From behavioural analyses to models of collective motion in fish schools

Abstract

Fish schooling is a phenomenon of long-lasting interest in ethology and ecology, widely spread across taxa and ecological contexts, and has attracted much interest from statistical physics and theoretical biology as a case of self-organized behaviour. One topic of intense interest is the search of specific behavioural mechanisms at stake at the individual level and from which the school properties emerges. This is fundamental for understanding how selective pressure acting at the individual level promotes adaptive properties of schools and in trying to disambiguate functional properties from non-adaptive epiphenomena. Decades of studies on collective motion by means of individual-based modelling have allowed a qualitative understanding of the self-organization processes leading to collective properties at school level, and provided an insight into the behavioural mechanisms that result in coordinated motion. Here, we emphasize a set of paradigmatic modelling assumptions whose validity remains unclear, both from a behavioural point of view and in terms of quantitative agreement between model outcome and empirical data. We advocate for a specific and biologically oriented re-examination of these assumptions through experimental-based behavioural analysis and modelling.

Gaussian theory for spatially distributed self-propelled particles

“…There are many examples, such as birds flocks [11][12][13][14][15], schools of fishes [16][17][18], herds of animals [19,20], bacteria colonies [21][22][23], clusters of cells [24], and vibrated granular particles [25,26]. One of the fundamental and pioneer works in active matter is the introduction of a dynamical microscopic model, known as Vicsek model, to study the emergence of collective behavior [27].…”

Collective motion in biological systems

“…On the one hand, a large body of work in theoretical biology and statistical physics has been devoted to bridge the gap between individual and collective behaviour. These efforts yield an important collection of models reviewed in [1][2][3] and also in the paper by Lopez et al [4]. The rationale behind these works was to understand the general mechanisms by which local rules lead to large-scale patterns, with the assumption that these mechanisms are rather independent of the detailed nature of the systems' components.…”

“…The parameters are determined using a dedicated inversion procedure and the numerical values of these parameters are kept unchanged in the following steps, yielding, in the end, a model without any free parameters. In their paper, Lopez et al [4] show that this modelling framework can be used to emphasize a set of major and unknown behavioural components that are likely to play a crucial role in schooling. The characterization of interaction rules and behavioural mechanisms underlying collective motion also benefits from the study of mutants or transgenic individuals in which all the behavioural components can be selectively altered and their role in the coordination precisely evaluated.…”

Emergent oscillations assist obstacle negotiation during ant cooperative transport

“…First, the tendencies for global alignment and cohesiveness (1)(2)(3) are often the result of near-neighbor interactions (2,(4)(5)(6)(7). Quantitative variations in these local interactions can lead to qualitatively different global modes of collective motion (8).…”