Effect of salinity on the uptake of cadmium by the brine shrimp Arternia franciscana

Abstract

The effect of salinity on cadmium uptake by brine shrimp Artemla franciscana was studied in chemically defined saltwater solutions. Shrimp were acclimated to different salinities and exposed to the metal in solutions of differing salinity and composition. Within each acclimation group, the cadnlium uptake decreased with Increasing salin~ty of exposure. Most of this varlation was expla~ned by changes in the activity of the free metal ion. Among the acclimation groups, uptake increased with increasing salinity of acclimation. Most of this variation was explained by changes in the permeability of the shrimp. Uptake was not influenced by changes in the osmolarity or the concentration of any of the major cations in the solution. The integration of both chemlcal and biological effects of changes in salinity explains almost all variation in cadmium uptake by brine shrimp.