Localization of metals in cells of saprophagous soil arthropods (Isopoda, Diplopoda, Collembola)

This review summarizes results on the intracellular distribution of metals in cells of woodlice (Isopoda), millipedes (Diplopoda), and springtails (Collembola), which are three major groups of saprophagous arthropods contributing to the turnover of soil organic matter. Although the impact of metals and also metal pollution has inevitably been shown at levels of higher biological organization than subcellular mechanisms in these animal groups, the aim of this review is to focus exclusively on storage sites and aspects of intracellular metal metabolism. Thus, methodologically, results obtained by microscopical techniques such as histochemistry, X-ray microanalysis, energy filter transmission electron microscopy, or laser microprobe mass spectrometry were given preference. Results from atomic absorption spectrophotometry of cellular fractions were kept to a minimum. In all three taxa, the main intracellular metal storage sites are various types of "granules" which are widely distributed throughout cell types associated with the digestive system.