Dynamic Similarity or Size Proportionality? Adaptations of a Polar Copepod.

动态相似性还是大小比例？

• 批准号: 0324539
• 负责人: Jeannette Yen
• 金额: $ 5.03万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-15 至 2004-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0324539&HistoricalAwards=false
• 关键词: Dynamic; Similarity; Size; Proportionality; Adaptations

This project explores the feasibility of applying fluid physical analyses to evaluate the importance of viscous forces over compensatory temperature adaptations in a polar copepod. The water of the Southern Ocean is 20 Celsius colder and nearly twice as viscous as subtropical seas, and the increased viscosity has significant implications for swimming zooplankton. In each of these warm and cold aquatic environments have evolved abundant carnivorous copepods in the family Euchaetidae. In this exploratory study, two species from the extremes of the natural temperature range (0 and 23C) will be compared to test two alternate hypotheses concerning how Antarctic plankton adapt to the low temperature-high viscosity realm of the Antarctic and to evaluate the importance of viscous forces in the evolution of plankton. How do stronger viscous forces and lower temperature affect the behavior of the Antarctic species? If the Antarctic congener is dynamically similar to its tropical relative, it will operate at the same Reynolds number (Re) as its tropical congener. Alternatively, if the adaptations of the Antarctic congener are proportional to size, they should occupy a higher Re regime, which suggests that the allometry of various processes is not constrained by having to occupy a transitional fluid regime. The experiments are designed with clearly defined outcomes regarding a number of copepod characteristics, such as swimming speed, propulsive force, and size of the sensory field. These characteristics determine not only how copepods relate to the physical world, but also structure their biological interactions. The results of this study will provide insights on major evolutionary forces affecting plankton and provide a means to evaluate the importance of the fluid physical conditions relative to compensatory measures for temperature. Fluid physical, biomechanical, and neurophysiological techniques have not been previously applied to these polar plankton. However, these approaches, if productive and feasible, will provide ways to explore the sensory ecology of polar plankton and the role of small-scale biological-physical-chemical interactions in a polar environment. Experimental evidence validating the importance of viscous effects will also justify further research using latitudinal comparisons of other congeners along a temperature gradient in the world ocean.

该项目探讨了应用流体物理分析的可行性，以评估粘性力在极地桡足动物的补偿性温度适应中的重要性。南大洋的水温比副热带海洋低20摄氏度，黏度几乎是副热带海洋的两倍，黏度的增加对游动的浮游动物有着重要的影响。在这些温暖和寒冷的水生环境中，都进化出了丰富的拟真足科食肉桡足动物。在这项探索性研究中，将比较来自自然温度范围极端（0℃和23℃）的两个物种，以检验关于南极浮游生物如何适应南极低温-高粘度领域的两个备选假设，并评估粘性力在浮游生物进化中的重要性。更强的粘性力和更低的温度如何影响南极物种的行为？如果南极同系点与其热带同系点在动力上相似，它将以与其热带同系点相同的雷诺数（Re）运行。或者，如果南极同系物的适应与大小成正比，它们应该占据更高的Re状态，这表明各种过程的异速生长不受必须占据过渡流体状态的限制。实验的设计对桡足动物的一些特征有明确的定义，如游泳速度、推进力和感觉场的大小。这些特征不仅决定了桡足类动物与物理世界的关系，还决定了它们之间的生物相互作用。这项研究的结果将提供对影响浮游生物的主要进化力量的见解，并提供一种方法来评估流体物理条件相对于温度补偿措施的重要性。流体物理、生物力学和神经生理学技术以前还没有应用于这些极地浮游生物。然而，这些方法，如果有效和可行，将为探索极地浮游生物的感觉生态学和极地环境中小规模生物-物理-化学相互作用的作用提供途径。实验证据证实了粘性效应的重要性，这也将证明进一步的研究是有道理的，可以利用世界海洋沿温度梯度的其他同系物进行纬度比较。