The uptake and loss of dissolved cadmium by the stickleback, Gasterosteus aculeatus L.

The whole-body uptake of cadmium by the three-spined stickleback (Gasterosteus aculeatus) has been measured after exposure of fish to 2.5 and 5.0 mg Cd2+/liter hard water and equal amounts of 2.0 mg Cd2+ plus 2 mg Zn2+/liter and 4.0 mg Cd2+ plus 4.0 mg Zn2+/liter hard water, respectively. Fish absorbed and retained cadmium while the uptake and accumulation of zinc was depressed. The loss of absorbed cadmium was quicker in fish previously exposed to cadmium plus zinc solutions used together. This phenomenon is discussed in relation to the ability of fish to excrete absorbed cadmium.