Functional Diversity and Performance of Ciliated Marine Invertebrate Larvae: Measuring and Modeling Larval Swimming, Feeding and Hydrodynamic Signaling

纤毛海洋无脊椎动物幼虫的功能多样性和性能：幼虫游泳、进食和水动力信号的测量和建模

• 批准号: 1433979
• 负责人: Houshuo Jiang
• 金额: $ 28.26万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1433979&HistoricalAwards=false
• 关键词: Functional; Diversity; Performance; Ciliated; Marine

Many marine organisms, including mussels, oysters, and barnacles, have a planktonic (drifting) larval stage and a sedentary (less mobile) bottom-dwelling adult stage. The adults of these organisms release a large number of larvae into the water column, where the larvae develop and grow and often, disperse long distances before settling and changing into adult forms. Larval survival and transport in the water column and larval ability in finding suitable habitat for settlement shape the abundance and distribution of the adult population. All these factors are significantly influenced by the interactions between individual larva and its surrounding fluid. However, current knowledge of larval-fluid interactions, especially at the individual level, is scarce. This project will carry out state-of-the-art observational and modeling studies of larval-fluid interactions. This project provides hands-on training opportunities for undergraduate students. Findings from this highly interdisciplinary project will be incorporated to inquiry-based undergraduate curriculum material that will be taught and evaluated in classrooms and made publicly available through digital libraries.Interactions between individual larva and its surrounding fluid significantly impact survival and transport in the water column. Examples of these interactions include: 1) generating currents for movement and particle capture, 2) reducing predation risk through minimizing the hydrodynamic signals, and 3) rapidly adjusting swimming patterns in response to fluid movements, such as near-bottom turbulence during settlement. Understanding these key larval-fluid interactions requires observations at fine spatial and temporal scales due to small larval size and rapid viscous decay. Although the overall morphology of larvae is highly diverse there are common shapes shared between taxonomic groups, such as the "armed morphology" of larval molluscs and echinoids whereby larvae use long ciliated extensions for feeding and swimming. It is unclear how morphology influences larval-fluid interactions. This project aims at filling in these knowledge gaps by applying high speed, high resolution micro Particle Image Velocimetry (microPIV) and computational fluid dynamics (CFD) modeling to quantify and mechanistically examine larval-fluid interactions. This project addresses three groups of questions: (1) How do fine-scale larval-fluid interactions differ between ciliated larvae with similar overall morphology? What are the ecological consequences of these differences? (2) How rapidly can larvae vary their influences on surrounding fluid? (3) What are the limitations of microPIV as a way to observe freely swimming larvae at the relevant scale? To address these questions, a series of microPIV observations will be conducted on 3 pairs of related species that have armed larvae. The hypothesis is that despite similarity in overall shape, larval-fluid interactions differ between species and larval performance peaks at ambient condition that the larvae are found. Hypothesis testing will be achieved through comparing the larval-fluid interactions between these studied species through ontogeny and at different temperatures and viscosities. The obtained observational data will be compared against theoretical hydrodynamic models and CFD models to build a mechanistic understanding of how larvae move water around their bodies and the resulting signals.

许多海洋生物，包括贻贝、牡蛎和藤壶，都有一个浮游的（漂流的）幼虫阶段和一个静止的（不太能动的）海底栖息的成年阶段。这些生物的成虫将大量的幼虫释放到水柱中，幼虫在水柱中发育和生长，并且在定居和变成成虫之前通常会分散很远的距离。幼虫在水体中的生存和迁移以及寻找适宜栖息地的能力决定了成虫种群的丰度和分布。所有这些因素都受到幼虫与周围液体相互作用的显著影响。然而，目前关于幼虫-流体相互作用的知识，特别是在个体水平上，是稀缺的。该项目将对幼虫-流体相互作用进行最先进的观察和建模研究。本项目为本科生提供实践训练机会。这个高度跨学科项目的研究结果将被纳入以探究为基础的本科课程材料中，这些材料将在课堂上教授和评估，并通过数字图书馆公开提供。个体幼虫与其周围流体之间的相互作用对其在水柱中的生存和运输有重要影响。这些相互作用的例子包括：1)产生运动和颗粒捕获的电流，2)通过最小化流体动力学信号来降低捕食风险，以及3)根据流体运动快速调整游泳模式，例如沉降过程中近底部的湍流。了解这些关键的幼虫-流体相互作用需要在精细的空间和时间尺度上进行观察，因为幼虫体积小，粘性衰变快。虽然幼虫的整体形态是高度多样化的，但在分类群之间有共同的形状，例如软体动物和棘皮动物的幼虫的“武装形态”，幼虫使用长纤毛的延伸来觅食和游泳。目前尚不清楚形态如何影响幼虫与流体的相互作用。该项目旨在通过应用高速、高分辨率的微粒子图像测速（microPIV）和计算流体动力学（CFD）建模来定量和机械地研究幼虫与流体的相互作用，从而填补这些知识空白。该项目解决了三组问题：(1)具有相似整体形态的纤毛虫幼虫之间的精细尺度幼虫-流体相互作用有何不同？这些差异的生态后果是什么？(2)幼虫对周围液体的影响变化有多快？(3) microPIV作为一种观察相关尺度下自由游动的幼虫的方法有哪些局限性？为了解决这些问题，将对3对有武装幼虫的相关物种进行一系列的微piv观察。假设是，尽管整体形状相似，但不同物种之间的幼虫-液体相互作用不同，幼虫的表现在发现幼虫的环境条件下达到峰值。假设检验将通过比较这些被研究物种之间通过个体发生和在不同温度和粘度下的幼虫-流体相互作用来实现。获得的观测数据将与理论流体动力学模型和CFD模型进行比较，以建立对幼虫如何在其身体周围移动水以及由此产生的信号的机制理解。