Motion cues tune social influence in shoaling fish

Area of Science:

• Animal behavior
• Collective decision-making
• Social influence

Background:

• Social interactions significantly impact individual fitness.
• Understanding how animals process social cues amidst environmental uncertainty is crucial.
• Collective actions are highly context-dependent.

Purpose of the Study:

• To investigate how visual features, specifically movement speed, influence individual directional choices in zebrafish.
• To determine how social influence is modulated by these visual cues.
• To explore the dynamics of collective decision-making in zebrafish when faced with social information and uncertainty.

Main Methods:

• Zebrafish were exposed to virtual fish silhouettes in a maze.
• The relative speed and coherency of silhouette movement (leader/distractor ratio) were manipulated.
• Individual and group directional decisions were recorded and analyzed.

Main Results:

• Zebrafish exhibited a strong optomotor response, following faster-moving virtual leaders regardless of stimulus coherency.
• Directional accuracy improved with faster leaders, independent of group size.
• Without distinct leaders, zebrafish decisions followed a majority rule.
• Recruitment time decreased with increasing group size, but individual decision-making showed a speed-accuracy trade-off.

Conclusions:

• Significant differences in movement speeds among conspecifics can effectively guide collective directional decisions in zebrafish.
• This mechanism provides a rapid and adaptive strategy for evaluating social information under uncertainty.
• Group size impacts recruitment dynamics but not necessarily individual decision accuracy when strong social cues are present.