PDF(Pubmed)
Abstract：
Antarctic krill (Euphausia superba, hereafter krill) is a pelagic living crustacean and a key species in the Southern Ocean ecosystem. Krill builds up a huge biomass and its synchronized behavioral patterns, such as diel vertical migration (DVM), substantially impact ecosystem structure and carbon sequestration. However, the mechanistic basis of krill DVM is unknown and previous studies of krill behavior in the laboratory were challenged by complex behavior and large variability. Using a new experimental set-up, we recorded the swimming activity of individual wild-caught krill under light-dark cycles. Krill individuals exhibited differential phototactic responses to the light regime provided. However, using a new activity metric, we showed for the first time a consistent nocturnal increase in krill swimming activity in a controlled environment. Krill swimming activity in the new set-up was strongly synchronized with the light-dark cycle, similar to the diel vertical migration pattern of krill in the field when the krill were sampled for the experiment, demonstrated by hydroacoustic recordings. The new set-up presents a promising tool for investigating the mechanisms underlying krill behavioral patterns, which will increase our understanding of ecological interactions, the spatial distribution of populations, and their effects on biogeochemical cycles in the future.
摘要：
南极磷虾(Euphausiasuperba，此后的磷虾）是中上层生活甲壳类动物，也是南大洋生态系统中的关键物种。磷虾建立了巨大的生物量及其同步的行为模式，例如Diel垂直迁移(DVM)，对生态系统结构和碳封存产生重大影响。然而,磷虾DVM的机理基础是未知的，并且先前在实验室中对磷虾行为的研究受到复杂行为和大变异性的挑战。使用新的实验设置，我们记录了单个野生磷虾在明暗周期下的游泳活动。磷虾个体对所提供的光状态表现出不同的趋光反应。然而,使用新的活动度量，我们首次显示了在受控环境中磷虾游泳活动的夜间持续增加。新设置中的磷虾游泳活动与明暗循环强烈同步，类似于对磷虾进行实验采样时，磷虾在田间的diel垂直迁移模式，通过水声记录证明。新的设置为研究磷虾行为模式的潜在机制提供了一个有前途的工具，这将增加我们对生态相互作用的理解，人口的空间分布，以及它们对未来生物地球化学循环的影响。
