Effect of temperature on the uptake of copper by the brine shrimp, Artemia franciscana

Abstract

The effect of temperature on the uptake of copper by the brine shrimp Artemia franciscana has been studied in chemically defined saltwater solutions. Animals were acclimated to temperatures ranging from 10°C to 35°C and exposed to copper at different temperatures within this range. The results show that within each temperature acclimation group, copper uptake increases with increasing temperature of exposure. Within each temperature acclimation group most of the variation can be related to the combined effect of temperature on the chemical speciation and diffusion rate of copper in the diffusion layer lining the exchange surfaces. The magnitude of the apparent activation energy for copper uptake indicates that it is a facilitated diffusion process. The effect of the temperature of exposure on copper uptake decreases with increasing temperature of acclimation. The temperature acclimation effect is such that, except for the lowest temperature of acclimation, exposure to the temperature of acclimation has no effect on copper uptake. This indicates that temperature acclimation involves physiological alterations that compensate for the effect of an increasing temperature of exposure on the transport of the free cupric ion across the solution-body interface.