2024-08-15 04:00:04
LIPhy scientists have demonstrated the existence of a behavioral transition when the environment of zebrafish becomes too crowded, showing how far the collective structure of the school resists the structural complexity of the surrounding environment.
© benfilm.
The study of collective movements allows us to better understand the dynamic structures resulting from the self-organization of groups of individuals.organisation in a school of fish is remarkable because it forms in very varied environments such as the open sea or among corals. The work of research in the field have so far focused on the study of benches in simple environments, free of obstacles. In a recent work, a team from the Interdisciplinary Laboratory of Physics (LiPhy, CNRS / Université Grenoble Alpes) used an approach combining experiments and modeling to study the impact of a complex environment on the collective organization of a school of fish. To do this, the individual trajectories of a small group of zebrafish were recorded in the presence of obstacles whose name and density have been varied.
The school structure of fish was found to be quite resilient to the introduction of obstacles, maintaining an organization similar to that observed in open water. However, when the distance between obstacles becomes sufficiently small, the school structure gradually disappears and fish behave as if they were isolated, aligning themselves with the physical environment and no longer with their conspecifics. The obstacle density at which this transition occurs corresponds to an inter-obstacle distance close to the typical distance between fish in an undisturbed school, i.e. their natural social distance.
Using a statistical model, the ingredients of this behavioral transition, from collective to independent, were analyzed in detail. The physicists show that a structured environment can have a significant influence on fish behavior and that social distance is critical to maintaining collective behavior in a complex environment. These results contribute to the emerging field of active and cognitive matter, and more broadly to the study of animal behavior or swarm robotics through biomimicry. They are published in the journal Physical Review E.
Reference:
Behavioral transition of a fish school in a crowded environment,
Bruno Ventéjou, Iris Magniez-Papillon, Eric Bertin, Philippe Peyla, and Aurélie Dupont,
Physical Review E, published June 11, 2024.
Doi: 10.1103/PhysRevE.109.064403
Open archive: arXiv
1723760108
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