Copper-rich granules in the ventral caeca of talitrid amphipods (Crustacea; amphipoda: Talitridae)

Abstract

Copper-rich granules were discovered in the ventral caeca of talitrid amphipods inhabiting copperpolluted localities. Transmission electron microscopy has revealed the presence of rounded granules containing homogeneous electron-dense material (with no nucleus or core) in the RtF cells of the ventral caeca of Orchestia gammarellus. The granules did not appear membrane bound. X-ray microanalysis revealed strong copper and sulphur peaks with a minor peak for calcium. In all cases the granules occurred in the cytoplasm of the cells and all Cu was clearly localized within the granules. The association of sulphur within the granules is thought to represent an organic detoxification system. Qualitative studies on the loss and induction of the granules are described. Whole body and individual tissue copper concentrations were found to be elevated in amphipods from polluted sites. The role of such a detoxification mechanism in providing metal tolerance in these animals is discussed.