Effects of terbuthylazine-desethyl, a terbuthylazine degradation product, on red swamp crayfish (Procambarus clarkii).

Terbuthylazine is a widely used triazine pesticide. This, together with one of its degradation products, terbuthylazine-desethyl (TD), are frequently found in quantities exceeding the EU limit of 0.1μg/L in aquatic ecosystems where they might constitute a serious risk to non-target organisms. The sub-chronic effects of TD at 2.9μg/L (real environmental concentration) and at 580μg/L were investigated in a non-target aquatic species, the red swamp crayfish (Procambarus clarkii). Gill and hepatopancreas histopathology, alterations in biochemical parameters of haemolymph, oxidative damage to hepatopancreas, and changes in antioxidant biomarkers in muscle and hepatopancreas were recorded at both tested concentrations after 14days exposure. A 14day recovery period in TD-free water was not sufficient for restoration of normal parameters. Chronic terbuthylazine-desethyl exposure affected biochemical profile, and the antioxidant system, caused oxidative stress and histopathological changes in hepatopancreas of red swamp crayfish.