NSF Award
2114170
Siphonophores are a highly diverse group of colonial jellyfish that are widespread and important components of the world’s largest ecosystem, the midwaters of the open ocean. Very little is known about how these jellyfish function. It is thought that the majority of siphonophores spend their entire life suspended in water and move through the ocean via jet propulsion. However, this is likely a gross over-simplification of how this highly diverse group of jellyfish function. The goal of this project is to study how siphonophore shape and body design are related to how they swim, and their swimming and feeding behavior. The main reason so little is understood about these jellyfish, and really most other gelatinous animals in the open ocean, is that scientists have had very limited access to these delicate, remote animals. However, our team has developed tools and techniques that enable our team to study these animals in their natural habitat. In this project, siphonophore swimming movements and mechanics will be quantified using a combination of novel imaging tools controlled by both SCUBA divers and remotely operated vehicles (ROVs). This research will provide an understanding of how the body form of these jellyfish determines how they function. This is critical information for understanding their role in the largest ecosystem of the world. It is also information that can be used by engineers to design better underwater vehicles that move more efficiently and are more maneuverable than current state-of-the-art technology.<br/><br/>Siphonophores are colonial cnidarians that are widespread, important components of open ocean communities. It is thought that the majority of siphonophore species spend their entire life suspended in water moving through the ocean via jet propulsion. However, this is likely a gross over-simplification of how this highly diverse group of jellyfish function. The historic obstacle to broader understanding of how these jellyfish function has been the difficulty of accessing these animals. Imaging advances that our team has made in both blue-water SCUBA and with remotely operated vehicles (ROVs) have addressed these limitations. In situ high-speed imaging, bright field, and particle image velocimetry (PIV) for both diver-controlled and ROV operations now allow detailed quantitative measurements of propulsive mechanisms and swimming behavior (short- and long-term) for both surface and deep-dwelling siphonophores. This combination of in situ systems enables our team to collect the multi-scale morphological, kinematic, hydrodynamic, and behavioral data required to be able to establish the benefits and limits of different siphonophore body forms. These results will allow a broad comparison of form and function that is required to understand the trophic role of different siphonophores in the pelagic ecosystem. The results will also contribute to understanding design principles of these colonial species that will inform novel engineered designs that combine jet propulsors in small vehicles, and could ultimately expand exploration and discovery in the oceans. This project will train young scientists, and with the help of our partners, will use video and visualizations for education outreach and engagement of the public.<br/><br/>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.
