Effects of the neuromechanical inputs on the swimming performance of an oblate jellyfish

The replication of the neuro-mechanical processes contributing to locomotion can advance the understanding of jellyfish biology and their environmental interactions. To this end, we propose a comprehensive simulation framework to deduce fundamental correlations between electrophysiological inputs and propulsive performance. The key simplifying assumption of axisymmetric field allows to work out a sophisticated model with a reasonable number of degrees of freedom. The monodomain model drives the diffusion of the electrophysiological excitation waves over the endothelial tissue, whereas a Hodgkin-Huxley neuron model addresses the reactive effects. Consequently, the electrical stimulus is translated into an active contraction of the subumbrellar muscle fibers whereas the outer part of the solid domain, which mimics the mesoglea, is modelled as a passive part, being responsible for the elastic recoil. Both activation parameters and material properties are tuned to match experimental observations from in-vivo experiments. The computational framework is completed by the axisymmetric Navier-Stokes solver, which, in conjunction with a direct-forcing immersed boundary treatment, incorporates the full excitation-contraction-locomotion scenario.