556 resultados para Bagre (Peixe)


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Examinou-se o potencial alelopático da planta invasora de pastagem assa-peixe (Vernonia polyanthes), através dos efeitos dos extratos aquosos (concentração de 10%) da parte aérea, de raízes e de sementes sobre a germinação (porcentagem e velocidade) e o alongamento da radícula das gramíneas forrageiras Brachiaria humidicola, Brachiaria decumbens e Brachiaria brizantha cv. Marandu. O pH, a condutividade e o potencial osmótico foram determinados em cada extrato. A contribuição do potencial osmótico foi isolada através de cálculo, tendo por base os potenciais osmóticos dos extratos e da água e a equação de regressão que se ajustou a cada parâmetros, em função da variação do potencial osmótico na faixa de 0,0 a 0,4 MPa. Os bioensaios foram desenvolvidos em câmaras do tipo BOD, com temperatura controlada para 35/15oC (diurna/noturna) e fotoperíodo de 12 horas-luz (bioensaios de germinação), e temperatura constante de 35oC e fotoperíodo de 24 horas-luz (bioensaios de alongamento da radícula). Os resultados indicaram que tanto o pH como a concentração de cátions não contribuíram para os resultados encontrado. O assa-peixe evidenciou potencialidade alelopáticas que variaram em função da espécie receptora e da parte da planta doadora do extrato. A velocidade de germinação foi o indicador mais sensível aos efeitos dos extratos aquosos da assa-peixe.

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O objetivo deste trabalho foi desenvolver um método de análise de resíduos do herbicida fluridone em peixes. O herbicida foi extraído do peixe (partes comestíveis), concentrado em colunas de florisil e então analisado em cromatógrafo líquido com detector de UV visível a 313 nm. Os coeficientes de correlação obtidos para linearidade do detector e do método foram de 0,99983 e 0,99987, respectivamente. Com o método descrito foi possível extrair, separar e identificar com eficiência o herbicida fluridone das amostras de peixe, o qual apresentou médias de percentagens de recuperação variando de 60 a 73%. O limite de detecção foi de 20 mg kg-1.

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Os mecanismos que causam o amolecimento e a perda na textura post-mortem da carne de matrinxã foram determinados por meio das mudanças na microestrutura do músculo, imediatamente após a morte e depois de 12 horas de estocagem a -3°C. As observações na microestrutura, realizadas com microscópio eletrônico de transmissão, foram semelhantes aos resultados obtidos na força de ruptura do músculo medidos com o texturômetro. Os valores da força da ruptura foram menores para a carne após o resfriamento. Observou-se que as fibras do colágeno do tecido conectivo pericelular se desintegraram e que as do colágeno do tecido conectivo do miocommata conservaram sua arquitetura e integridade. Houve pouca degradação da linha Z. Isso sugere que o amolecimento post-mortem da carne de mantrinxã, durante a estocagem a -3°C, é causado pela degradação do tecido conectivo pericelular.

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Amostras de músculo de carpa comum (Cyprinus carpio) e de água de três viveiros fertilizados com dejetos de suínos e de um viveiro em que os peixes foram alimentados com ração comercial para peixes foram analisadas durante seis meses. O objetivo foi observar a presença de bactérias patogênicas, como Salmonella, Staphylococcus aureus e coliformes totais e fecais, em peixes comercializados in natura no município de Chapecó, Santa Catarina. Foram aferidos quinzenalmente, na água dos quatro viveiros, oxigênio dissolvido, pH, turbidez, alcalinidade total, dureza total, amônia, nitrato e ortofosfato, bem como a quantidade de coliformes totais e fecais. A análise microbiológica músculo dos peixes demonstrou ausência de Salmonella em todas as amostras. A contagem dos demais microrganismos manteve-se inferior ao limite máximo permitido pela legislação vigente, em todas as amostras. Portanto, os peixes analisados estavam aptos ao consumo humano, pois atenderam aos padrões recomendados pela Divisão Nacional de Vigilância Sanitária de Alimentos (DINAL). A comparação entre os viveiros fertilizados com dejetos de suínos e o viveiro fertilizado com ração comercial para peixes não apresentou diferença significativa, porém apresentou efeito significativo sobre oxigênio dissolvido, turbidez, alcalinidade total e amônia. A matéria orgânica foi responsável pelos maiores valores, com exceção da turbidez, que foi menor no viveiro fertilizado com ração comercial para peixes. Entretanto, após análise de todos os parâmetros físico-químicos e microbiológicos da água dos viveiros, pode-se constatar que todos os viveiros se enquadraram nas classes II ou III da classificação de águas interiores estabelecida pelo CONAMA.

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Um experimento foi realizado com o objetivo de estimar a concentração espermática das espécies dourado (Salminus brasiliensis), curimba (Prochilodus lineatus), jundiá (Rhamdia quelen), cascudo-preto (Rhinelepis aspera) e tilápia-do-nilo (Oreochromis niloticus) pelo método de espermatócrito. Utilizaram-se 19, 58, 51, 43 e 85 reprodutores de dourado, curimba, jundiá, cascudo-preto e tilápia-do-nilo, respectivamente. Com exceção da tilápia-do-nilo, os reprodutores foram submetidos ao processo de indução hormonal e posteriormente submetidos a coleta de sêmen. Foram comparadas as técnicas de mensuração da concentração espermática do sêmen por contagem em câmara hematimétrica de Neubauer e por espermatócrito. Os resultados obtidos foram submetidos à análise de regressão a 5% de probabilidade. As concentrações espermáticas mensuradas por ambas as técnicas apresentaram relação linear, para curimbas, jundiás e tilápias-do-nilo, com equações y = 6,6624 × 10(9) + 3,68553 × 10(8)x; y = 2,153 × 10(9) + 4,426 × 10(8)x e y = -9,0897 × 10(8) + 6,0167 × 10(8), respectivamente. O método de espermatócrito pode ser utilizado para estimar a concentração espermática do sêmen de curimbas, jundiás e tilápias-do-nilo.

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The objectives of this work were to evaluate three protein sources - soybean meal, fish meal and feather meal - and two methods of calculation of rations - the calculated in terms of crude protein (CP), according to recommendations of NRC (1988); and the proposed by the AFRC (1993), and calculated in terms of metabolizable protein (MP) - through the performance of calves. The animals were confined and submitted to five diets, that varied only protein sources in its composition, thus discriminated: SM- Soybean Meal, FsM- Fish Meal, FeM- Feather Meal, FsMU- Fish Meal and Urea, and FeMU Feather Meal and Urea. A complete diet was supplied, composed of 40% of sorghum silage and 60% of concentrate. All treatments possessed about of 2.56 Mcal/kg DM of metabolizable energy, being the treatments SM, FsM and FeM calculated by the system of CP, with 18% of CP, and the treatments FsMU and FeMU, calculated by the system of MP, with 16.3% of CP and a same amount of metabolizable protein than the treatment SM, with 112.0 grams of MP/day. Individually, the treatments did not present significant differences (P > 0.05) in the final alive weight, in daily gain weight and in dry matter intake, having differences only in the feed:gain ratio. The best feed:gain ratio happened in the treatment FsM and the worst in the treatment FeMU. It is concluded that the MP method provides similar results to the method of CP. The treatments with fish meal provide larger weight gains, smaller intake and better feed:gain ratio than the treatments with feather meal, staying the treatment soybean meal with intermediary daily gain.

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Toxic effects of phytosanitary surfactants for jewel tetra (Hyphessobrycon eques). Surfactants are amphipatic molecules that reduce the surface tension of water and make up the inert components of pesticide formulations. Thus, the objectives of this study were: to estimate the lethal concentration (LC(I)50;96h); classify and evaluate water quality during testing of the following surfactants: Agral[registered trademark], Aterbane[registered trademark]BR, Ag-bem[registered trademark], Energic[registered trademark], Fixade[registered trademark] and Gotafix[registered trademark] for jewel tetra (Hyphessobrycon eques); and the signs of intoxication in the animals. For this, the fish were acclimated for ten days in the bioassay room. The animals were exposed to the surfactants in an entirely randomized design with three replications. The LC(I)(50;96h) of surfactant Agral[registered trademark] was 3.29 mg L-1; Aterbane[registered trademark] BR 8.21 mg L-1; Energic[registered trademark] 2.34 mg L-1; Gotafix[registered trademark] 4.37 mg L-1; Fixade[registered trademark] 3.38 mg L-1; and Ag-bem[registered trademark] 34.95 mg L-1. The variables of water quality were unchanged. The fish showed an increase in the opercular beating after exposure; 4 and 24 hours, loss of gasping ability; 48 hours, slow opercular beating; and 72 and 96 hours later, recovery. The surfactants Energic[registered trademark], Agral[registered trademark], Gotafix[registered trademark], Aterbane[registered trademark] BR and Fixade[registered trademark] can be classified as moderately toxics, and Ag-Bem[registered trademark] as slightly toxic for H. eques; this organism shows similar intoxication signs for all surfactants.

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This paper presents the identification of tectonic deformation through the application of the stream-gradient index (slope x length) method in the Rio do Peixe hydrographic basin, located in western State of Sã o Paulo. The main principle used is that river valleys are the best tools for this type of analysis because of their fast adjustment to even the most gentle crustal deformations. This type of analysis for structural studies is extremely useful in the western region of the State of São Paulo, where deep chemical weathering results in a thick regolith and scarce outcrops. The stream length index is the ratio of the altimetric amplitude of each drainage and the natural logarithm of its length. The value obtained is plotted on maps at the median point of each drainage, allowing the drawings of lines with the same values (isodefs). Three anomalies (A, B and C) were identified along the Rio do Peixe valley representing uplift sectors indicated by the formation and distribution of Upper Quaternary deposits in terraces and modern fluvial plains and alluvial fans. In correlation with known tectonic data for this region it is possible to attribute the A and B anomalies to the Ribeirão Preto and Presidente Prudente crustal sutures, respectively. The smaller C anomaly needs further field investigation, but it could be associated with the Três Lagoas crustal suture. It must be emphasised that these sutures are inherited from the Precambrian Basement which had a strong influence on the Phanerozoic evolution in the whole sedimentary and volcanic stratigraphic pile of the Paraná Basin and on the dominant structural lineaments directions developed therein .The A, Band C anomalies are suggestive of renewed uplift as a result of neotectonic action in modern times.

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This work evaluates the impact of the pink shrimp Farfantepenaeus paulensis (Perez-Farfante, 1967) fishery on fish and crab assemblages of Lagoa do Peixe National Park, Brazil. We observed that composition of catches is similar to shrimp fisheries using fyke-net at others estuaries of Rio Grande do Sul State: pink shrimp (53%), accessory catches (24%) and bycatch (23%). However, fishery composition showed distinct differences along the saline gradient of the main park's lagoon. Regarding only fish species, the most impacted species in this fishery were Brevoortia pectinata (Jenyns, 1842), Micropogonias furnieri (Desmarest, 1823), and Jenynsia multidentata (Jenyns, 1842). In others estuaries from Rio Grande do Sul, in contrast, the most impacted species were M. furnieri, Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). The potential impact of the pink shrimp fishery at Lagoa do Peixe National Park seemed to be weaker when compared to shrimp fisheries elsewhere. We believe that the decision to prohibit this fishery at the Lagoa do Peixe National Park should not be based on its potential damage to the fish and crab assemblages but based on the simple fact that Brazilian laws do not allow fisheries inside National Parks.

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Running water is one of the most important of all the physical processes which fashion the landscape, allowing gravity to operate along the valley floors. Besides this, the streams show a fast adjustment to the crustal deformations, even to the most gentle ones. This geologic behavior turns them a potential tool for neotectonic studies, specially the analysis of morphotnetric parameters associated with hydraulic gradient and discharge, this second factor being directly proportional to the extension of the streams. Both elements, gradient and stream length, can be combined in the SL index. The purpose of this paper is to show the RDE index application in the neotectonics analysis of the Rio do Peixe hydrographic basin and to compare the obtained values with the geologic basement incised by the streams. This basement encompasses Cretaceous sedimentary rocks of post-Serra Oeral Formation magmatism (Caiuá and Bauru groups) and Quaternary deposits that include chiefly recent alluvial plains and some Pleistocene terrace deposits. In the final part of this paper, an attempt is made in order to correlate the RDE results and the neotectonic framework admitted to this portion of the São Paulo State territory, as well as with field geologic, seismologic and paleoseismologic known elements. The results indicate the presence of two groups of anomalies: The first set corresponds to the Marília-Exaporã Plateau border, and the second one, located in the central portion of the hydrographic basin, is correlated to the Presidente Prudente seimogenic zone.

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This work aimed to study the bacterial contamination of the catfishes stings Genidens genidens (Valenciennes, 1839); and Cathorops agassizii (Agassiz, 1829) found in the estuary-bay complex of Santos and São Vicente (São Paulo State). Fish samples for bacteriological analyses were obtained and constituted of a group of 50 specimens, being 25 of Cathorops agassizii and 25 of Genidens genidens,. The bacteriological analyses showed that there was contamination of the stings by 13 different strains of Enterobacteriaceae with Klebsiella pneumoniae (26,80%) as the most frequent bacteria and lower percentual frequencies for Enterobacter sp and Escherichia coli (16,27%) and Serratia marcescens, Serratia sp. and Proteus mirabilis (1,16%). Gram positive bacteria, as well fungi species were not detected in the samples. In basis of the Gram negative species characterized, is possible to consider the bacterial strains are representative of the environmental public health conditions, as well as, accidents with these fish stings are able to develop significative acute secondary infections in humans.

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Haematological investigation is an important part of disease diagnosis. The techniques used for mammals are generally applicable for fishes with slight modification. The presence of nucleated erythrocytes and thrombocytes in fish may cause some confusion in the identification of blood cells, mainly in total leukocytes count. This work evaluated two different methods (direct and indirect) of leukocytes counting. Specimens of tilapia were divided randomly into four groups of 48 fish each. Each group was further randomized into three replicate experiments of 16 fish per replicate in 40 L aquarium and maintained for 10 days. Counting of leukocytes in peripheral blood was determined in six fishes per group at the times: 0, 3, 7 and 10 days. The direct method in Neubauer chamber showed a large dispersion of data in regard to the average, the opposite was observed in indirect method determined in blood smears that showed more homogeneity among groups. Due to this factor the indirect method can be considered more accurate than the direct method for counting leukocytes in fishes.

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The study was carried out to evaluate the inclusion of increasing levels (0, 3,0 and 6.0%) of fish silage (SSFP), in the ration. The parameters studied were urea, uric acid, total protein, triglycerides, total cholesterol and lipoproteins (LDL, HDL and VLDL). Eighteen female piglets Moura weighting and crossbred Duroc x Moura, were used with 24,0± 3,0 kg in average weight and 90 days of age and eighteen male pigs Moura and crossbred Duroc x Moura, with 31,5±5,0 kg in average weight and 70 days of age in a randomized design with 3 treatments. The results showed no effect to the addition up to 6,0% of SSPF in the swine diet neither for in growth, nor to the serum parameters, even if had been found alteratum on the urea plasmatic concentrations experiments. All the parameters was closed to the normal value recommended in the literature.