Efeitos do óleo diesel bruto e da sua fração solúvel nos aspectos comportamentais do peixe Poecilia vivipara

Abstract

This study aimed to evaluate the impact of environmental pollution of diesel on behavioral aspects, as well as lethal toxic effects of fish, using the teleost fish Poecilia vivipara as test organism. For this, we used the diesel oil S-50, and the experiments were conducted with raw diesel oil and its water soluble fraction (FSD). Fish were exposed to concentrations of 2.5, 5 and 10% of diesel and FSD in glass aquariums with aeration and room temperature for 96 hours. Ten animals were used per tank in a volume corresponding to a density of 1g / L in triplicate for all treatments and control. The experiment was conducted in a semi-static system, with daily renewal of 20% of water content. ach water exchange, the FSD was renewed, but the diesel fuel, which forms a layer at the air / water interface, was not renewed. During the experimental period, the animals did not receive food and the aquariums were covered with a film sheet of paper. The behavioral changes were monitored for the periods of 2, 24, 48, 72 and 96 h exposure, and each experimental unit (tank) was observed for a total period of 10 minutes to analyze the behavioral patterns of each organism, quantifying the animals thar showed each behavioral change. The results showed that both diesel oil as FSD induced behavioral changes and mortality. With regard to diesel oil, 100% mortality was observed after 72 hours at concentrations of 5 and 10%. At the highest concentration of FSD, mortality reached 50% after 96 h exposure. In this study, the main changes were related to the movement (irritability, lethargy and underactivity), respiratory (hypoxia and erratic swimming near the aquarium surface) and natatory disorders.