RESUMO
The aim of this study was to determine the 96-h LC50 (lethal concentration for 50% of the test population in 96 h of observation) of mercury chloride (HgCl2) and evaluated its absorption in the gills, liver, and muscle of juvenile "curimatã-pacu," Prochilodus argenteus. The fish were exposed for 4 days to different concentrations of HgCl2: 0.000, 0.0375, 00.075, 0.150, 0.225, 0.300, and 0.400 mg L-1 to get the 96-h LC50, and the concentration of Hg in the tissues. The fish were exposed to different levels of HgCl2 (0.000, 0.0375, 00.075, 0.150, 0.225, and 0.300 mg L-1), for 4 and 7 days, when different tissues (gills, liver, and muscle) were sampled. The mercury concentration values obtained were compared between tissues, days, and concentration of mercury in the water. The 96-h LC50 for P. argenteus was 0.339 mg L-1 of HgCl2, within the range found for other neotropical and tropical species, showing a medium sensitivity. The concentration of Hg in the tissues increased from the muscle to the gills and liver, and according to the increasing concentration of HgCl2 in the water. The fish liver is the most suitable tissue for environmental monitoring and for the evaluation of the consumed fished. Despite being the tissue that least accumulated mercury, the muscle must be evaluated because it is the part consumed by the population.
Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Brasil , Cloretos , Cloreto de Mercúrio/toxicidade , Mercúrio/análise , Mercúrio/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Cu, Pb, Cd, Zn, Cr, Hg, and Fe in the liver, spleen and muscle, of the fish Salminus franciscanus, from two sections of Paraopeba River, highly affected by anthropogenic influences, was detected in levels above those recommended for human consumption. Positive correlations between fish size and levels of metals were detected for Cd, Pb, Hg, and Zn. In the livers, areas with lipid accumulation and pigmented macrophages were also observed, as was fibrosis of the spleen in the parenchymal area through the presence of pigmented macrophages. The diameter of vitellogenic follicles was less and the frequency of atresia was higher in fish from section A. Thus, our study showed that beyond the risk to the population that eats S. franciscanus from the Paraopeba River, we should also consider the risk to the conservation of this species, since histopathological changes were detected in target organs and in some reproductive parameters.