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| Registros recuperados: 235 | |
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| HENRY,R.; NUNES,M. A.; MITSUKA,P. M.; LIMA,N. DE; CASANOVA,S. M. C.. |
| Com a finalidade de detectar possíveis variações espacial e temporal na produtividade primária pelo fitoplâncton, um estudo foi efetuado na Represa de Jurumirim (Rio Paranapanema, afluente do Alto Paraná, Brasil) no período de outubro de 1995 a julho de 1996 em três compartimentos, os Braços Paranapanema (três pontos), Taquari (dois pontos) e Ribeirão das Posses (um ponto). O método do C14 foi utilizado para a medição da produção primária e um estudo de parâmetros físicos e químicos correlatos na coluna de água foi feito também. Em novembro de 1995 e janeiro-fevereiro de 1996, o local T2 (região de transição no Braço Taquari) foi o mais produtivo (23,9 e 20,1 mgC.m-2.h-1, respectivamente) e, nos dois outros períodos (abril e julho de 1996), foi o 2º ponto... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Produção primária; Fitoplâncton; Fatores limitantes; Represa tropical. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081998000400005 |
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| MARTINS,M. L.; YOSHITOSHI,E. R.; UMEKITA,H.. |
| The present work studied helminth parasites of "pacu-manteiga", Myleus tiete (Osteichthyes: Characidae) from Volta Grande Reservoir, MG, Brazil. Fishes with 142.6 ± 24.7 g weight and 17.3 ± 1.0 cm total length were collected. Five out six analysed fish (prevalence 83.3%) were parasitized in the intestine with an average of 535.6 ± 334.6 oxyurid nematodes per fish. The helminth was identified as Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae). It differs from I. brasiliensis (Moravec et al., 1992a) by the absence of lateral alae, higher measures of tail and caudal alae of males, esophageal isthmus length, distance of excretory pore from anterior end and spicule length. In addition, eggs were provided by two long filaments in just one pole and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nematoda; Pharyngodonidae; Ichthyouris voltagrandensis n.sp.; Myleus tiete. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082001000200013 |
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| SOARES,M. L. G.. |
| A Lagoa da Tijuca, localizada ao sul da cidade do Rio de Janeiro, possui estreita faixa de manguezal distribuída de forma descontínua ao longo de suas margens. Os bosques de mangue apresentam grande variabilidade estrutural. Nos bosques monoespecíficos de Laguncularia racemosa, com dap médio entre 3,4 e 7,7 cm e altura média entre 4,5 e 7,7 m, há predomínio de indivíduos com menos de 10,0 cm de diâmetro. Nos demais pontos, observamos bosques mistos, mais desenvolvidos, dominados ora por Laguncularia racemosa, ora por Rhizophora mangle (dap médio entre 7,8 e 16,7 cm; altura média entre 6,8 e 16,1 m), ora por Avicennia schaueriana (dap médio de 7,1 cm e altura média de 5,3 m). A variabilidade estrutural observada é forte indício de área alterada. Observações... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Manguezal; Estrutura vegetal; Conservação; Brasil. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000300016 |
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| SOPHIA,M. G.. |
| Pela arrumação de suas folhas as bromeliáceas permitem a retenção de água nos imbricamentos das mesmas, onde é possível o desenvolvimento de uma ficoflórula associada aos fitotelmatas (tanques de bromélias). Nestes ambientes, foram coletadas ao acaso vinte e cinco amostras através do Estado do Rio de Janeiro. Deste total, dezenove continham representantes de desmídias. A flora fitotélmica de desmídias esteve representada por quatorze táxons, tendo sido identificadas dez espécies, três variedades e uma forma taxonômica. Além do predomínio das Zygnemaphyceae, foram também registradas outras cinco classes de algas neste tipo de ambiente: Chlorophyceae, Cyanophyceae, Bacillariophyceae, Xanthophyceae e Dinophyceae. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Algas; Desmídias; Fitotelmo; Sudeste do Brasil. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000100018 |
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| THOMAZ,S. M.; PEREIRA,G.; PAGIORO,T. A.. |
| Four size fractions of the sediment of six environments of the upper Paraná River floodplain were analyzed for carbon, nitrogen, and phosphorus contents and microbial respiration (oxygen consumption). Particle size did not affect nitrogen and phosphorus content or microbial activity, but did affect carbon content (F = 4.274, df = 3; 20, p = 0.020). The carbon concentration of ultra-fine particles was significantly lower than that of other sizes of sediment particles. Microbial respiration values were well predicted by sediment chemical composition, as shown by multiple regression (microbial respiration = -0.39 - 0.210C + 0.108N + 0.796P; F = 7.0495, p = 0.0022). However, phosphorus was the element which best explained the microbial respiration (partial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Microbial respiration; Nutrient cycling; Floodplain; Sediment fractions; Paraná River. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082001000200010 |
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| MARTINS,M. L.; SOUZA,V. N. de; MORAES,J. R. E de; MORAES,F. R de. |
| Piauçus (Leporinus macrocephalus), were raised in 300 m² ponds (density of 10 fish/m²) presenting asphyxia signals and daily mortality of 27 fishes. Specimens with 8-cm total body length, were collected for necropsy. Mucus of body surface and pieces of organs were collected and examined microscopically, in wet mounts, stained or in histological sections. The smears examination showed the presence of several spores in the secondary lamellae of the gill filaments, identified as Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). Histopatological study showed epithelial hyperplasia and fulfilling of the spaces between the secondary lamellae, congestion and teleangiectasia sinusoidal. It was also observed hyperplasia of the goblet cells and several cysts of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myxozoa; Henneguya leporinicola; Leporinus macrocephalus; Histopathology; Description. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000300018 |
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| COELHO,L. H. L.. |
| Mammal activity was monitored by a track-analysis method, in a 180 ha forest fragment. Three 1 km transects, each one with six tracking stations were established: one along a road side and one along a stream bank ("travel lanes") and one in the forest interior. Transects were monitored for six weeks through the months of September, October and beginning of November 1996. The activity of six morph-species of mammals was accessed, providing 251 records. Results of linear and non-linear habitats were compared, to test the "travel lanes" hypothesis, which predicts higher mammal activity in linear habitats. No statistical evidence supporting the hypothesis was found. The roadside transect showed the lowest mammal activity, whereas the stream side transect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mammal activity; Travel lanes; Edge effects; Forest fragment. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000100007 |
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| ESPÍNDOLA,E. L. G.; MATSUMURA-TUNDISI,T.; RIETZLER,A. C.; TUNDISI,J. G.. |
| With the purpose of analyzing the horizontal distribution of the zooplankton community of the Tucuruí Reservoir in the State of Pará, Brazil, collections were made at 16 stations during August 1988. The stations cover the regions called Caraipé (C), Araçagi (B) and Ararão (A), and represent the different compartments of this ecosystem in regard to the morphometry and the presence or absence of "flooded forest". Our findings showed the existence of three compartments with different limnological characteristics determined as a function of the system's morphometry, a factor that may have influenced the horizontal circulation of the reservoir's water and, consequently, led to physical, chemical and biological differences at each of the sampled stations. All... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zooplankton; Horizontal distribution; Spatial heterogeneity; Reservoirs. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000200001 |
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| MAZZONI,R.; FENERICH-VERANI,N.; CARAMASCHI,E. P.. |
| Electrofishing adequacy was tested as a technique to obtain quantitative data of coastal stream fish populations and communities in the Southeast of Brazil. Seven field trips, between July/94 and July/95, were done in 5 localities of the Ubatiba fluvial system (Maricá, RJ). Seventeen species, among the 22 collected, had their numbers estimated through the Zipping method, the model used to test the sampling methodology. At each field trip, three removals with electrofishing were done in each locality and, according to the number of obtained species at each locality/field trip, we analysed 315 cases. Nineteen cases, among 315, showed failure condition. Estimates were significant (p < 0.01) in 96% of the studied cases. Non-significant cases were obtained... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrofishing; Coastal streams; East basin; Brazil. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000200003 |
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| MARTINS,M. L.; FUJIMOTO,R. Y.; ANDRADE,P. M.; TAVARES-DIAS,M.. |
| The present work described helminth parasites of curimbatá, Prochilodus lineatus Valenciennes, 1836 from Volta Grande Reservoir, MG, Brazil. Eighteen fishes with average 46.7 ± 1.1 cm length and 1,674.8 ± 75.6 g weight were collected. Of the analysed fishes, 15 were parasitized with acanthocephalans in the intestine, showing a prevalence of 83.3%. The helminth was identified as Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae). It differs from other species in dimension of characters and morphology. From the original description of N. curemai, it differs from the biggest dimension of testis, elongated cement gland, nucleated lemnisci, eggs size, larger proboscis hooks length in the middle and in the third circle in males and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acanthocephala; Neoechinorhynchus curemai; Prochilodus lineatus; Minas Gerais; Brazil. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000400019 |
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| SOUZA,A. D. G. de; TUNDISI,J. G.. |
| The main subject of the present work was to carry out a hydrochemistry comparative study between two river basins in São Paulo State: the Jacaré-Guaçu Basin (21°37'-22°22'S and 47°43'-48°57'W) and the Jaú Basin (22°09'-22°28'S and 48°16'-48°47'W). Nine sampling points in the Jacaré-Guaçu River and eight in the Jaú River were established. The water sampling was performed once each two months from March/95 to September/95. The following variables were analyzed: temperature (°C), pH, conductivity (muScm--1), dissolved oxygen (mg/L) and ionic water composition. Comparatively the Jaú River showed higher spatial variability, less oxygenated water and higher mineralization, due to high pedological and geological substrate... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: River basin; River chemistry; Land uses. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000400004 |
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| Registros recuperados: 235 | |
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