Preliminary study of the biodisponibility of magnesium and zinc in specimens of "armado" (Pterodoras granulosus), captured in the reservoir of Itaipu

Abstract

The study of the bioavailability of trace elements in fish can contribute to the evaluation of the animal development in healthy aquatic environment conditions. It was proposed to evaluate the concentrations of magnesium and zinc present in different parts of the "armado†(Pterodoras granulosus): filet, "belly" (abdominal musculature), viscera, heart and liver, and if such concentrations vary in so far as the fish grows. For this purpose, 24 animals weighing between 125 g and 1,558 g were selected . The brackets were subjected to digestion with the use of nitro-perchloric solution and diluted with distilled and deionized water. Metal concentrations were determined by Atomic Absorption. Among the analyzed organs, the heart presented bigger levels of magnesium (4.8485 ± 2.2286 mg g^-1) in smaller individuals, decreasing as the fish grow. Bigger concentrations of zinc were observed in the heart (0.0239 ± 0.0098 mg g^-1) and liver (0.0430 ± 0.0130 mg g^-1), also with bigger incidence in the youthful ones. It was noticed that these elements are important in the metabolic process of this fish species during its physical development.