School of Biological Sciences, University of Sydney, 2006 Sydney, Australia. james.herbert-read@sydney
Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):18726-31. doi: 10.1073/pnas.1109355108. Epub 2011 Nov 7.
Collective motion, where large numbers of individuals move synchronously together, is achieved when individuals adopt interaction rules that determine how they respond to their neighbors' movements and positions. These rules determine how group-living animals move, make decisions, and transmit information between individuals. Nonetheless, few studies have explicitly determined these interaction rules in moving groups, and very little is known about the interaction rules of fish. Here, we identify three key rules for the social interactions of mosquitofish (Gambusia holbrooki): (i) Attraction forces are important in maintaining group cohesion, while we find only weak evidence that fish align with their neighbor's orientation; (ii) repulsion is mediated principally by changes in speed; (iii) although the positions and directions of all shoal members are highly correlated, individuals only respond to their single nearest neighbor. The last two of these rules are different from the classical models of collective animal motion, raising new questions about how fish and other animals self-organize on the move.
集体运动是指大量个体同步运动的现象，当个体采用决定其如何响应邻居运动和位置的相互作用规则时，就会实现这种现象。这些规则决定了群居动物如何运动、做出决策以及在个体之间传递信息。尽管如此，很少有研究明确确定了移动群体中的这些相互作用规则，并且对鱼类的相互作用规则知之甚少。在这里，我们确定了三种关于食蚊鱼（Gambusia holbrooki）社会相互作用的关键规则：（i）吸引力在维持群体凝聚力方面很重要，而我们发现只有微弱的证据表明鱼类会与邻居的方向保持一致；（ii）排斥主要通过速度变化来介导；（iii）尽管所有鱼群成员的位置和方向高度相关，但个体仅对其最近的单个邻居做出反应。后两条规则与经典的集体动物运动模型不同，这引发了关于鱼类和其他动物在移动中如何自我组织的新问题。
