Biomechanics of intra-oral water flow generation in fish – IOFLOW

The head of a fish is a remarkably mobile structure used for vital functions such as food capture and respiration. But how do fish efficiently generate the water flows that specifically meet the biomechanical requirements of these functions? Although the water flow inside the mouth cavity fulfils a key role during suction feeding and ventilation of the gills, difficult optical access to this cavity and current limitations of existing mathematical models make it still poorly understood. Without this knowledge, however, the extraordinary cranial diversity observed in this group remains largely unexplained.

The objective of the IOFLOW project is to gain fundamental insights into the dynamics of intra-oral flows and how these flows are generated by motions of the cranial musculoskeletal system. My research will focus on three mechanically related, yet functionally distinct, processes in two model species with a generalized teleost body plan: suction feeding, filter feeding, and respiratory ventilation. I will pioneer the use of a complementary set of new methods to quantitatively analyse the intra-oral hydrodynamics: 3D x-ray particle tracking velocimetry, endoscopic laser particle image velocimetry, and 3D computational fluid dynamic modelling. These methods have been developed recently for engineering purposes, and I will expand and optimize their usage protocols for related biomechanical and functional morphological research.

The novel experiments and mathematical models proposed will break new ground and make it possible for me to generate and test new hypotheses on the adaptive function of this system. My research will significantly advance this field of research in clarifying how natural selection has shaped the cranial anatomy and kinematics observed in this successful and diverse group of vertebrates and has significant potential for biomimetic engineering applications.