Uptake and surface adsorption of zinc by the freshwater tubificid oligochaete Tubifex tubifex

Abstract 1. Total and adsorption-free Zn accumulation data are presented. 2. An inverse relationship exists between the adsorbed fraction of total body accumulation of Zn and the time of incubation in 1 mg/1 Zn. 3. Adsorption accounts for approx. 86–90% of total Zn accumulation during 5 min incubations over the concentration range 0.01–10.0 mg/1 Zn. 4. The adsorbed component of accumulation is demonstrated ultrastructurally to be the Zn associated with the supracuticular mucoid coat. 5. The mechanism of Zn uptake and the role of the body surface are discussed.