Shapes of Krill Swarms and Fish Schools Emerge as Aggregation Members Avoid Predators and Access Oxygen
Shapes of Krill Swarms and Fish Schools Emerge as Aggregation Members Avoid Predators and Access Oxygen
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DOI：
10.1016/j.cub.2010.08.041
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发表时间：
2010-10-12
期刊：
影响因子：
9.2
通讯作者：
Cox, Martin J.
中科院分区：
文献类型：
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作者：
Brierley, Andrew S.;Cox, Martin J.
许多类型的动物表现出聚集行为：鸟群，蜜蜂群，鱼群和有蹄类动物群[1]。陆地和空中的聚集可以直接观察到，摄影技术提供了这些环境中动物行为的见解[2]和行为理论可以测试的数据[3]。然而，在水下，有限的能见度会妨碍直接观察，而且对浅滩化的了解仍然不完整。我们使用多波束声纳声学观测南极磷虾浅滩的三维结构[4]。浅滩的大小和堆积密度变化很大，但表面积：体积比（粗糙度）的分布范围很窄，约为3.3 m（-1）[5]。鱼群（例如，沙丁鱼，沙丁鱼）从地理和海洋学上不同的位置有非常相似的粗糙度[6-8]。这种共同的紧急形状属性表明了不同生态系统的共同驱动力。群体行为可能是复杂的[9]，但一个简单的权衡-我们的模型-其中个体鱼和磷虾只有他们进入充满氧气的水和暴露于捕食可以解释观察到的鱼群形状。在全球变暖的海洋中，氧气供应量减少[10]可能会影响浅滩结构：因为结构会影响捕食者和渔民的可捕性[11-13]，出于生态和商业原因，了解这种反应是必要的。
Many types of animals exhibit aggregative behavior: birds flock, bees swarm, fish shoal, and ungulates herd [1]. Terrestrial and aerial aggregations can be observed directly, and photographic techniques have provided insights into the behaviors of animals in these environments [2] and data against which behavioral theory can be tested [3]. Underwater, however, limited visibility can hamper direct observation, and understanding of shoaling remains incomplete. We used multibeam sonar to observe three-dimensional structure of Antarctic krill shoals acoustically [4]. Shoal size and packing density varied greatly, but surface area:volume ratios (roughnesses) were distributed narrowly about similar to 3.3 m(-1) [5]. Shoals of clupeid fish (e.g., sardine, anchovy) from geographically and oceanographically diverse locations have very similar roughnesses [6-8]. This common emergent shape property suggests common driving forces across diverse ecosystems. Group behavior can be complex [9], but a simple tradeoff-that we model-in which individual fish and krill juggle only their access to oxygen-replete water and exposure to predation can explain the observed shoal shape. Decreasing oxygen availability in a warming world ocean [10] may impact shoal structure: because structure affects catchability by predators and fishers [11-13], understanding the response will be necessary for ecological and commercial reasons.