DEB-1

Mechanistic effect modelling of the pond snail Lymnaea stagnalis

Elke I. Zimmer, PhD project, 01.04.2010 – 31.05.2013

The research was mainly conducted at the department of Theoretical Biology at the VU university in Amsterdam, The Netherlands. Experiments were conducted at the National Institute of Agronomic Research (INRA) in Rennes, France.

Supervisors: Tjalling Jager, Bas Kooijman (VU)
Co-supervisor:
Virginie Ducrot (INRA)
Associated partners:
CTGB; BASF; HARLAN

In this project, Dynamic Energy Budget (DEB) theory  was used to study the energy metabolism of the pond snail L. stagnalis under control conditions and under toxicant exposure. The pond snail L. stagnalis has been proposed as standard test organism for OECD guidelines for aquatic organisms, and the laboratory conditions are currently under investigation for suitability for standardization.

Questions to be addressed:

  • how suitable is the proposed test protocol for standardization?
  • how can the use of a DEB model to interpret the data improve the understanding of the data?

Approach

DEB theory provides a mechanistic framework to understand the metabolic mechanism of action (mMoA) of a toxicant and its subsequent effects on the life cycle. The application of DEB theory to ecotoxicological problems has become known under the name DEBtox. It also provides the possibility to extrapolate to other temperature and food levels, as well as exposure scenarios, which makes it highly suitable for use in ecological risk assessment. An individual model based on DEB can easily be incorporated in an IBM frame-work and thus provides the possibility to investigate population level effects.

mMoAs_intro

Results

1) Juvenile pond snails are food limited when fed with lettuce, the standard food source for ecotoxicity testing with the pond snails. In life cycle experiments with the pond snail, this food limitation amplifies the toxicity of tested compounds and may lead to a misinterpretation of test results. The results were presented at the 21st SETAC Europe meeting in Milan (slides) and the CREAM midterm workshop (poster), and have been published in:

Zimmer, E.I., Jager, T., Ducrot, V., Lagadic, L., Kooijman, SALM. (2012) Juvenile food limitation in standardized test: a warning to ecotoxicologists. Ecotoxicology, 21(8):2195 -2204

2) In an experiment that was conducted under the standardized conditions mentioned above, we discovered that the sub-lethal effects (a hormetic response in growth and reproduction) could be explained by differences in the food intake. The interactionbetween food and toxicants need to be carefully considered, because it can easily lead to misinterpretation of toxicity. The results have been presented at the 6th SETAC World congress (slides). The manuscript is under review.

3) The pond snail is a simultaneous hermaphrodite, which leads to plasticity in the reproductive investment: depending on mating opportunity, the snail tunes its investment into male / female function.  We studied the interaction of this plasticity with an additional stressor (starvation). The results have been presented at the 3rd international DEB symposium and at the CREAM open conference (slides). The manuscript is under review.

Publications

The thesis entitled The pond snail under stress – Interactive effects of food limitation, toxicants and copulation explained by Dynamic Energy Budget theory can be downloaded here.

  • Martin, B.T., Zimmer, E.I., Jager, T., Grimm, V. (2012) Dynamic Energy Budget Theory meets individual based modeling – a generic and accessible approach. Methods in Ecology and Evolution, 3(2):445 – 449
  • Jager, T., Zimmer, E.I.(2012) Simpli ed dynamic energy budget model for analysing ecotoxicity data. Ecological Modelling, 225:74-81 Z
  • Zimmer, E.I., Jager, T., Ducrot, V., Lagadic, L., Kooijman, S.A.L.M. (2012) Juvenile food limitation in standardized test: a warning to ecotoxicologists. Ecotoxicology, 21(8):2195 – 2204
  • Jager, T. Martin, B.T. and Zimmer, E.I. (2013). DEBkiss or the quest for the simplest generic model of animal life history. Journal of Theoretical Biology, 328:9-18
  • Agatz, A., Cole, T., Preuss, T., Zimmer, E.I., Brown, C. (2013). Feeding inhibition explains eff ects of imidacloprid on the growth, maturation, reproduction and survival of Daphnia magna. Environmental Science and Technology, 47:2909 – 2917
  • Jager, T., Barsi, A., Hamda, N.T., Martin, B.T., Zimmer, E.I. and Ducrot, V. (Acc.). Dynamic energy budgets in population ecotoxicology: applications and outlook. Acc. Ecological Modelling, DOI10.1016/j.ecolmodel.2013.06.024

Contact information: Elke I. Zimmer now works as a Postdoctoral researcher in the unit Biosphere Impact Studies at the Belgian Nuclear Research Center SCK-CEN in Mol, Belgium. She is working on the development of a DEB model for Lemna minor, which will be used to analyze mixtures of compounds. You can reach her via Enable-Javascript@To-Read-E-mail-Address

Last updated 12/02/2014