Beyond Fish in Formation: A Two-Tier Approach for Biomechanical Studies of Collective Movement

Area of Science:

• Animal behavior
• Fluid dynamics
• Biomechanics

Background:

• Fish schooling is often viewed as rigid, but real-world observations show frequent positional changes.
• Existing research confirms that fish conserve energy in schools compared to solitary swimming.
• This presents a paradox: how do dynamic interactions within schools lead to energy efficiency?

Purpose of the Study:

• To investigate the relationship between schooling dynamics and energy conservation.
• To test the hypothesis that fish modulate their movement in response to hydrodynamic cues from neighbors.
• To develop a methodology for analyzing kinematic modulation in fish schools.

Main Methods:

• Utilized artificial intelligence-enabled tracking and video processing to quantify individual movement variations within schools.
• Employed a mechanical flapping mechanism and controlled enclosures to isolate and study inter-individual hydrodynamic interactions.
• Assessed fish responses to fluid stimuli from robotic models and other fish.

Main Results:

• Fish within schools demonstrated significantly higher positional and kinematic modulation compared to solitary individuals.
• Fish in controlled environments showed a strong ability to respond to hydrodynamic stimuli from nearby fish or robotic models.
• The study successfully analyzed high-resolution kinematic modulation in schooling fish.

Conclusions:

• Schooling dynamics, characterized by positional and kinematic modulation, are driven by responses to fluid dynamic stimuli.
• This modulation is key to understanding how fish achieve energy savings through collective movement.
• The developed two-tier approach provides a robust framework for future studies on fish schooling behavior and energetics.