Cadmium uptake by the crayfish, Orconectes propinquus propinquus (Girard)

Orconectes propinquus was exposed to 10, 100, and 1000 ppb Cd(Cl 2) containing 0.09 μCi/liter 109 Cd(Cl 2) for 1.5, 4.5, 10.5, 22.5, 46.5, 94.5, and 190.5 hours. At 10 ppb, total Cd uptakes between 1.5 and 94.5 hours were not significantly different. By 190.5 hours, the organisms had accumulated a mean concentration of 18.4 ppm Cd, which was significantly higher than the concentrations accumulated at earlier times. At 100 ppb, Cd uptake at 1.5 hours was significantly less ( P < 0.05) than that at 22.5–190.5 hours and uptake at 4.5 hours was significantly less than that at 94.5 and 190.5 hours. Also, uptake at 10.5 hours was significantly less than that at 190.5 hours. Uptakes were not significantly different between 22.5 and 94.5 hours; but were significantly higher than at 1.5 hours and lower than at 190.5 hours. At 1000 ppb, uptake increased with time and was significantly greater ( P < 0.05) at every time interval monitored. By 190.5 hours, the organisms had accumulated a mean Cd concentration of 534.4 ppm. At all time intervals at 1000 ppb, Cd uptake was significantly higher ( P < 0.01) than that at 100 and 10 ppb. Uptakes at 100 and 10 ppb were not significantly different.