Dissipação do Thiamethoxam e sua Influência nos Teores de Fenóis em Hedychium Coronarium

http://dx.doi.org/10.5902/2179460X17302The growth of agriculture over natural environments has led to the exposition of several plant species to pesticides without the due knowledge of their effects on the physiology of these organisms. The objective of this study was to evaluate the effect of different levels of thiamethoxam on the levels of total phenols and on the chromatographic profile of Hedychium coronarium leaves and rhizomes. The plants of H. coronarium were exposed to two concentrations of thiamethoxam in a controlled environment with the application of spraying. The pesticide was detected in leaves during the first 26 days of experiment, but not in rhizomes. The levels of thiamethoxam showed an important reduction in the leaves during the experiment. The levels of total phenols were affected by the presence of thiamethoxam. The similarity in the frequency peaks in the chromatographic profile of the leaves and rhizomes showed the influence of the insecticide, in which this influence in rhizomes was more evident in the concentration of 190 mg L-1.O crescimento da agricultura sobre os ambientes naturais tem levado várias espécies vegetais à exposição aos inseticidas, sem que seu papel na fisiologia destes organismos seja conhecido. O objetivo deste estudo foi avaliar os teores de thiamethoxam e determinar sua influência nos teores de fenóis totais e no perfil cromatográfico das folhas e rizomas de Hedychium coronarium. As plantas de H. coronarium foram expostas a duas concentrações de thiamethoxam em ambiente controlado, com aplicação através de pulverização. O inseticida foi detectado nas folhas durante os 26 dias de experimento, mas não nos rizomas. Os teores de thiamethoxam apresentaram uma redução acentuada nas folhas no decorrer do experimento. Os teores de fenóis totais sofreram influência da presença do thiamethoxam. A similaridade na frequência dos picos no perfil cromatográfico das folhas e rizomas demonstrou a influência do inseticida, onde nos rizomas essa influência ficou mais evidente na concentração de 190 mg L-1.

Avaliação de Metais nos Peixes Astyanax Altiparanae, Leporinus Friderici e Hypostomus Strigaticeps, Coletados no Córrego Curral de Arame, Dourados, MS

O lançamento de metais no ambiente causa uma série de problemas ambientais. Portanto, este estudo tem como objetivo avaliar a concentração dos metais ferro, zinco, cobre, níquel e cromo em Astyanax altiparanae, Leporinus friderici e Hypostomus strigaticeps coletados no córrego Curral de Arame, Dourados, MS. As coletas de peixes foram realizadas durante oito meses em quatro pontos do córrego. As análises de metais foram realizadas empregando absorção atômica. O zinco evidenciou melhor a diferença entre os pontos de coleta. O peixe de fundo apresentou maior concentração de metais em relação às outras espécies. Os resultados apresentados indicam que as amostras de peixes não excederam as concentrações de metais permitidas pela legislação brasileira, mostrando-se que os peixes avaliados são boas fontes dos metais analisados, considerando os valores de ingestão diária recomendada.

Assemblage of fish species associated with aquatic macrophytes in Porto Murtinho Pantanal, Mato Grosso do Sul, Brazil

The Porto Murtinho Pantanal lies at the limit of the Upper Paraguay River basin, and despite its biogeographical importance, several aspects of the ecology of the fish assemblage are not known. Monthly samples of fish associated with aquatic macrophytes were taken from February 2009 through January 2011. A total of 46,327 individuals were collected, belonging to 144 species. Characiformes and Siluriformes were the predominant orders, and Odontostilbe pequira, O. paraguayensis and Bryconamericus exodon were the most abundant species. Two species, Cynopotamus sp. and Pimelodus mysteriosus, were recorded for the first time in the Pantanal, and a new occurrence record of Cichla piquiti was observed, representing an approximately 400 km range expansion in your distribution area in the Pantanal

<b>Influence of environmental integrity on the feeding biology of <i>Astyanax altiparanae</i> (Garutti & Britski, 2000) in the Ivinhema river basin</b> - doi: 10.4025/actascibiolsci.v35i4.19497

This study aimed at analyzing the influence of different levels of environmental integrity of streams of the Ivinhema river basin (Mato Grosso do Sul State, Brazil) on the diet of A. altiparanae. Samplings were performed from July 2001 to November 2011 at 101 sites, using sieves, seining and gill nets, and electrofishing. Streams were classified into three levels of environmental integrity. We analyzed 664 stomachs with the methods of frequency of occurrence and volumetric analysis index, combined in the Importance Index (AI). The species was omnivorous, with predominance of allochthonous resources. At the least impacted sites, the most representative resource was allochthonous plant material; and in the altered sites in the rainy period the most consumed item was allochthonous arthropods. On the other hand, at the most impacted sites in the dry period there was a lower consumption of allochthonous plant material and allochthonous arthropods, compared with other levels of environmental integrity considered, with higher consumption of autochthonous arthropods. The results evidenced that in the least impacted sites there was greater contribution from allochthonous resources, probably because these environments show a more preserved riparian forest

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil. In this paper we investigate how seasonal flooding influences the composition of assemblages of ants foraging on trees in the Pantanal of Mato Grosso do Sul. During the flood in the Pantanal, a large area is covered by floods that are the main forces that regulate the pattern of diversity in these areas. However, the effects of such natural disturbances in the ant communities are poorly known. In this sense, the objective of this study was to evaluate the effect of temporal variation in assemblages of ants foraging on trees in the Pantanal of Miranda. Samples were collected during a year in two adjacent areas, one who suffered flooding during the wet period and another that did not suffer flooding throughout the year. In 10 sites for each evaluated habitat, five pitfall traps were installed at random in trees 25 m apart from each other. In the habitat with flooding, the highest richness was observed during the flooding period, while there was no significant change in richness in the area that does not suffer flooding. The diversity of species between the two evaluated habitats varied significantly during the two seasons. Most ants sampled belong to species that forage and nest in soil. This suggests that during the flood in flooded habitats, ants that did not migrate to higher areas without flooding adopt the strategy to search for resources in the tree canopy