P3.21 Sunday, Jan. 6 Group Size Dependent Cohesion of Zebrafish (Danio rerio) in the Presence of Disturbances PRICE, BC*; SHELTON, DS; MARTINS, EP; North Carolina State University; Indiana University-Bloomington; Indiana University-Bloomington firstname.lastname@example.org
Group cohesion may vary because of different social structures (e.g., dominance hierarchies), responses to environmental factors (e.g., physical barriers, turbulence), or due to the immediate perception of risk (e.g., antipredator vigilance following a disturbance). Here, we tested the relative importance of these three features by measuring the distance between individual zebrafish (Danio rerio) in different group sizes, after varying the water current velocities, and manipulating time since disturbance. Across all conditions, we found that groups of four fish were significantly more dispersed than groups of eight fish. These results suggest that social context has a largest and most consistent impact on the spacing of group members. Water flow rates and time after a disruptive event had an important, but less consistent influence on group cohesion. The specific social dynamics that modulate group cohesion in zebrafish, such as spatial alignment, group centrality, aggression, and activity levels are discussed. An investigation of these group and individual characteristics may lead to a better understanding of the behavioral mechanisms that modulate group size dependent spatial distribution of zebrafish.