AMEX - Adaptations to Extreme Environments

General topics

Our group studies Deep sea chemosynthetic environments, such as hydrothermal vents, hydrocarbon seeps. Sunken wood or whale carcasses are also of interest to us. These remote habitats are caracterized by their patchiness, their elevated biomass, and by peculiar physico-chemical environmental conditions. We study the biology of the endemic species inhabiting such environments, with a particular focus on their dominating symbiotic fauna. Several aspects are studied : the host-symbiont relationship, the sensory organs, the response(s) to thermal, chemical and pression variations. Many of these studies involve experiments on live animals, requiring work at in situ pressure in the lab. Therefore we are also implicated in the design and development of pressurised instruments.

Research axis

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.

Latest scientific articles

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2018

Gallery

Retour du PERISCOP sur son ascenseur, remis à bord par l'équipage, mission TRANSECT 2018, Dorsale médio-Atlantique. © Bruce Shillito
Enceinte de récolte sous pression PERISCOP_SHILLITO
Aquarium pressurisé IPOCAMP
Modélisation d'effort imposés sur un projet de récolte  sous pression (PERISCOP) © Louis Amand
Prélèvement crevettes hydrothermales Rimicaris exoculata par 2300 m profondeur
Colonie d'Alvinella pompejana (dorsale Est-Pacifique)
M Zbinden_crevette
Antennes de crevettes au MEB © Magali Zbinden
Rimicaris exoculata maintenues sous pression dans l'aquarium IPOCAMP
Vue de face de la crevette hydrothermale rimicaris exoculata
Face interne de la cavite branchiale de Rimicaris exoculata