27 research outputs found

    Proposal for rapid identification of the hydrological periods in lowland areas along the Solimões Amazon river in the proximity of Manaus

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    Seasonal variations of the water level is the most important factor in determining the community of aquatic organisms present in flooded areas in the Amazon. Many scientific projects developed in this region were and still are being carried out in flooded areas near the city of Manaus; however, data can rarely be compared due to a non-standardized nomenclature used to describe the various phases of the flood pulse. The present paper aims to identify and standardize the terminology used to define a hydrological cycle with the purpose of allowing for the analysis of data from different places and multiple years. Serial data of the Negro River water height taken from the local harbor was considered for the estimations. Values of the water height are proposed in order to define the four hydrological periods (rising, flood, lowing, dry) and the intensity of flood and dry periods. A typical, long and short hydrological period was also defined in number of days based on the duration of each period. Considering that environmental abiotic and biotic modifications are related to water level fluctuation, the standardization of the hydrological nomenclature may become a useful tool for ecological data analysis.A variação periódica do nível das águas é o principal fator que determina a comunidade de organismos aquáticos presente em rios com planícies alagadas. Muitos estudos na Amazônia são desenvolvidos nas várzeas próximas à cidade de Manaus, mas, comparações entre essas informações são dificultadas pela ausência de padronização na denominação das diferentes etapas do ciclo de cheia-seca. Este trabalho teve como objetivo a identificação e a padronização da nomenclatura das diferentes fases do ciclo hidrológico para possibilitar análises que envolvam resultados de mais de um ano e de mais de um local. Os dados do nível da água do rio Negro, coletados no porto de Manaus foram utilizados para o desenvolvimento da metodologia. São propostos valores da cota do rio Negro para limitar os quatro períodos hidrológicos (enchente, cheia, vazante e seca) e definir a intensidade da cheia e da seca. O número de dias de cada um dos períodos hidrológicos foi obtido e foi estimada a duração para períodos considerados típicos, longos e curtos. Considerando que modificações abióticas e bióticas do meio estão relacionadas com as mudanças no nível da água, a identificação e a padronização da nomenclatura dos períodos hidrológicos mostraram-se extremamente úteis para uma primeira análise de informações biológicas dos organismos da várzea

    Reproduction and early life history of Hoplias malabaricus in Central Amazon

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    Hoplias malabaricus is a predator fish widely distributed in South America. It is found frequently in the Amazon but its biology in the region is relatively unknown. We present here a description of its reproduction and early life history in a floodplain lakes of Rio Solimões. The fecundity of H. malabaricus is relatively low and increases with fish size. The mean diameter of ripe ovocytes are 1.5 mm. Egg masses were found in the edges of the floodplain littoral. The larvae hatched with 4.7 mm of length and details of its larval development is here presented.Hoplias malabaricus, ou traíra é um peixe predador com ampla distribuição na América do Sul.E encontrado com frequência na Amazônia, porém sua biologia ainda é pouco estudada na região. Nesta nota apresentamos dados relativos a sua reprodução e ao início do seu desenvolvimento larval na várzea do rio Solimões. A traíra se reproduz durante todo o ano. As fêmeas têm fecundidade relativamente baixa, que varia conforme o tamanho do peixe. Os ovócitos maduros são grandes (média = 1,5 mm). Ovos fecundados foram encontrados em posturas nas margens dos lagos de várzea. As larvas eclodiram com 4,7 cm de comprimento e detalhes sobre seu desenvolvimento embrionário são apresentados

    Dynamic population from triportheus albus, t. angulatus and t. auritus (characiformes: Characidae) in amazonian central lakes

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    In the Amazon the fishing is considered an important source of income and animal protein for the people in the region. Among the different fish species that landed in the market and fairs stand out Triportheus albus, T. angulatus and T. auritus. Considering the reduction of some fish stocks in the region, both the quantity and the size of some species, the research proposes to determine the growth parameters, mortality and length-weight relation of these species in floodplain lakes, Manacapuru, AM. The parameters were estimated by analyzing the length frequency distribution with the help of the routine "scan of values of k" method ELEFAN I program FISAT II. The values for each species were: T. albus L∞=24.68cm, k=0.86/year, Ø '= 2.71, A0.95=3.48years, Mp=1.76/year, Mt=0.85/year, Pt=0.0398*Cp2.6303; T. angulatus L∞=26.78cm, k=0.77/year, Ø '= 2.74, A0.95=3.89years, Mp=1.60/year, Mt=0.76/year, Pt=0.0294*Cp2.8599 and T. auritus L∞=27.83cm, k=0.65/year, Ø '= 2.70, A0.95=4.68years, Mp=1.40/year, Mt=0.63/year and Pt=0.0542*Cp2.5094. These species showed rapid growth, high mortality, low life expectancy and short life cycle. It is suggested the parameters population should be continuously monitored to be used as a tool in the stock analysis

    Tambaqui, Colossoma macropomum, fisheries with focus on an area on middle Amazon River, Amazonas state, Brazil

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    This study evaluates the importance of tambaqui (Colossoma macropomum) in fisheries of the Orinoco and Amazon River basins, through the analysis of published data and new data from the fishing fleet of Tefé, a city in the middle Solimões River. Data were collected between 1991 and 1995 in Tefe\'s market and between 1994 and 1995 on board commercial fishing boats. The relative importance of this species can reach 21% of catches in some landing places of the Orinoco basin, in Venezuela; around 8% in the Peruvian Amazonia; and 35% in Bolivian Amazonia. In Brazil, catches of tambaqui increased in the Madeira River region from 10% in 1977 to 32% between 1984 and 1989. In Manaus, this species composed up to 40% of the landed fish in the past. In the 80\'s and 90\'s, the proportion of tambaqui in landed fish has suffered a drastic reduction, declining to as little as 2,5%. In the middle Solimões, which is the main area of fisheries for this species, catches are made with various fishing gears and in different habitats, accordingly with water level fluctuations. In this region, tambaqui fisheries concentrate inside lakes, where the main gears used are gillnet and purse seine, and the catch is composed of the young fish (<55 cm). The habitats created by river bank collapse enseada-pausada") are important for the catch of larger individuals.Este trabalho avalia a importância da pesca do tambaqui (Colossoma macropomum) nas bacias dos rios Amazonas e Orinoco e, mais especificamente, na região do médio Solimões. As análises foram baseadas em dados de literatura e da pesca praticada pela frota de Tefé no médio Solimões, coletados no mercado de Tefé, entre 1991 e 1995, e a bordo de embarcações da frota pesqueira comercial, entre 1994 e 1995. A importância relativa da espécie pode alcançar 21% da produção de pescado em alguns centros urbanos da bacia do Orinoco, na Venezuela; 8% da Amazônia peruana; e 35% da Amazônia boliviana. No Brasil, na região do rio Madeira, a importância relativa do tambaqui subiu de 10% em 1977 para 32% entre 1984 e 1989. Em Manaus, a espécie já respondeu por 44% do pescado desembarcado. Porém, a proporção de tambaqui desembarcado nesta cidade sofreu uma grande diminuição nos anos 80 e 90, chegando a representar apenas 2,5% do total desembarcado. No médio Solimões, região apontada como a principal área de pesca para esta espécie, são utilizados diversos tipos de aparelhos e explorados diferentes habitats, de acordo com a flutuação do nível da água dos rios. A pesca do tambaqui nesta região é realizada principalmente em lagos, através de malhadeira e rede de cerco, incidindo sobre peixes jovens (<55 cm). O ambiente formado pela caída de terras nos meandros do rio enseada-pausada") é importante para a captura de indivíduos de maior porte

    Modelagem do crescimento do tambaqui (Colossoma macropomum Cuvier, 1816): Seleção de modelos e inferência multimodelos

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    The tambaqui, Colossoma macropomum, is one of the most commercially valuable Amazonian fish species, and in the floodplains of the region, they are caught in both rivers and lakes. Most growth studies on this species to date have adjusted only one growth model, the von Bertalanffy, without considering its possible uncertainties. In this study, four different models (von Bertalanffy, Logistic, Gompertz and the general model of Schnüte-Richards) were adjusted to a data set of fish caught within lakes from the middle Solimões River. These models were adjusted by non-linear equations, using the sample size of each age class as its weight. The adjustment evaluation of each model was based on the Akaike Information Criterion (AIC), the variation of AIC between the models (Δi) and the evidence weights (wi). Both the Logistic (Δi = 0.0) and Gompertz (Δi = 1.12) models were supported by the data, but neither of them was clearly superior (wi, respectively 52.44 and 29.95%). Thus, we propose the use of an averaged-model to estimate the asymptotic length (L∞). The averaged-model, based on Logistic and Gompertz models, resulted in an estimate of L∞=90.36, indicating that the tambaqui would take approximately 25 years to reach average size

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Táticas reprodutivas de Characiformes em ambientes de várzea na Amazônia Central

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