Start of funding 01.07.2017

Moving earstones: Advanced modeling of complex otolith motion in the fish ear

Dr. Tanja Schulz-Mirbach
Ludwig-Maximilians-University of Munich
Department of Biology II - Zoology

Prof. Petr Krysl
University of California, San Diego
Department of Structural Engeneering



Modern bony fishes (teleosts) like zebrafish are important model organisms to study deafness and balance disorders in human medicine. Yet, the actual motion of the otolith (“ear stone”) relative to the underlying sensory epithelium in the fish ear remains widely elusive and modeling of otolith motion and the rare experimental studies have yielded conflicting results. Based on a recent study that indicates a shape-dependent pattern of otolith motion, we will elucidate what parameters in the previous modeling of otolith motion have to be adjusted in order to closely fit the experimental data obtained during a recent project at the European Synchrotron Radiation Facility (ESRF, Grenoble). We will then extend the advanced modelling to include the gas-filled swim bladder which can act as an accessory hearing structure (pressure-to-particle motion transducer) and the relative motion between otolith and the underlying sensory epithelium. We expect that our extended modeling will provide a fundamental basis for a better understanding of otolith motion in fish ears and will help to shed light on the role of species-specific otolith shapes in fish hearing. Thus, it could also serve as a starting point for more precise predictions of the effects of increasing ocean acidification due to global climate change which has been shown to affect otolith mineralization and which is hypothesized to affect fish hearing and behavior.