Effects of Cadmium on Oxygen Consumption and Tissue Accumulation in Tiger Shrimp Penaeus monodon Fabricius

抄録

Tiger shrimps (Penaeus monodon) were exposed to various concentrations of cadmium as cadmium chloride (CdCl₂·2½H₂O) for 96 hours. Survival rates and the lethal concentration fifty (LC₅₀) of shrimps with cadmium concentrations of 0.0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/l within 96 hours were 100%, 100%, 100%, 90%, 67%, 17%, 13% and 0%, respectively, and the LC₅₀-96 hours was 2.42 mg/l. Cadmium also reduced rates of oxygen consumption (Mo₂). The rates of oxygen consumption of shrimps reared in seawater for 1 month with cadmium concentrations of 0, 0.1, 0.5 and 1.0 mg/l were 6.21 ± 1.53, 6.92 ± 1.21, 4.87 ± 1.24 and 4.37 ± 1.28 µmol/g/h, respectively. The concentration of cadmium in the reared shrimps was found to be higher in the head region than that found in the body. The concentrations found in both regions increased with the concentration of cadmium. From the results, it is indicated that shrimps did not abruptly die after exposure to cadmium. But the cadmium may accumulate in shrimps and result in changes to their physiology. The changes in the rates of oxygen consumption may reflect the changes in environmental pollution which occur in habitats where shrimps live.