The missing biomarker link: Relationships between effects on the cellular energy allocation biomarker of toxicant-stressed Daphnia magna and corresponding population characteristics
De Coen, W.M.; Janssen, C.R. (2003). The missing biomarker link: Relationships between effects on the cellular energy allocation biomarker of toxicant-stressed Daphnia magna and corresponding population characteristics. Environ. Toxicol. Chem. 22(7): 1632-1641. https://dx.doi.org/10.1002/etc.5620220727 In: Environmental Toxicology and Chemistry. Setac Press: New York. ISSN 0730-7268; e-ISSN 1552-8618, more |  |
| Keywords | Agents > Surfactants
Biomarkers
Cadmium chlorides
Contaminants
Metabolism > Energy metabolism
Potassium chloride
Statistical data > Population dynamics > Life tables
Stress (biological)
Arthropoda [WoRMS]; Branchiopoda [WoRMS]; Diplostraca [WoRMS]; Crustacea [WoRMS]; Daphnia magna Straus, 1820 [WoRMS]; Invertebrata
Fresh water |
| Abstract | The cellular energy allocation (CEA) methodology was used to assess the adverse effects of toxic stress on the energy budget of test organisms. This biochemical assay is quantified by determining changes in the available energy reserves, Ea (total carbohydrate, protein, and lipid content) and the energy consumption, Ec (electron transport activity). The CEA methodology was fully explored by using neonates of Daphnia magna exposed for 96 h to six model toxicants (CdCl2, K2Cr2O7. tributyltin chloride, linear alkylbenzene sulfonic acid, sodium pentachlorophenolate, and 2,4-dichlorophenoxyacetic acid). To evaluate the ecological relevance of the CEA parameter, we compared the suborganismal responses with population-level parameters (obtained from 21-d life-table experiments) such as the intrinsic rate of natural increase (rm) and the mean total offspring per female. The observed reductions in CEA values were both the result of a decrease in Ea and an increase in Ec. From all individual CEA components analyzed, the lipid reserve criterion was the most sensitive endpoint studied. Both the CEA-based lowest-observed-adverse-effect concentration (LOAEC) values and the effective concentration of 10% (EC10) values were significantly (p < 0.05) and linearly correlated with the chronic (21-d) LOAEC and EC10 values based on growth, survival, and reproduction. This relationship demonstrates the usefulness of the methodology to predict long-term effects. Furthermore, significant (p < 0.0001) sigmoid relationships between the 96-h CEA value (expressed as percentage relative to the control) and population-level effects were observed. |
|
