Mechanisms of trace metal accumulation in the polychaete<i>Neanthes arenaceodentata</i>

Abstract

The mechanisms of accumulation of zinc and cadmium by the marine polychaetous annelid Neanthes arenaceodentata (Moore) have been studied. Animals have been exposed to EDTA chelate buffered sea water containing 65 Zn and 109 Cd. The calculated free ion activities of the zinc and cadmium in the sea water were 10 -8.13 M and 10 -7.65 M, respectively. Uptake occurs from the free ionic pool of metal and EDTA and EDTAmetal complexes are largely excluded from the animal. In unfed animals, the metals accumulate linearly with time at a rate which decreases when the temperature is reduced but increases in the presence of metabolic inhibitors. Experiments using [ 14 C]EDTA as an extracellular marker indicate that the observed increase in accumulation caused by the inhibitors is at least partially due to media entering extracellular anatomical compartments such as the coelom and lumen of the gut which are normally isolated from the seawater by cilia or sphincters.