Trace-metal detoxification in the ventral caeca of Orchestia gammarellus (Crustacea : Amphipoda)

The talitrid amphipod crustacean Orchestia gammarellus (Pallas) was collect ed from metal-contaminated (Dulas Bay, Gironde) and control (Millport) site s in the UK and France. Irrespective of site of origin, the amphipods showe d the same physiological mechanism of trace-metal detoxification, involving the ventral caeca. Copper was always present in lysosomal residual bodies in the ventral caeca. Following laboratory exposure to zinc and cadmium, th e lysosomes usually contained both copper and zinc but cadmium was not dete ctable. The lysosomal copper concentration is positively correlated to that of sulphur, while the concentration of lysosomal zinc is related to that o f phosphorus. Results are interpreted in terms of the differential rates of turnover of metallothioneins chelating copper, zinc or cadmium.