Influence of intra- and interspecific interactions on thermal tolerance limits

M1 internship: Influence of intra- and interspecific interactions on thermal tolerance limits
Stage de M1: Influence des interactions intra- et interspécifiques sur les limites de tolérance thermique

One internship position focusing on the thermal tolerance limits of freshwater fishes is available at the RECOVER laboratory in Aix-En-Provence (France). The student will work under the supervision of Arnaud SENTIS and Marie LEVET and in collaboration with other people involved in the ERC – CountDown project.

Topic
Climate change is causing more frequent extreme thermal events, bringing species closer to their thermal limits. Ectothermic animals, like fish, are particularly vulnerable to sudden changes in water temperature because their body temperature closely tracks the environment. To better understand their thermal tolerance, the critical thermal method (CTM) is commonly used; it measures both lower (CTmin) and upper thermal limits (CTmax) to predict species’ responses to extreme heat events. These measurements are essential for establishing species’ thermal thresholds and, in turn, defining species’ resilience to rapid warming. While understanding how species respond to thermal stress is crucial, it’s equally important to consider how species interactions within communities might influence these responses.

Intra- and interspecific interactions are common within an ecosystem, and the effects of climate change on a species or community mainly depend on how these interactions change in strength and nature. Evidence indicates that species interactions can influence physiological processes such as growth, reproduction, and metabolic rate. However, research is limited on how these interactions influence individual thermal tolerance as CTmax tests are typically performed on single individuals without considering intra- and interspecific interactions.

Objective
The aim of the internship is (1) to determine thermal limits of different ectothermic species and (2) to understand how intra- and interspecific interactions influence on individual thermal tolerance

Methods and data

As an intern, you will be based at INRAE Aix-en-Provence but are expected to participate in a two-week field trip, located 3 hours away from Lyon, during which you will help collect freshwater species (fish and macroinvertebrates),use different fishing methods, assist with experimental work and data collection. You are also expected to support preliminary analyses and reporting.

Key-words: climate change, thermal tolerance, freshwater species, thermal ecology

Candidate competences:
We are seeking a highly motivated master student with good organisational skills and a strong interest in thermal ecology. Master’s students in biology, ecophysiology, ecology or a related field are welcome.

To apply please send your CV and motivation letter (1 page maximum in French or English) to Arnaud Sentis (arnaud.sentis@inrae.fr) and Marie Levet (marie.levet@inrae.fr). Informal enquiries are welcome – please contact us by email in French or English.

Practical information:
Application deadline: April 1st, 2026
Starting date: June, 1st, 2026
Duration: 2 months
Main advisors: Arnaud Sentis and Marie Levet
Location: INRAE, 3275 route Cézanne, 13182 Aix-en-Provence, France