Collaborative Research: MUCUS: Measuring and Understanding the Cassiopea Use of Space

In recent decades over 50% of living coral reefs have been lost due in large part to climate change and other anthropogenic factors. In contrast, jellyfish are overpopulating part of the oceans with an increased rate of blooms since 1950. Mucus produced by jellyfish may allow them to colonize new locations, thrive in warm environments, and provide glycoproteins for the surrounding community. Although there has been significant work exploring the role that mucus plays in vertebrate animals and how mucus affects microorganism swimming at the microscale, our understanding of the mechanical properties of jellyfish mucus, which may be up to tens of centimeters in thickness, is limited. The broad goal of this project is to determine if the success of the jellyfish Cassiopea and related species is due in part to their significant production of mucus and, associated with it, venom within stinging cells released by the jellyfish in structures called cassiosomes. This project supports interdisciplinary training for a postdoctoral fellow, two graduate students, and at least four undergraduates at the interface of biomechanics, mathematical modeling, physiology, and ecology. Training includes opportunities for students to connect with researchers at the Smithsonian Institution, the Key Largo Marine Research Laboratory, and internationally in Japan and Brazil. While scientific studies and news stories increasingly report on the reduction of distribution ranges for a number of marine species, scyphozoan jellyfish, conversely, appear to be undergoing range expansions due to increased bloom events. Temperature appears to be a major factor, enabling a longer reproduction period, as are anthropogenic factors that result in an increase in asexual reproduction. Increasing findings also suggest that jellyfish mucus may confer an advantage by playing a protective role against environmental stress and increasing temperatures while simultaneously enhancing feeding efficiency. To understand how mucus aids in the success of Cassiopea and other rhizostome jellyfish, the research team will use a highly interdisciplinary approach that combines the following tools: (1) mathematics and engineering tools to characterize the physical properties of the mucus and the motility of plankton and cassiosomes within it, (2) eDNA, traditional sampling, and the literature to benchmark how Cassiopea species distributions are changing, and (3) Nanopore eRNA sequencing to characterize the venom and other mucus proteins of interest and how expression of these proteins changes over time and with seasonal temperature fluctuations. The team will then apply these tools to (1) assess whether and how mucus reduces swimming speeds in a variety of planktonic prey while permitting or possibly enhancing active locomotion in cassiosomes, (2) determine the mechanisms by which mucus protects jellyfish from foreign objects and irritants, and (3) evaluate if and how mucus, cassiosomes, and nematocysts aid in the range expansion of Cassiopea by creating dominant mono-specific or mono-generic communities. In addition to providing interdisciplinary training opportunities for a postdoctoral fellow and graduate and undergraduate students, the award supports an annual workshop on Cassiopea biology at the Key Largo Marine Research Laboratory which will be expanded to incorporate presentations and tutorials related to this research project. This award is co-funded by the BIO-IOS-Physiological Mechanisms and Biomechanics program and the GEO-OCE-Biological Oceanography program. 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.