Figure 2. Quantities used in the model formulation.

(A) The distance separates the position of the focal fish from its current point of impact on the wall; is the angle between the heading of fish and the angular position of this point of impact with respect to the center of the tank. Neighboring fish is at distance from fish ; is the angle between the angular position of fish with respect to fish and the heading of fish . The relative heading of fish compared to the focal fish is . (B) Illustration of a Voronoi neighborhood. Fish headings are indicated by arrows. The focal fish is under the influence of its five neighbors in the Voronoi tessellation (dotted lines), one of which is near the tank wall.