Offre de stage M1

 INTERNSHIP PROPOSAL
2 months from APRIL 2026
Master 1 level
Uncovering social secrets: exploring the dynamics within social systems in annelids
HOST INSTITUTION
Laboratoire d’Éthologie Expérimentale et Comparée (LEEC)
Université́ Sorbonne Paris Nord (USPN)
SUPERVISOR(S)
• Dr. Louise Peckre (louise.peckre@univ-paris13.fr) LEEC, USPN
• Dr. Lluís Socias Martínez (lluissociasm@gmail.com) Institut de Systématique, Évolution,
Biodiversité (ISYEB), UMR 7205, CNRS/Muséum national d’Histoire naturelle (MNHN) & UFR
918 Terre Environnement Biodiversité (TEB), Sorbonne Université
• Pr. Cristina Lorenzi (lorenzi@univ-paris13.fr) LEEC, USPN
CONTEXT
The study of social behavior has traditionally focused on easily observable metrics, such as group size. However, this approach often oversimplifies the intricate interactions that define social dynamics among individuals. To overcome this limitation, contemporary studies have suggested alternatives, like assessing the 'number of diaerentiated relationships' to explore diaerent levels of sociality, particularly at the individual level (Aureli & Schino, 2019; Bergman & Beehner, 2015; Fischer et al., 2017). Moreover, a growing body of research underscores the importance of taking into account the multidimensional aspect of sociality, advocating for investigations across four key dimensions: social organization (including group size and sex ratio), social structure (involving social interactions), mating system (encompassing mating patterns and reproductive skew), and care system (focused on parental and alloparental care) (Hobson et al., 2019; Kappeler, 2019; Peckre et al., 2019). Understanding the interactions among these dimensions is crucial for a comprehensive view of social systems and their evolution (Prox & Farine, 2020; Socias-Martínez & Peckre, 2023). In primate research, sociality is frequently examined at the individual level, but this approach is far less common in the study of invertebrates. Particularly noteworthy are annelid worms, in which the study of social behavior remains largely unexplored despite significant social variation among phylogenetically related species (Picchi & Lorenzi, 2018). Indeed, in these fascinating creatures, social interactions may be richer and more complex than previously understood. By choosing to investigate invertebrates as model organisms, this project aims to manipulate specific social variables and analyze their eaects across multiple replicated populations.
OBJECTIVES
The goal of this project is to characterize the social structure (both at the individual and system level) of experimental populations (with three diaerent group sizes) of Ophryotrocha diadema, a simultaneous hermaphrodite annelid worm species.
The candidate will:
- Analyze videos to identify agonistic and aailiative social interactions (e.g., biting, rubbing) and proximity between identified individuals (the use of an IA tracking software, such as DeepLabCut, is envisaged).
- Analyze the data at the individual level to identify potential relationship patterns.
To apply, please send a short motivation email and your CV to louise.peckre@univ-paris13.fr and lluissociasm@gmail.com)