Collective phase transitions in confined fish schools

Area of Science:

• Collective behavior dynamics
• Biophysics of animal groups
• Complex systems modeling

Background:

• Schooling fish behavior is typically modeled in unbounded domains, neglecting crucial boundary interactions.
• Existing models overlook how geometric confinement influences collective animal movement patterns.

Purpose of the Study:

• To develop a novel model incorporating geometric confinement effects into schooling fish behavior.
• To investigate emergent collective phases and dynamics induced by domain boundaries.

Main Methods:

• Integration of flow and wall interaction data into existing data-driven behavioral rules.
• Probabilistic description of group dynamics to identify collective states and phase transitions.

Main Results:

• Emergence of new collective phases: 'following the tank wall' and 'double milling'.
• Confinement induces spontaneous, repeated switching between schooling and milling states.
• Identification of bistable collective states and non-intuitive bifurcations driving phase transitions.

Conclusions:

• Collective transitions in fish schools can occur spontaneously without individual-level adjustments.
• Geometric confinement is a key factor in shaping emergent collective patterns.
• Findings offer new avenues for controlling and engineering collective behaviors in biological and synthetic systems.