Cadmium resistance in Gammarus pulex (L.).

The ability of Gammarus pulex to develop cadmium resistance through physiological acclimation was investigated. Organisms were found to be significantly more tolerant to acute cadmium toxicity after pre-exposure to sublethal concentrations of cadmium and zinc. The induced elevation in cadmium tolerance was shown to be associated with an increase in the body concentration of a metallothionein-like protein. Pre-exposure had no apparent effect on cadmium uptake, although it did influence the distribution of cadmium within the organisms. Whereas pre-exposure to low levels of zinc and cadmium increased cadmium tolerances in acute tests, it had no observable effects on sublethal responses measured during chronic exposure.