Collaborative Research: Comparative feeding by gelatinous grazers on microbial prey

海洋由微小的植物和动物（微生物）主导，它们处于食物网的基础，并在全球范围内驱动能量和碳循环。被称为胶状食草动物的柔软的水母状动物专门用粘液制成的网捕食微生物。凝胶状食草动物在海洋中非常丰富，对微生物的摄取率很高，因此可能对微生物的丰度和多样性产生非常强烈的影响，并可能改变目前对海洋食物网的理解。然而，胶状食草动物在其分布中非常脆弱和不均匀，因此很难用传统方法在有意义的规模上确定这些重要的捕食者-猎物关系的大小和动态，因此它们通常在食物网研究中被忽视。更多地了解胶状食草动物和微生物之间的捕食者-猎物关系，将提高对海洋结构、力学和动力学的理解。这是地球上重要的经济和生态系统资源。这个项目是确定凝胶动物对微生物的食草率，为食物网模型提供信息。该项目还训练学生沟通、传播和解释科学发现。这些更广泛的影响目标将通过俄勒冈大学（应用科学传播）和波特兰州立大学（高级技术写作）的合作伙伴关系来实现，培训1名博士生，2名本科生和4名科学传播实习生，并开展为期一周的研讨会，建立学生指导关系，以生产通信产品。该项目综合了实验室和海洋学方法，以解决胶状食草动物和海洋微生物之间捕食者-猎物关系的几个具体方面。五种不同类型的胶状食草动物，每一种都有不同的摄食形态和生活史，将在一个拥有丰富多样的天然微生物种群的海洋环境中进行研究。这些目标生物包括远洋被囊动物（海鞘类、尾尾类、多尾类和火虫类）和翼足类。该方法量化了：1)自然海洋环境中的放牧率；2)以大小和形状为重点的颗粒选择性；3)作为测量放牧率和颗粒选择基础的饲料形态和水动力特性。该项目使用了多种技术，包括潜水采样、实验室实验、高速/高分辨率摄像、流式细胞术和DNA测序技术。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The oceans are dominated by microscopic plants and animals (microorganisms) that are at the base of the food web and drive energy and carbon cycles on global scales. Soft jellylike animals called gelatinous grazers specialize in feeding on microorganisms using nets made out of mucus. Gelatinous grazers are abundant in the ocean and have high feeding rates on microorganisms so could have a very strong influence on the abundance and diversity of microorganisms and could change how oceanic food webs are currently understood. However, gelatinous grazers are very fragile and patchy in their distributions so it has been difficult to determine the magnitude and dynamics of these important predator-prey relationships on a meaningful scale using traditional approaches, thus they have typically been disregarded in food web studies. Learning more about the predator-prey relationship between gelatinous grazers and microorganisms will improve understanding of the structure, mechanics, and dynamics of the ocean?s food web, which is a critical economic and ecosystem resource on Earth. This project is determining grazing rates by gelatinous animals on microbes to inform food web models. The project also trains students to communicate, disseminate, and interpret scientific findings. These broader impacts goals will be attained through partnerships at the University of Oregon (Applied Scientific Communication) and Portland State University (Advanced Technical Writing), training of 1 PhD student, 2 undergraduates, and 4 science communication interns, and development of a week-long workshop and establish student mentorship relationships towards production of communication products.The project integrates laboratory and oceanographic approaches to address several specific aspects of the predator-prey relationship between gelatinous grazers and ocean microorganisms. Five distinct types of gelatinous grazers, each with different feeding morphologies and life history, will be studied in an oceanographic setting with an abundant and diverse natural microbial population. These target organisms include pelagic tunicates (salps, appendicularians, doliolods and pyrosomes) and thecosome pteropods. The approach quantifies: 1) grazing rates in the natural ocean environment, 2) particle selectivity with a focus on size and shape and, 3) the morphological and hydrodynamic properties of feeding that underlie the measured grazing rates and particle selection. The project uses a variety of techniques including sampling via SCUBA diving, laboratory experiments, high speed/high resolution videography, flow cytometry, and DNA sequencing techniques.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.