Effects of acute exposure of chlorpyrifos on the survival, morphology and swimming ability of Odontophrynus carvalhoi tadpoles

This study examines the survival, mortality, morphology and swimming ability of tadpoles exposed to the organophosphate chlorpyrifos (nominal concentrations of 10, 100, 200 e 400 μg L-1) for 192 h. Odontophrynus carvalhoi tadpoles were used as a biological model. Our findings include decreased survival rates of tadpoles primarily at the highest pesticide concentration (400 μg L-1) and deformities in the caudal muscles, causing spasms and tremors. Tadpoles exposed to chlorpyrifos (10 μg L-1) had the lowest swimming speed compared with that of the control group. Tadpoles the other concentrations (100, 200 and 400 μg L-1) were not evaluated since none of the survived 192 h exposure in concentrations above 10 μg L-1. These adverse effects indicate that this organophosphate can affect the survival of tadpoles even in small doses, compromising the local population.