A Geometrical Structure for Predator-Avoidance Fish Schooling

Abstract

This paper conducts a numerical study of a geometrical structure called $\epsilon$-school for predator-avoidance fish schools, based on our previous mathematical model. Our results show that during a predator attack, the number of $\epsilon$-school increases from one to a certain value. After the attack, the number of $\epsilon$-school decreases in the first two predator-avoidance patterns, but continues to increase in the third pattern. A constant value for the number of the $\epsilon$-school is observed in the last pattern. These suggests that when the predator is approaching, each individual in the school focuses more on avoiding the predator, rather than on interacting with its schoolmates. Such a trait is in agreement with real-life behavior in the natural ecosystem.