EAGER: Natural Chromogenic Behaviors of Squid in Oceanic Waters

EAGER：鱿鱼在海洋水域中的自然显色行为

• 批准号: 1420693
• 负责人: William Gilly
• 金额: $ 24.95万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1420693&HistoricalAwards=false
• 关键词: EAGER; Natural; Chromogenic; Behaviors; Squid

Complex color-changing (chromogenic) behaviors in squid provide camouflage by mimicking benthic features such as rocks, coral or algae, and also serve in intra-specific signaling. However, few studies have been carried out under natural lighting conditions in the field, or without the presence of human observers or noisy remotely operated vehicles. This project will extend field studies of natural chromogenic behaviors to the family Ommastrephidae as exemplified by Dosidicus gigas (Humboldt squid). To accomplish the research under natural lighting conditions, the project will develop an improved low-light Crittercam and an improved Driftcam that can operate effectively at greater depths. These improved video platforms will lead to new understanding of the generation and regulation of camouflage and communication in the open-ocean environment. Little is known of predatory behavior in midwater region occupied by Humboldt squid, which in the eastern Pacific Ocean is associated with a vast volume of water that is naturally hypoxic called the oxygen minimum zone (OMZ). This OMZ is currently expanding and moving toward the surface, largely due to climate change. Observations of predatory activity in the upper OMZ will increase our understanding of how pelagic ecosystems might change as climate change progresses, and how these changes could impact economically and ecologically important species like the Humboldt squid.Chromogenic behavior in squid and other cephalopods is generated by muscular organs called chromatophores that are controlled by neural activity in the brain, and this direct, descending motor-control for chromatophores is unique to cephalopods. Pilot studies with the National Geographic Remote Imaging (NGRI) "Crittercam" video-package deployed on free-swimming Humboldt under natural lighting have revealed static patterning-type displays, like those seen in loliginid species, as well as a unique "flashing" behavior, with the entire body rapidly alternating between pale white and deep red. Flashing appeared to occur only during interactions with conspecifics, strongly suggesting a communication role. These data also revealed a more subtle wave-like "flickering" of chromatophores that may emulate fluctuations of light in the water column and provide dynamic countershading or crypsis. Neither type of behavior has been described in the scientific literature. The generation and control of the flashing and flickering chromatophore signals is therefore of great interest. This project will increase our knowledge of chromatophore signals through in situ video observations and anatomic analyses of Humboldt squid that include electrophysiology assessments, and immunohistochemical analyses of mantle tissue. An improved version of an autonomous low-light drift-camera package ("Driftcam") that can operate at midwater depths to observe natural behaviors of Humboldt squid that are too small to carry a Crittercam will be developed during the course of the project. Stanford graduate and undergraduate students will benefit from direct involvement in all of the research activities, and the researchers will also participate in wider public science dissemination efforts through regional K-12 programs, international educational outreach programs, and collaboration with major public media outlets.

鱿鱼复杂的变色（显色）行为通过模仿岩石、珊瑚或藻类等底栖生物的特征提供伪装，并在种内信号传递中发挥作用。 然而，很少有研究已经在野外自然照明条件下进行，或没有人类观察员或嘈杂的遥控车辆的存在。该项目将把自然显色行为的实地研究扩展到以Dosidicus gigas（洪堡鱿鱼）为例的Ommastrephidae家族。 为了在自然光照条件下完成研究，该项目将开发一种改进的低光Crittercam和一种改进的Driftcam，可以在更大的深度有效地工作。 这些改进的视频平台将导致对开放海洋环境中伪装和通信的生成和调节的新理解。 很少有人知道的捕食行为在中层水域的洪堡鱿鱼，这在东太平洋是与一个巨大的体积的水，自然是缺氧称为氧气最小区（OMZ）。这个OMZ目前正在扩大并向地表移动，主要是由于气候变化。 对OMZ上游捕食活动的观察将增加我们对远洋生态系统如何随着气候变化而变化的理解，以及这些变化如何影响经济和生态上重要的物种，如洪堡鱿鱼。鱿鱼和其他头足类动物的显色行为是由称为色素细胞的肌肉器官产生的，这些器官由大脑中的神经活动控制，色素细胞的下行运动控制是头足类动物所独有的。国家地理远程成像（NGRI）“Crittercam”视频包部署在自由游泳洪堡在自然光照下的试点研究揭示了静态图案型显示，像那些在loliginid物种，以及一个独特的“闪烁”的行为，与整个身体之间迅速交替苍白白色和深红色。闪光似乎只发生在与同种的相互作用，强烈建议沟通的作用。这些数据还揭示了一个更微妙的波浪状的“闪烁”的色素细胞，可能会模仿光线在水柱中的波动，并提供动态的反阴影或隐藏。这两种行为都没有在科学文献中描述过。 因此，产生和控制的闪烁和闪烁的色素信号是非常感兴趣的。 该项目将通过对洪堡鱿鱼的原位视频观察和解剖分析，包括电生理学评估和外套膜组织的免疫组织化学分析，增加我们对色素细胞信号的了解。在该项目期间，将开发一个改进型的自动低光漂移照相机包（“Driftcam”），它可以在中层水深处工作，观察因太小而无法携带Crittercam的洪堡鱿鱼的自然行为。 斯坦福大学的研究生和本科生将直接参与所有的研究活动，研究人员还将通过地区K-12计划，国际教育推广计划以及与主要公共媒体的合作，参与更广泛的公共科学传播工作。