The relative importance of food and seawater as sources of copper and zinc to talitrid amphipods (Crustacea; Amphipoda; Talitridae).
Abstract
Orchestia gammarellus and O. mediterranea were shown to accumulate copper and zinc from a range of copper- and zinc-enriched algal food. Accumulation increased with increasing dietary metal concentrations. Laboratory results were extrapolated to the field (in Scotland), in an attempt to compare the relative importance of food and solution as sources of trace metals to the talitrids in relation to their respective position on the shore. It was concluded that, for O. gammarellus, accumulation of copper from food was a more important route than the accumulation of copper from solution. O. mediterranea, however, was unable to satisfy its copper requirements from a food source, but was able to achieve all its copper requirements from solution. Both species had equal rates of zinc accumulation from food. Dietary sources of zinc contributed more to final derived body zinc concentrations in both species than accumulation of zinc directly from sea water. Dietary zinc accumulation rates were enhanced for O. gammarellus from one zinc-polluted location, in contrast to copper accumulation rates which did not differ intraspecifically between localities. This difference may be a consequence of adaptation or tolerance to the higher ambient zinc bioavailabilities at the polluted locations.