Developing a chronic test for field-collected mayflies: The influence of laboratory conditions on development and survival of Cloeon dipterum

Environmental Toxicology and Chemistry, vol. 45, pp. 1871–1879

Abstract

In recent years, the interest has increased for testing nonstandard species in the environmental risk assessment of pesticides. Especially mayflies seem to be of interest, because of their relevance in aquatic ecosystems, their potential sensitivity, and their vulnerability. So far there is a lack of standardized methodologies in acute and chronic testing of mayfly species. While acute testing of field-collected nonstandard species represents few challenges, especially chronic testing needs better and more detailed evaluation regarding the robustness and suitability of testing methods. Therefore, we conducted an inter-laboratory comparison of chronic experimental designs for the mayfly Cloeon dipterum. These methods were established in the two participating laboratories and were tested using a cross-design experiment. The test designs differed mainly in the feeding and light conditions. In addition, the influence of species origin was investigated and the Cloeon Development Index (CDI) was established to allow for a standardized evaluation of mayfly development. Our study showed that experimental design, especially the method of feeding, had a huge impact on larval development, while the origin of the organisms played a minor role. However, it was demonstrated that the mortality rate was higher for larvae that were transported between the participating laboratories than for larvae collected near each testing site. The presented work is not meant to be input for an Organisation for Economic Co-operation and Development test guideline but tries to provide necessary basic information for the performance of robust chronic studies with the mayfly C. dipterum. Based on these results, recommendations can be provided for an experimental design of a chronic test and on validity criteria regarding control survival and development rates for chronic testing of C. dipterum.

Authors 8

1. Silke Claßen
   Affiliation as printed

   Gaiac Eco Assessment GmbH , Aachen,

2. Ivo Roessink corresponding

   Wageningen University & Research

   Affiliation as printed

   Wageningen Environmental Research , Wageningen,

3. Eric Bruns
   Affiliation as printed

   BAYER AG , Monheim am Rhein,

4. Katrin Gergs
   Affiliation as printed

   Gaiac Eco Assessment GmbH , Aachen,

5. André Gergs
   Affiliation as printed

   BAYER AG , Monheim am Rhein,

6. Jutta Hager
   Affiliation as printed

   BAYER AG , Monheim am Rhein,

7. Richard Ottermanns Aachen

   RWTH Aachen University

   Affiliation as printed

   Gaiac Eco Assessment GmbH , Aachen,

   RWTH Aachen University , Aachen,

8. Thomas G Preuss
   Affiliation as printed

   BAYER AG , Monheim am Rhein,