title: Analyzing fish movement as a persistent turning walker.
abstract: The trajectories of Kuhlia mugil fish swimming freely in a tank are analyzed in order to develop a model of spontaneous fish movement. The data show that K. mugil displacement is best described by turning speed and its auto-correlation. The continuous-time process governing this new kind of displacement is modelled by a stochastic differential equation of Ornstein-Uhlenbeck family: the persistent turning walker. The associated diffusive dynamics are compared to the standard persistent random walker model and we show that the resulting diffusion coefficient scales non-linearly with linear swimming speed. In order to illustrate how interactions with other fish or the environment can be added to this spontaneous movement model we quantify the effect of tank walls on the turning speed and adequately reproduce the characteristics of the observed fish trajectories.
authors.affiliation: C. R. Cognition Animale, CNRS UMR 5169, Univ. P. Sabatier, Toulouse, France. gautrais@cict.fr
authors.forename: Jacques
authors.initials: J
authors.lastname: Gautrais
authors.forename: Christian
authors.initials: C
authors.lastname: Jost
authors.forename: Marc
authors.initials: M
authors.lastname: Soria
authors.forename: Alexandre
authors.initials: A
authors.lastname: Campo
authors.forename: Sébastien
authors.initials: S
authors.lastname: Motsch
authors.forename: Richard
authors.initials: R
authors.lastname: Fournier
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blanco
authors.forename: Guy
authors.initials: G
authors.lastname: Theraulaz
mesh_terms: D000818:Animals; D003198:Computer Simulation; D008954:Models, Biological; D010473:Perciformes / Q000502:physiology*; D013269:Stochastic Processes; D013550:Swimming / Q000502:physiology*; D014743:Videotape Recording