Lethality and Acetylcholinesterase Inhibition in a Native Invertebrate Species Exposed to Water Samples of an Impacted Stream (Reconquista River Basin, Argentina).

The study of multiple biomarkers in bioindicator species is a useful tool to evaluate water quality in addition to physicochemical analysis. The aim of this work was to study the toxicity of water samples from two sites with different anthropogenic impacts (R: near a residential area and FP: close to horticultural farms and industrial waste treatment plants) from Las Catonas sub-basin (Reconquista River basin) in the native gastropod Biomphalaria straminea. Some physicochemical parameters and chlorpyrifos concentration were measured in water samples. Snails were exposed in laboratory conditions 48 h to the water samples and neurotoxicity, behavior, lethality and acetylcholinesterase, carboxylesterase, glutathione S-transferase, glutathione reductase and catalase activities were measured. In water from FP, chlorpyrifos was detected and conductivity and pH were higher than in R. Lethality (60%) and a decrease (30%) in acetylcholinesterase were observed in snails exposed to FP indicating that water contamination causes high toxicity in B. straminea.