ABSTRACT The objective of this study was to compare the histopathological aspects of the liver of free-living and farmed bullfrogs (Lithobates catesbeianus). Thirty liver samples were collected from young and adult bullfrogs in the states of Minas Gerais and Rio de Janeiro, Brazil. Marked blood congestion and even hemorrhage and a large number of melanomacrophages were observed in most of the livers from free-living bullfrogs. Additionally, hepatocytes showed cytoplasmic eosinophilia and some showed nuclear hypertrophy and presence of microvesicular steatosis; small foci of infiltrates of mononuclear cells were observed in some samples, as well as a thicker capsule. In the farmed bullfrogs, cytoplasmic rarefaction was normal. Morphologically, unlike the livers of animals reared on farms, the livers of free-living animals did not show any evidence of protein-mineral deficiency, characterized by cytoplasmic vacuolation and a larger number of melanomacrophages, suggesting greater aggression to the liver parenchyma, probably due to environmental toxicity. Free-living bullfrogs feed on proteins of better biological value, derived from animals preyed in the natural environment.

Resumo: Avaliou-se a concentração de metais pesados (selênio, zinco, ferro, cobre, molibdênio, níquel, cromo, arsênio, cádmio, chumbo e alumínio) no sangue de filhotes de arara-azul (Anodorhynchus hyacinthinus) capturados no Pantanal (n=26) no ano de 2012, partindo da hipótese de que estas aves apresentem níveis desses metais pesados no organismo e que os mesmos tenham relação com o sucesso de eclosão, peso e idade dos filhotes. As amostras de sangue foram digeridas em ácido nítrico e ácido clorídrico e a quantificação dos metais foi realizada por ICP-OES (Espectroscopia e Emissão Óptica por Plasma Indutivamente Acoplado). As amostras de sangue de filhotes de A.hyacinthinusapresentaram concentrações de Cr (0,10μg/g), Fe (3,06μg/g), Al (3,46μg/g), Cd (0,25μg/g), Cu (0,74μg/g), Mo (0,33μg/g), Ni (0,61μg/g), Se (0,98μg/g) e Zn (2,08μg/g). Os níveis de metais pesados encontrados não apresentaram relação com o peso, idade ou sucesso de eclosão.

Abstract: The concentration of heavy metals (Cr, Fe, Al, As, Cd, Cu, Pb, Mo, Ni, Se and Zn) was evaluated in the blood of nestling blue macaws (Anodorhynchus hyacinthinus) captured in the Pantanal, Mato Grosso do Sul (n=26) in 2012; this was based on the hypothesis that these birds exhibit levels of these heavy metals in their organism and that these interfere in hatching success, weight and age of the chicks. Blood samples were digested with nitric acid and hydrochloric acid and the quantification of metals was performed by ICP-OES (Optical Emission Spectroscopy and Inductively Coupled Plasma). Blood samples of nestlings showed concentrations of Cr (0.10μg/g) Fe (3.06μg/g) Al (3.46μg/g), Cd (0.25μg/g) Cu (0.74μg/g), Mo (0.33μg/g), Ni (0.61μg/g), Se (0.98μg/g), and Zn (2.08μg/g). The levels of heavy metals found were not associated with weight, age and hatching success of the chicks.