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Difficulties in relating Cd concentrations in the predatory insect Chaoborus to those of its prey in nature

Canadian Journal of Fisheries and Aquatic Sciences

By:
, , and
DOI: 10.1139/f03-068

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Abstract

Because Chaoborus larvae take up most of their cadmium (Cd) from food, we tested the hypothesis that Cd concentrations in this insect are directly related to those in their planktonic prey. We measured Cd in Chaoborus and in Zooplankton collected from 24 eastern Canadian lakes varying widely in their Cd concentrations. Cd concentrations in the predator were not correlated with those in bulk zooplankton, whether separated into size fractions liable to be eaten by Chaoborus or not. In highly acidic lakes, Cd concentrations in Chaoborus did not respond to increases in zooplankton Cd because of either competition between H and Cd ions at Cd absorption sites in the predator's gut or differences in prey community composition between highly acidic and circumneutral lakes. Relationships between Cd in Chaoborus and in its potential prey were stronger when we used Cd concentrations for specific crustacean taxa in a mechanistic model. We conclude that predictive relationships between metal concentrations in predators and their prey are likely to be strongest if the subset of prey consumed by the predator has been characterized and if this information is used in a bioaccumulation model.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Difficulties in relating Cd concentrations in the predatory insect Chaoborus to those of its prey in nature
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/f03-068
Volume
60
Issue:
7
Year Published:
2003
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Canadian Journal of Fisheries and Aquatic Sciences
First page:
800
Last page:
808