Metabolic and antioxidant responses in juveniles of Cherax quadricarinatus under acute cadmium stress

The physiological effect of acute cadmium (Cd) stress on juveniles of Cherax quadricarinatus (von Martens, 1868) was evaluated. The LC50 values of Cd at 24, 48, 72, and 96 h were 271.83 (min: 155.45, max: 527.31), 44.80 (min: 25.95, max: 84.84), 16.82 (min: 10.85, max: 27.46), and 8.48 (min: 6.30, max: 11.67) μg l−1, respectively. The intermediate sublethal Cd concentrations produced a significant hyperglycemic response after 24 h up to 96 h of Cd exposure. For whole-body lactate and triglycerides concentrations, no significant changes were detected. According to the oxidative stress' markers that were also evaluated, no significant effects of Cd exposure on superoxide dismutase (SOD) activities in whole-bodies of C. quadricarinatus were found after 24 and 48 hours, but after 72 and 96 hours significant increases appeared in the treatments of 2, 4, 6 μg l−1 Cd. Catalase (CAT) rose sharply in the 4 and 6 μg l−1 groups after 96 h. No significant differences of malondialdehyde (MDA) concentrations in the whole-body of individual C. quadricarinatus were found in this study. The results suggest that juveniles of C. quadricarinatus showed a low tolerance to Cd and should be suggested as a good test-organism for studying Cd toxicity in crustaceans.