An original decontamination process developed by the aquatic oligochaete Tubifex tubifex exposed to copper and lead

Abstract

The aquatic oligochaete Tubifex tubifex is known to be very resistant to pollution, however, the way this organism has adapted is poorly understood. T. tubifex was present in our study-site (Reuil sur Marne, Marne, France), a retention basin that receives contaminated runoff water from a vineyard. Field observations showed that a large proportion of the worms had abnormal caudal regions (completely missing or regenerating). After experimental contamination with subacute concentrations of copper and lead, two metals that cause problems in the vineyards, the animals lost their tails. Metal determinations in the anterior and posterior parts of whole T. tubifex from the polluted site and experimentally contaminated worms revealed a higher concentration of metals in the posterior part. These results indicated that T. tubifex may protect itself against the increase of internal concentrations of toxic metals (Cu and Pb) by the autotomy of the caudal region in which the metals had accumulated. The capacity of the worms to regenerate was not impaired, even in contaminated medium. The possibility to use the loss of tail as a biomarker of contamination is discussed.