Master 2 Internship Project at the CRIOBE, UPVD
Jr. Prof. Dr. Claudia Pogoreutz
Dr. Léo Duperret
Dr. Taissa Damasceno
SymbioSwap: Understanding the impact of algal symbionts exchange in adaptation to tropicalization in the Mediterranean Sea.
We are looking for two Master students (Master 2 level) in our project ‘SymbioSwap’ financed by the Pure Ocean Fund and the Fondation UPVD.
Duration: 5-6 months each (January 2027 – July 2027)
https://www.pure-ocean.org/nos-projets/symbioswap/
Background
The poleward migration of marine species is a major manifestation of global environmental change. This shift into ecologically naïve environments can favor invasive dynamics, particularly in the absence of adapted predators or competitors. The Mediterranean Sea is a prime example of this phenomenon, with the invasion of tropical species such as the jellyfish Cassiopea andromeda, the rabbitfish Siganus luridus, and the lionfish Pterois miles. Although the French coast remains less affected than the eastern basin, the Mediterranean is one of the marine regions most impacted by the invasion of non-indigenous species, driven by the combined effects of maritime shipping, aquaculture, and sea surface warming (+0.4°C per decade since 1980). The Suez Canal is one of the main introduction routes from tropical regions. This « tropicalization » of the Mediterranean is ambivalent: (i) it creates a favorable environment for warm-adapted species, while (ii) posing a major threat to this vulnerable ecosystem, which is characterized by a high level of endemism, rich biodiversity, but also sensitivity to warming.
In this context, the SymbioSwap project aims to study the response of photosymbiotic cnidarians to these thermal fluctuations. SymbioSwap harnesses photosymbiotic sea anemone models: like reef-building corals, they maintain a symbiosis with photosynthetic microalgae from the family Symbiodiniaceae, which drive symbiotic nutrient cycling in the holobiont. This relationship is sensitive to thermal stress and therefore vulnerable to « bleaching », the functional breakdown of the symbiosis. Bleaching is characterized by the breakdown of symbiotic nutrient exchange between partners, leading to host starvation and, ultimately, death. While most observed during marine heatwaves, bleaching events have also been reported in the Mediterranean Sea following cold spells. To elucidate the molecular mechanisms underlying cold-induced bleaching, the team led by Dr. Claudia Pogoreutz (Junior Professor Chair, CRIOBE – UPVD) recently showed that exposing the Mediterranean sea anemone Sea Aiptasia couchii to a simulated cold spell causes bleaching through the collapse of photosynthesis in the algal symbionts. This collapse of photosynthesis was accompanied by a profound metabolic reorganization in the host, suggesting host starvation. Consequently, thermal thresholds arising from functional traits of algal symbionts are likely a key factor for the resilience of symbiotic cnidarians in the face of increasing thermal pressure.
SymbioSwap’s main objective is to determine the extent to which symbiotic plasticity can contribute to the rapid adaptation of marine organisms to accelerating climate change. For this, we will assess whether (i) symbiotic sea anemones from the Red Sea (Exaiptasia diaphana) can adapt to the colder conditions of the Mediterranean winter by acquiring Mediterranean algal symbionts; and (ii) whether the sea anemone from the Mediterranean Sea Aiptasia couchii, can adapt to global warming by acquiring tropical algal symbionts.
Approach
Symbiotic and aposymbiotic (i.e., algae-free) sea anemones of both species and isolates of algal symbionts are available or are currently being isolated. Using these tractable biological resources, we will perform a ‘SymbioSwap’, i.e. generate anemones hosting heterologous symbionts from the opposite climatic environment: A. couchii housing Red Sea symbionts, and E. diaphana housing mediterranean symbionts. Following infection, we will subject the heterologous host-symbiont combinations to thermal stress experiments and compare their performance through traditional (photo)physiological and molecular assessments.
This project will help address a major open question in evolutionary ecology and global change biology: the plasticity of cnidarian host-symbiont associations to adapt to a rapidly shifting planet. The results will provide predictive insights into the adaptive capacity of cnidarians in the face of Mediterranean tropicalization, and a foundational understanding of the ecophysiological limits of potential species invasions.
Team:
Principal Investigator: ANR Junior Professor Chair Dr. Claudia Pogoreutz, CRIOBE, Université de Perpignan Via Domitia (UPVD), France
Co-Investigators:
Dr Léo Duperret, CRIOBE, UPVD, France
Dr. Taissa Damasceno, CRIOBE, UPVD, France
Dr. Nils Rädecker, Helmholtz Institute for Functional Marine Biodiversity, Germany
Dr. Christine Ferrier-Pagès, Centre Scientifique de Monaco, Monaco
Interested? Please send a) your CV, b) a letter of recommendation from your previous internships, and c) a letter of motivation explaining why you are interested in this position, and how you would approach the project to:
claudia.pogoreutz@univ-perp.fr
leo.duperret@univ-perp.fr
taissa.lopes-damasceno@uni-perp.fr
Deadline: 23 September 2026
Further reading:
– Baker (2001) Nature, 411:765-766. https://doi.org/10.1038/35081151
– Bianchi & Morri (2003). Biogeographia, 24:1. https://doi.org/10.21426/B6110129
– Cunning et al. (2015). Proceedings Roy Soc B: Biol Sci, 282: 20141725.
https://doi.org/10.1098/rspb.2014.1725
– Cunning et al. (2018). Coral Reefs, 37:145-152. https://doi.org/10.1007/s00338-017-1640-3
– González-Duarte (2016) The Cnidaria: Past, Present and Future.
https://link.springer.com/chapter/10.1007/978-3-319-31305-4_10
– Marangoni et al. (2021). J Exp Biol, 224:3, https://doi.org/10.1242/jeb.235275
– Rädecker et al. (2018). Front Phys, 9:214. https://doi.org/10.3389/fphys.2018.00214
– Rädecker et al. (2021) Proc Nat Acad Sci, 118:e2022653118. https://doi.org/10.1073/pnas.2022653118
– Legain et al. (2026) BioRxiv, https://doi.org/10.64898/2026.03.04.709358
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