THE ACCUMULATION OF DISSOLVED ZINC BY THE SHORE CRAB CARCINUS-MAENAS (L)

The uptake and accumulation of zinc by the shore crab Carcinus maenas have been studied in different dissolved Zn concentrations. Carcinus maenas accumulated about 2, 10 and 200% of its initial load of Zn on exposure to 23, 100 and 3162 mu g l(-1) radioactively labelled Zn respectively for 21 days. No significant Zn excretion was observed in crabs exposed to 100 mu g Zn l(-1) suggesting that C. maenas normally maintains a relatively unchanged body Zn content by maintaining a low Zn uptake rate, rather than a high Zn turnover rate. Zn excretion did occur when crabs were exposed to the environmentally high concentration of 3162 mu g Zn l(-1). The exoskeleton was found to be an important storage site for Zn absorbed from solution.