This tool provides a dose-response (DR) analysis of growth toxicity test data under a Bayesian framework, including an estimation of the x% effective toxicity value, that can be an x% effective rate (ERx), an x% effective concentration (ECx) or any other expression of your choice. For clarity reasons, we will use in the application the abbreviation ERx. Growth measurement might be any quantitative continuous variable describing the growth of organisms (e.g., shoot length and dry weight for plants). This tool makes it possible to analyse one single or multiple data sets and to get various outputs, such as a summary table of ERx estimates. MOSAICgrowth does not expect any input besides growth data sets. All calculations are based on JAGS software and a companion R-package rjags.
More details about the underlying modelling and guidelines for the application can be found in the vignette, tutorial and our video. If you want more information, please read our scientific paper.

One or more datasets have no common time with the others

Check the following inputs!

The MOSAICgrowth application also provides a prediction tool for growth data.
  • This tool allows interactive simulations of a dose-response (DR) model for a fixed exposure duration based on a three-parameters log-logistic function in order to predict what could be observed in growth-type measurements for a new range of concentrations. Such a tool can be helpful in designing future experiments for a given species/compound combination (see vignette for more details).
  • This tool also allows the users to propagate the parameter uncertainty from a previous DR analysis in order to get prediction together with an uncertainty band around the predicted median curve.




Model parameters

Give a single value for each parameter

Results of prediction for growth data

The plot displays the prediction of growth as a function of the chosen concentrations. Median prediction is symbolized by the orange plain line. If parameters are distributed, the uncertainty band is symbolized by the gray zone which is delimited by the 2.5% and 97.5% quantiles in orange dotted lines. The orange fitted curve represents the median of the prediction. When parameters are distributed, the associated dashed orange fitted curves delimit the 95% credible interval (in grey band).


[1] Manar R, Bessi H, Vasseur P (2009). Reproductive effects and bioaccumulation of chlordane in Daphnia magna. Environnemental Toxicology and Chemistry.
[2] Billoir E, Delignette-Muller M-L, Péry A R R, Charles S (2008). A Bayesian Approach to Analyzing Ecotoxicological Data. Environnemental Science and Technology.
[3] Ducrot V et al. (2014). Development and validation of an OECD reproductive toxicity test guideline with the pond snail Lymnaea stagnalis (Mollusca, Gastropoda). Regulatory Toxicology and Pharmacology.
[4] Charles S, Wu D, Ducrot V (2021). How to account for the uncertainty from standard toxicity tests in species sensitivity distributions: An example in non-target plants. PLOS ONE.

Staff and Contributors

Dan Wu, engineer at LBBE
Gauthier Multari, bachelor student at University Lyon 1
Aude Ratier, post-doc at LBBE
Christelle Lopes, Associate Professor at University Lyon 1
Sandrine Charles, Professor at University Lyon 1