Regulation of zinc concentration by Palaemon elegans (Crustacea: Decapoda): zinc flux and effects of temperature, zinc concentration and moulting

Abstract

The shrimp Palaernon elegans regulated body zinc concentrations when exposed to ambient zinc concentrations up to 100 pg Zn I-', regulation apparently being achieved by the rate of zinc loss varying to equal zinc uptake. Flux of zinc through the shrimp (followed using 211-65 as a tracer) increased with temperature and external zinc concentration. The relation between zinc flux and external zinc concentration was linear in dissolved zinc concentrations between 10 and 42.5 pg Zn I-'. Zinc flux did not vary with size (dry weight) of shrimps. Total body zinc consists of a number of component pools ('fast' and 'slow') exchanging at different rates, the pool sizes varying with the rate of zinc flux through the shrimp. The pools are therefore features of rate processes, not discrete physical entities. Moulting increased accumulation of labelled zinc from surrounding seawater.