ENSAIOS ECOTOXICOLÓGICOS UTILIZANDO PLANÁRIAS (Girardia tigrina) COMO BIOINDICADORES DO EFEITO LETAL E SUBLETAL DE FIPRONIL E CLORPIRIFÓS

Abstract

The significant increase in the world population causes a greater demand for food, consequently. The advance in the Brazilian agricultural activities promotes an increase in new techniques that provide greater productivity and less loss in the production process, meanwhile it may result in a system which is totally dependent on the use of pesticides. Numerous pesticides active ingredients have been reported to target, or have been found in freshwater ecosystems, also meaning that the toxicity of these pesticides may potentially affect the aquatic ecosystem. However, the potential of a pesticide in order to reach water surface, depends, among other factors, on the physical-chemical characteristics of the compound and the intensity and periodicity in which it is applied. Among the insecticides widely used in agricultural production, there are Fipronil and Chlorpyrifos. Relaying this context, planarians present themselves as good candidates for bioindicators of environmental contamination. Therefore, the study aims to address the acute and chronic toxicity of insecticides based on Fipronil and Chlorpyrifos, through ecotoxicological tests to assess locomotion, regeneration and reproduction of the tropical freshwater planaria Girardia tigrina. For the tests carried out with Fipronil, there was no concentration that would cause an acute effect, therefore, the compound caused chronic effects regarding to the delay of locomotion, regeneration and reproduction of planarians.However, it was noticed that Chlorpirifós caused a lethal and sublethal effect (locomotion, regeneration and reproduction) of planarians in environmentally relevant concentrations considered to be much lower than reported in the scientific literature.