Excretion of lead, zinc and calcium by the earthworm Dendrobaen a rubida living in soil contaminated with zinc and lead

Abstract

Higher concentrations and total amounts of Pb were found in faeces than urine and mucus or coelomic fluid. The highest concentration of Zn was present in coelomic fluid but the highest total amount of Zn was in earthworm faeces. Metal analysis of the contents of various sections of the alimentary tract showed the highest concentration and total amount of Pb in the contents of the posterior alimentary tract. Zn and Ca showed the opposite distribution and the highest concentrations were found in anterior gut contents while the highest total amounts of Zn and Ca were found in posterior gut contents. The results are discussed in relation to dry weight of material, excretory sites and the presence of water soluble salts. The terminal segments of D. rubida were analysed for Pb and Zn and it was concluded that self-amputation or autotomy of these segments is probably not involved in the elimination of these metals.