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Pharmacology, Toxicology and Environmental Health

University of Nebraska - Lincoln

Daphnia magna

Publication Year

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Full-Text Articles in Life Sciences

Environmentally Sensitive Life-Cycle Traits Have Low Elasticity: Implications For Theory And Practice, Valery E. Forbes, Mette Olsen, Annemette Palmqvist, Peter Calow Jan 2010

Environmentally Sensitive Life-Cycle Traits Have Low Elasticity: Implications For Theory And Practice, Valery E. Forbes, Mette Olsen, Annemette Palmqvist, Peter Calow

Valery Forbes Publications

The relationships between population growth rate and the life-cycle traits contributing to it are nonlinear and variable. This has made it difficult for ecologists to consistently predict changes in population dynamics from observations on changes in life-cycle traits. We show that traits having a high sensitivity to chemical toxicants tend to have a low elasticity, meaning that changes in them have a relatively low impact on population growth rate, compared to other life-cycle traits. This makes evolutionary sense in that there should be selection against variability in population growth rate. In particular, we found that fecundity was generally more sensitive …


Mixture Toxicity Of Three Toxicants With Similar And Dissimilar Modes Of Action To Daphnia Magna, Kristian Syberg, Anders Elleby, Henrik Pedersen, Nina Cedergreen, Valery E. Forbes Jan 2008

Mixture Toxicity Of Three Toxicants With Similar And Dissimilar Modes Of Action To Daphnia Magna, Kristian Syberg, Anders Elleby, Henrik Pedersen, Nina Cedergreen, Valery E. Forbes

Valery Forbes Publications

Mixture toxicity of similar- and dissimilar-acting toxicants can be predicted by the models concentration addition (CA) and independent action (IA) using single substance toxicity data. Knowledge of the toxicants mode of action is thus required in order to use the models. In order to test the predictive capability of the models, we conducted Daphnia magna 48 h immobilization experiments with three toxicants with known modes of action (dimethoate, pirimicarb and linear alkyl benzene sulfonate) singly, and in binary and ternary mixtures. Our results indicate that CA and IA predict binary mixtures of similar- and dissimilar-acting toxicants equally well. CA and …