ENERGY RESERVES AND DISTRIBUTION OF METALS IN POPULATIONS OF THE ISOPOD PORCELLIO-SCABER FROM METAL-CONTAMINATED SITES

1. Environmental pollution is often accompanied by changes in the energy budgets of organisms living in the polluted area. This study investigated whether metal soil pollution affected energy reserves (protein, glycogen and lipid content) and resistance to starvation in isopods (Porcellio scaber), sampled from a reference, mine and smelter area. 2. Mine isopods were in good physiological condition compared to the reference isopods because energy reserves (lipid, glycogen and protein) in the hepatopancreas were not decreased compared to the reference isopods. In the smelter isopods energy reserves were lower, especially in the largest isopods, which contained the highest zinc, copper and cadmium concentrations. 3. Under starvation, isopod survival time was remarkably long for all populations; the last animal, a mine isopod, died after 180 days. Survival time under starvation was not related to metal concentration in the isopods, except for the smelter isopods; in these animals survival time was negatively related to the zinc concentration. 4. The low energy reserves in the smelter isopods did not result in reduced mean survival time under starvation; survival time was actually longer by about 20 days (20%). Smelter isopods appear to have a decreased metabolic rate, probably related to the toxic effects of zinc and cadmium. 5. It is concluded that soil contamination by metals affected the energy budgets of isopods at the smelter site but not at the mine site.