Araujo, Cristiano V. M.
Mendes, Lucas B.
Sanchez, Andre L.
Espindola, Evaldo L. G.
Total Authors: 6
 Univ Coimbra, IMAR Inst Mar, Dept Life Sci, P-3001401 Coimbra - Portugal
 ULEAM, Cent Dept Res, Manta - Ecuador
 Univ Sao Paulo, CRHEA, NEEA, BR-05508 Sao Paulo - Brazil
Total Affiliations: 3
Science of The Total Environment;
JUN 15 2014.
Web of Science Citations:
The present study examines the ability of juvenile Danio rerio to avoid pyrimethanil-contaminated water. An avoidance assay system was used with a contamination gradient formed by seven compartments, through which the fish could move and choose the preferred compartment(s). Additionally, the influence of fish movements in promoting the mixing between compartments and thus disruption of the gradient over time was also examined by testing sodium chloride (NaCl) at sublethal concentrations. Samples with pyrimethanil were obtained from the commercial formulation Mythos (R), which was applied to mesocosm systems. Samples of the pyrimethanil-contaminated mesocosms water were collected and a series of seven concentrations (0.2 to 1.4 mg L-1 plus a control) diluted with reference (uncontaminated) mesocosm water were added to the system to form the gradient. After 4 h exposure, fish avoidance in the three highest pyrimethanil concentrations ranged from 29 to 66%. The 4 h-AC(50) (concentration at which 50% of the fish avoided pyrimethanil after 4 h exposure) was 1.10 (confidence interval: 1.07 to 1.12) mg L-1. However, the avoidance pattern after 12 h was strongly reduced and it was not possible to calculate the AC(50). This is explained by the results of the NaCl experiment, which showed that the movement of fish in the system accelerates the mixing of the solutions between compartments. As pyrimethanil can trigger avoidance response in D. rerio, this fungicide, even at non-lethal concentrations, could be considered an environmental disturber. (C) 2014 Elsevier B.V. All rights reserved. (AU)