Meeting Abstract

P1.110  Tuesday, Jan. 4  Markov models of jellyfish pulse cycles and the resulting fluid flows RODRIGUEZ, Terry*; HAMLET, Christina; GYOERKOE , Megan; MILLER, Laura; University of North Carolina at Chapel Hill tjrodrig@email.unc.edu

The upside-down jellyfish, Cassiopea spp., is particularly well suited for kinematic studies since it spends most of its time resting on the seafloor with its oral arms extended upward. These jellyfish use cycles of bell contraction and expansion to facilitate the movement of water for food capture as well as oxygen and waste exchange. In this study, we measured contraction, expansion, and pause times over the course of many contraction cycles. Of particular interest was the length of the rest period between the completion of expansion of the bell and the contraction of the next cycle. We assumed the cycle period can be characterized as a Markov process and developed a model that simulates cycle times using the distributions found empirically. In particular, we found that the contraction cycles switch between long and short periods that depend upon the length of the rest period between expansion and contraction. We used immersed boundary simulations to explore the fluid flow generated by long and short pulse cycles and found that the durations of the pauses have implications for the efficiency of particle capture and exchange.