Estudo preliminar da biodisponibilidade de magnésio e zinco em espécimes de armado (Pterodoras granulosus), capturados no reservatório de Itaipu

The study of the bioavailability of trace elements in fish can contribute to the evaluation of the animals 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, if such concentrations vary in so far as the fish grows. For this purpose, we selected 24 animals weighing between 125 g and 1,558 g. The brackets were subjected to digestion with the use of nitro-perchloric solution and diluted with distilled and deionized water. Metals 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 his physical development.