EGU22-12500, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

 Menthol-induced bleaching as a tool to rear aposymbiotic foraminifera for symbiosis investigations 

Christiane Schmidt1,2, Marleen Stuhr1, Debora Raposo3, Xavier Pochon4, and Simon Davy2
Christiane Schmidt et al.
  • 1ZMT, Centre of Tropical marine Research, Bremen, Germany (
  • 2School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
  • 3MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
  • 4Cawthron Institute, Nelson, New Zealand

Larger benthic foraminifera (LBF) are important carbonate producers in tropical and subtropical settings and play a large role in the carbon cycle. They suffer from bleaching (the expulsion/loss of the photosymbiotic microalgae) under increased sea surface temperature due to climate change. For artificial bleaching experiments, we used the diatom-bearing foraminiferan Amphistegina lobifera, because of its robustness in the laboratory for symbiosis investigations, and also the more sensitive Sorites orbiculus which hosts endosymbiotic dinoflagellates. In order to induce bleaching, the LBF were exposed to menthol at non-lethal concentrations. Additionally, DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) was applied as a photosynthetic inhibitor. After the 6 week experiment, foraminifera were >95% bleached, visible with the flourescence microscope. Survival rate of protists was high, as pseudopodial movement was still visible. The foraminifer in this bleached state was able to move and extend its pseudopodial network. The next step will be to test symbiont-uptake of those bleached foraminifera, and measure survival time and ecophysiological features of re-infected foraminifera.

How to cite: Schmidt, C., Stuhr, M., Raposo, D., Pochon, X., and Davy, S.:  Menthol-induced bleaching as a tool to rear aposymbiotic foraminifera for symbiosis investigations , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12500,, 2022.