Assessment of median lethal concentration (CL50) of pollutants on Macrobrachium tenellum juveniles
ABSTRACT Due to the presence of pollutants in aquatic systems, this research aims to analyze toxicity levels of Faena Clásico®, Asuntol®, sodium hypochlorite and diesel on Macrobrachium tenellum juveniles. For the purpose of this study, specimens from 2 to 4 cm in length were used. For glyphosate, hypochlorite and coumaphos bio-assays, a total of 8 individuals were placed per experimental unit, however, only 5 individuals were placed for diesel. Dead individuals were counted at the end of 24 h of exposure. All bioassays were performed in quintuplicate plus a negative control. The mean lethal concentration (LC50) was calculated by a Probit analysis and standard error. The mean lethal concentrations obtained are given at 6 h of exposure for 16 mL L−1 of diesel aqueous extract; and 24 h of exposure, solutions of Asuntol® 6 mg L−1, Classic Faena® 32 mg L−1 and sodium hypochlorite 59 mg L−1. Results show that the different chemicals assessed generate harmful damage to M. tenellum, since agrochemical compounds can cause alterations in the composition of ecosystems, reducing biodiversity in a temporarily or permanently manner.