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| Registros recuperados: 235 | |
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| TRIVINHO-STRIXINO,S.; CORREIA,L. C. S.; SONODA,K.. |
| Infernão Lake, located within the Jataí Ecological Station in Luiz Antônio Municipal district (São Paulo State, Brazil), is one of the most typical ox-bow lake of the Mogi-Guaçu River, and it presents, as the main feature, its great quantity of aquatic macrophytes, whose intensive development, in the last years practically covered the whole mirror of water. With the purpose to point out the composition and to establish the relative participation of the phytophilic zoocoenosis that inhabits the different macrophytes of that lake, a collection program of the main vegetation stands was established. The collections, were carried out randomly, during dry season (1994), in stands of Salvinia auriculata, Utricularia sp., Cabomba piauhyensis, Eichhornia azurea and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chironomidae (Diptera); Aquatic macroinvertebrates; Aquatic phytofauna. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000300018 |
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| VON ZUBEN,C. J.; STANGENHAUS,G.; GODOY,W. A. C.. |
| Em insetos que se utilizam de substratos discretos e efêmeros para a alimentação e postura de ovos, o resultado da competição larval por alimento depende da quantidade de recursos e da distribuição espacial dos imaturos nos substratos alimentares. No presente estudo, os resultados da competição larval por alimento em Chrysomya megacephala, em caracteres como peso de fêmeas, fecundidade e investimento reprodutivo, foram diferentes em situações em que o nível de agregação larval (proporção de competidores por quantidade de alimento) é o mesmo, mas com densidades de competidores e quantidades de alimento proporcionalmente diferentes. Esses resultados indicam que a competição larval pode depender tanto da densidade larval como da quantidade de alimento, em... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chrysomya megacephala; Fecundidade; Peso de fêmeas; Agregação larval; Investimento reprodutivo. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000200002 |
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| ARAÚJO,F. G.. |
| Uma adaptação do Índice de Integridade Biótica (IIB) utilizando a comunidade de peixes foi realizada para um dos trechos mais críticos do Rio Paraíba do Sul, entre Barra Mansa e Barra do Piraí, visando à obtenção de um padrão de monitoramento biológico que permitisse inferir a qualidade da água de maneira segura, robusta e independente de variações a curto prazo. Um programa de amostragens mensais padronizadas foi realizado, entre março de 1995 e fevereiro de 1996, em quatro locais de coletas (Barra Mansa, Volta Redonda, Pinheiral e Barra do Piraí), todos situados junto à embocadura de riachos tributários, onde foram realizadas as pescarias sistematizadas com idêntico esforço, utilizando rede picaré, tarrafas e peneiras. O Índice de Integridade Biótica... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rio Paraíba do Sul; Integridade biótica; Peixes; Poluição. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081998000400002 |
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| RAGUSA-NETTO,J.. |
| I studied the existence of sentinels in Saltator atricollis in a 'campo-cerrado' (Brazilian savanna) during the breeding seasons of 1994-95 and 1995-96. Groups of this species consisted of two to seven birds (N = 25). Sentinels were present (mean ± sd) 62% ± 9% of the time, and most sentinel bouts lasted from less than one to six minutes (although in some occasions for more than 30 min.). Overlap of two or more sentinels occurred on average only 3.2% of the time with birds on guard. Sentinels commonly gave contact calls in the beginning and/or at the end of a sentinel bout. The group size had no effect on time with sentinels. However the encounter rate between raptors and groups significantly influenced the time guarded. The results of this study suggests... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Emberizidae; Brazilian savanna; Raptors; Alertness; Sentinels. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082001000200015 |
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| HATANO,F. H.; VRCIBRADIC,D.; GALDINO,C. A. B.; CUNHA-BARROS,M.; ROCHA,C. F. D.; VAN SLUYS,M.. |
| We analyzed the thermal ecology and activity patterns of the lizard community from the Restinga of Jurubatiba, Rio de Janeiro, Brazil. The broadest activity was that of Tropidurus torquatus, a sit-and-wait forager, while the active foraging teiid Cnemidophorus littoralis had the shortest activity. The nocturnal gekkonid Hemidactylus mabouia was found active during the day only during early morning and late afternoon, when environmental temperatures are low. Body temperature was highest for Cnemidophorus littoralis and lowest for the two Mabuya species. The patterns found here are discussed and compared to those of congeneric species in other habitats in Brazil. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thermal ecology; Lizard community; Activity patterns; Restinga habitat. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082001000200011 |
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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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| RODRÍGUEZ,M. P.; MATSUMURA-TUNDISI,T.. |
| Rotifers are the predominant group of zooplankton found in the majority of reservoirs, constituting more than 60% of the total zooplankton present. Being opportunistic organisms, they easily adapt to changes in environmental conditions, and it is therefore difficult to establish a constant level of composition and occurrence of a species in specific areas at specific times. In order to establish how changes in composition and predominance of a species occurs within a dynamic system, the daily variation in the total density of rotifers and that of the dominant species were studied at short intervals during a period of 20 days at Lobo (Broa) reservoir. Filinia pejleri and Keratella americana were the predominant species, making up 64.3% of the total... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Density; Composition; Dominance; Rotifers; Reservoir. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000100002 |
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| SILVA-NETO,I. D. da. |
| The research on ciliates, flagelates and opalinates have been widespread by the utilization of techniques employing silver impregnation (Protargol), modified by several authors. However, these are time consuming and its results are variable. The present work is a variant of the technique described by Tuffrau (1964, 1967) showing some adaptations made in our laboratory. The organisms can be preserved by different fixatives (alcoholic Bouin, Stieve's fluid, 2.5% glutaraldehyde and others) and then rinsed in destilled water followed by a fast clarification by 3% sodium hypochloride. If the organism is very sensitive to hypochloride, 4% sodium lauryl sulfate may be used and then washed 3 times in distilled water. The protista can be adhered to the glass slides... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Impregnation of protists; Protargol; Technique improvement. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000300010 |
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| BAIDER,C.; TABARELLI,M.; MANTOVANI,W.. |
| Durante a regeneração da floresta tropical, após perturbações naturais ou antrópicas, o banco de sementes do solo está envolvido no estabelecimento de grupos ecológicos e na restauração da riqueza de espécies lenhosas. Para a análise da composição de espécies do banco de sementes de um trecho de floresta Atlântica madura, no Sudeste do Brasil, foram coletadas 57 amostras de solo, distribuídas aleatoriamente em 2 ha, totalizando 28.500 cm³ de solo coletado. Durante um período de 17 meses germinaram 497 sementes, 65% distribuídas entre 0 e 2,5 cm de profundidade, totalizando 872 sementes/m². O banco de sementes dessa floresta caracterizou-se pela presença de dois componentes: o herbáceo, composto por 66 morfotipos,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Banco de sementes; Espécies pioneiras; Floresta Atlântica; Melastomataceae; Regeneração. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000200014 |
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| MEDRI,V.; PEREIRA,G. V.; LEONHARDT,J. H.. |
| Two hundred and forty 45-day-old fingerlings of Nile tilapia (Oreochromis niloticus), sexually reverted with an initial average weight of 1.25 ± 0.14 g, distributed in a totally casualized delineation, during 330 days. The effect of the substitution of 10%, 20% and 30% of the ration by distillery yeast (Saccharomiyces cerevisae) in balanced experimental rations on the development in the breeding of tilapias did not show a harmful effect up to the maximum tested level of 30%, showing that the choice of the yeast in the ration for these fishes depends on the availability and occasional cost. The yeast provides fish with good resistance to unfavorable environmental conditions, which could be verified since there were no statistical differences among the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Yeast; Oreochromis niloticus; Ration; Tilapia. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000100014 |
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| Registros recuperados: 235 | |
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