<b>Ecotoxicity of glyphosate and aterbane^&reg; br surfactant on guaru (<em>Phalloceros caudimaculatus</em>)</b> - doi: 10.4025/actascibiolsci.v32i3.6795

Abstract

Aquatic macrophytes are important components of aquatic ecosystems, but these plants have become a problem due to their occurrence in different regions. Some studies aimed to demonstrate the effectiveness of herbicides to control these macrophytes; however, few studies report the possible ecotoxicological effects. The objective of this study was to estimate the acute toxicity (LC (I)50;96h) and assess water quality variables for glyphosate in the Rodeo^® formulation, Aterbane^® BR surfactant and mixtures of glyphosate + 0.5% and 1.0% of surfactant, for the guaru fish (Phallocerus caudimaculatus). The guaru was exposed to increasing concentrations of glyphosate and a mixture of glyphosate + 0.5 and 1.0% of surfactant. The mixture of glyphosate and glyphosate + 0.5 and 1.0% of surfactant showed (LC (I)50;96h) > 975.0 mg L^-1. For the surfactant, the rate was 5.81 mg L^-1. The glyphosate and mixtures of glyphosate + 0.5% and 1.0% of surfactant caused a decrease in pH and dissolved oxygen and increased the electrical conductivity of water. Glyphosate in the Rodeo^® formulation and the mixtures with surfactant Aterbane^® BR can be classified as practically nontoxic, whereas surfactant Aterbane^® BR can be considered as moderately toxic to guaru.