. A. gracile is reported for the first time for Amazon State and black water systems and it is firstly documented with SEM. In addition, a review of geographic distribution of Actinella species in Brazilian Amazon region is given.

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All species of Macrostomus Wiedemann allied with Macrostomus pictipennis (Bezzi), are treated in the pictipennis species-group. Three currently recognized species and four new species are included, namely M. cervicicauda Smith, M. cysticercus Smith, M. manauara, sp. nov. from Brazil (Amazonas and Pará states), M. pacaraima, sp. nov. from Brazil (Roraima, Amazonas and Pará states), M. pictipennis (Bezzi), M. smithi, sp. nov. from Guyana and Brazil (Roraima State) and M. utinga, sp. nov. from Brazil (Pará State). All primary types were examined and a key to species is presented.

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Seven new species of Lachesilla in the group forcepeta, from the Amazon Basin in Brazil, Colombia and Peru, are here described and illustrated: L. amacayacuensis sp. n. (type locality: Colombia, Amazonas, Leticia, Amacayacú); L.bulbosiforceps sp. n. (type locality: Peru, Cuzco); L. cuzcoensis sp. n. (type locality: Peru, Cuzco); L. marabaensis sp. n. (type locality: Brasil, Pará, Marabá, Serra Norte); L. pilosiforceps sp. n. (type locality: Brasil, Pará, Oriximiná, Rio Trombetas); L. pilosipenna sp. n. (type locality: Peru, Cuzco); L. squamiforceps sp. n. (type locality: Colombia, Amazonas, Leticia). The Amazon Basin is the second most rich world area for species of Lachesilla.

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Este estudo apresenta um mapa da cobertura vegetal da planície de inundação do Rio Amazonas entre as cidades de Parintins (AM) e Almeirim (PA), com base em imagens Landsat-MSS adquiridas entre 1975 e 1981. O processamento digital dessas imagens envolveu a transformação para imagens-fração de vegetação, solo e água escura (sombra), seguido da aplicação de técnicas de segmentação e classificação por região. O mapa resultante da classificação foi organizado em quatro classes de cobertura do solo: floresta de várzea, vegetação não-florestal de várzea, solo exposto e água aberta. A precisão do mapa foi estimada a partir de dois tipos de informações coletadas em campo: 1) pontos de descrição: para validação das classes de cobertura não sujeitas a grandes alterações, como é o caso dos corpos d'água permanentes, e identificação de indicadores dos tipos de cobertura original presentes na paisagem na ocasião da obtenção das imagens (72 pontos); 2) entrevistas com moradores antigos para a recuperação da memória sobre a cobertura vegetal existente há 30 anos (44 questionários). Ao todo foram coletadas informações em 116 pontos distribuídos ao longo da área de estudo. Esses pontos foram utilizados para calcular o Índice Kappa de concordância entre os dados de campo e o mapa resultante da classificação automática, cujo valor (0,78) indica a boa qualidade do mapa de cobertura vegetal da várzea. Os resultados mostram que a região possuía uma cobertura florestal de várzea de aproximadamente 8.650 km2 no período de aquisição das imagens.

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A multilocus mixed-mating model was used to evaluate the mating system of a population of Couratari multiflora, an emergent tree species found in low densities (1 individual/10 ha) in lowland forests of central Amazonia. We surveyed and observed phenologically 41 trees in an area of 400 ha. From these, only four mother trees were analyzed here because few of them set fruits, which also suffered high predation. No difference was observed between the population multilocus outcrossing rate (t mp = 0.953 ± 0.040) and the average single locus rate (t sp = 0.968 ± 0.132). The four mother trees were highly outcrossed (t m ~ 1). Two out of five loci showed departures from the Hardy-Weinberg Equilibrium (HWE) expectations, and the same results occurred with the mixed-mating model. Besides the low number of trees analyzed, the proportion of loci in HWE suggests random mating in the population. However, the pollen pool was heterogeneous among families, probably due to both the small sample number and the flowering of trees at different times of the flowering season. Reproductive phenology of the population and the results presented here suggest, at least for part of the population, a long-distance pollen movement, around 1,000 m.