Exposure to different glyphosate formulations on the oxidative and histological status of Rhamdia quelen.

Due to the wide use of glyphosate (GLY) in soybean cultivation, their residues in the environment may affect non-target organisms such as fish, developing toxic effects. Despite GLY being widely used in Brazil, there are few studies comparing the effects of commercial formulations in native freshwater fish species. Silver catfish (Rhamdia quelen) were exposed to three different commercial formulations of GLY 48% (Orium(®), Original(®) and Biocarb(®)) at 0.0, 2.5 and 5.0 mg/L for 96 h. The effects in thiobarbituric acid-reactive substances (TBARS), catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) and histological alterations were analysed in the liver, whereas alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were studied in the plasma. In the liver, TBARS levels increased and CAT decreased in all treatments and herbicides tested in comparison with the control group. The SOD increased at 2.5 mg/L of Orium(®), Original(®) and 5.0 mg/L Orium(®) and Biocarb(®), whereas GST increased at 2.5 mg/L Orium(®) and decreased at 2.5 mg/L Biocarb(®) when compared to the control group. The main histopathological alterations in hepatic tissue were vacuolisation, leucocyte infiltration, degeneration of cytoplasm and melanomacrophage in all GLY treatments. The ALT decreased after exposure to 2.5 mg/L of Biocarb(®) and AST increased at 2.5 mg/L of Orium(®), Original(®) and 5.0 mg/L of Biocarb(®) in comparison with the control group. In summary, the oxidative damage generated by GLY may have caused the increased formation of free radicals that led to the histological alterations observed in hepatocytes.

Acute exposure to the biopesticide azadirachtin affects parameters in the gills of common carp (Cyprinus carpio).

The biopesticide, azadirachtin (Aza) is less hazardous to the environment, but may cause several toxic effects in aquatic organisms. The Cyprinus carpio (n=12, for all concentrations) after 10days of acclimation under controlled conditions, were exposed at 20, 40, and 60µL/L of Aza during 96h. After this period, fish were anesthetized and euthanized then mucus layer and gills collected. In this study, the effects of exposure to different Aza concentrations were analysed through a set of biomarkers: Na(+)/K(+-)ATPase, lipid peroxidation (TBARS), protein carbonyl (PC), superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase (CAT), glutathione peroxidase (GPx), non-protein thiols (NPSH), ascorbic acid (AsA) and histological parameters and, yet, protein and glucose concentration in the surface area of mucous layer. Na(+)K(+-)ATPase was inhibited at 40 and 60µL/L compared to control. TBARS decreased at 40µL/L compared to control. PC, SOD and GST increased at 60µL/L in comparison to control. CAT increased at 20 and 60µL/L, and GPx increased in all Aza concentrations compared to control. NPSH decreased and AsA increased in all concentrations in comparison to control. Histological analyses demonstrated an increase in the intensity of the damage with increasing Aza concentration. Alterations in histological examination were elevation and hypertrophy of the epithelial cells of the secondary filament, hypertrophy and hyperplasia of the mucous and chlorate cells and lamellar aneurism. Glucose and protein concentrations in mucus layer increased at 60µL/L compared to control. In general, we suggest that 60µL/L Aza concentration affected several parameters causing disruptions carp metabolism.

Utilização de índices ecológicos em assembléias de peixes como instrumento de avaliação da degradação ambiental em programas de monitoramento / Utilization of ecological indexes on assemblages of fish as instrument of assessment of the environmental degradation in monitoring programs

Este trabalho utiliza índices ecológicos em taxocenoses de peixes (constância de ocorrência, diversidade de espécies, riqueza, equitabilidade, índice de qualidade integrado (IQ)) como instrumento de avaliação da degradação ambiental. As amostragens foram padronizadas e realizadas sazonalmente durante dois anos, com rede de arrasto do tipo picaré, em onze pontos da bacia hidrográfica do lago Guaíba. Os pontos que apresentaram maior regularidade sazonal nos índices coincidem com locais de melhor qualidade ambiental indicados por outros fatores (frequência de anomalias, DBO5, temperatura, coliformes totais, oxigênio dissolvido). O cálculo do índice de qualidade integrado (IQ), entretanto, foi extremamente influenciado pela abundância e riqueza de espécies, sendo que os locais considerados de melhor qualidade por este índice correspondem aos de pior qualidade ambiental indicados por outros fatores. A análise realizada demonstrou que à medida que a qualidade da água melhora, o Índice de Margalef diminui. Isto demonstra que mesmo havendo uma melhora na qualidade da água, não houve uma melhora da estrutura da comunidade deste local.

Several ecological indexes in taxocenoses of fish (constancy, diversity, richness, evenness, and integrated quality index - IQ) are used as indicators of environmental degradation through the analysis of standardized and seasonal fish samples taken along two years in eleven localities of the Lake Guaíba drainage. Localities that showed regular diversity indexes along two years are coincident with those with better environmental quality indicated by other factors (frequency of abnormalities in fishes, DBO5, temperature, total coliforms, dissolved oxygen). The integrated quality index, however, was mostly influenced by abundance and richness, being the localities indicated as the best quality by this index coincident with those indicated as bad quality by other factors. The accomplished analysis demonstrated that when the measure of water quality gets better, the Margalef Index decreases. This demonstrates that even having an improvement in water quality, there is no improvement of structure of the fish community of this place.

Alterações histopatológicas observadas nas brânquias do lambari Astyanax jacuhiensis (Linnaeus, 1758) (Teleostei: Characidae) sob influência de efluentes petroquímicos / Histopathological alterations in the gills of the lambari - Astyanax jacuhiensis (Linnaeus, 1758) under influence of petroquimical effluents

The integrated System of Treatment of Liquid Effluent, SITEL, has eight tertiary lagoons connected in series, where occurred a natural fish sttlement of several species of the area. Gills of forty five specimens of Astyanax jacuhiensis collected in the tertiary lagoons 1 and 8 and twenty four in the arroio Bom Jardim were analyzed with paraffin routine histological technique and stained with H&E and PAS (periodic Acid of Sciff). Anomalous tissues were observed in all three sites, being more intense in samples from lagoon 1 than from lagoon 8. The anomalies observed in arroio Bom Jardim samples are less tissue, increase in the number of secretory mucous cells, fusion of the secondary branchial lamellae, disarrangement of the epithelial tisue and aneurysms. The fact anomalies at the lagoon 1 are more intense than observed in lagoon 8 suggests there is a reduction in the effect of the eflluent along the tertiary system...