AMEX - Adaptations to Extreme Environments

The deep ocean is the largest environment on earth, and remains widely unexplored. Yet it is urgent to improve our knowledge on deep-sea habitats, which are threatened by future industrial exploitation of mineral resources, particularly in the case of deep-sea hydrothermal ecosystems. Our group studies responses of metazoans in the face of environmental perturbations (I) such as experienced at hydrothermal vent habitats (temperature, pressure, chemistry), and also the diversity and plasticity of chemosynthetic symbioses (II). The study of these dynamical phenomena requires observations and experiments on live animals, under controlled conditions, therefore justifying another direction of research : the design of pressurised equipments (III) (isobaric sampling cells and pressurised mesocosms).

I - Responses of metazoans in the face of environmental perturbations

- pressure : homeoviscous (lipid analyses) response following acclimation to changing depth

- temperature : response to heat stress (transcription and biochemical analyses) upon contact with the "hotspot" of the hydrothermal vent habitat.

- chemistry : study of olfaction properties with respect to chemical signals in the hydrothermal vent fluids / ecotoxicology studies in response to future industrial exploitation of mineral resources at deep-sea vent environments.

II - Diversity and plasticity of chemosynthetic symbioses

- symbioses in Arthropods (alvinocaridid shrimp), and molluscs (bivalves, gastropods ...) : structural, phylogenetical, and metagenomic analyses

III - Design of pressurised equipments

- Deep-sea organisms are impacted upon exposure to atmospheric pressure. The pressurised aquaria IPOCAMP, BALIST, and AbyssBox, and the isobaric sampling cell PERISCOP, allow to restore hydrostatic pressures prevailing at depth (down to 3000m for these instruments). Therefore they allow sampling and study of animals in a good physiological state.