UNVEILING HISTORICAL HYDRODYNAMIC CUES AS A SENSORY LANDSCAPE FOR AQUATIC NAVIGATION TASKS

Understanding how aquatic animals perceive and respond to hydrodynamic cues requires experimental tools capable of resolving low-amplitude pressure fluctuations over biologically relevant spatial and temporal scales. Recent advances in embedded electronics have enabled the development of custom pressure- sensing instruments capable of capturing the subtle hydrodynamic traces left in the wake of swimming fish, helping to clarify how such signals may contribute to social interactions. We present a modular distributed pressure-sensing network designed to characterize fish-generated hydrodynamic signatures in confined aquatic environments. The system consists of 96 differential pressure sensors distributed over a 1 m2 wall-mounted array, synchronized through a wireless time-coherent acquisition architecture operating at 200 Hz. The platform achieves a noise floor of ±0.15 Pa, a dynamic range of ±500 Pa, and an effective bandwidth of 0.3–30 Hz, enabling the detection of weak, spatially distributed pressure perturbations generated by freely swimming fish. Unlike conventional point-wise hydrophones or optical velocimetry techniques, the proposed approach enables long-duration, spatially resolved mapping of pressure fields with minimal intrusion and manageable data volumes. A dedicated synchronization framework integrates pressure recordings with high-speed video tracking, allowing reconstruction of spatio-temporal pressure footprints associated with individual trajectories. Long-duration experiments demonstrate the ability to capture evolving hydrodynamic wakes and transient pressure structures generated by swimming fish. This platform provides a new experimental basis for investigating lateral-line-mediated perception and hydrodynamic interactions in aquatic systems. The modular architecture is scalable up to 240 sensing points and adaptable to different tank geometries, offering a versatile tool for interdisciplinary research at the interface of fluid dynamics, sensory biology, and behavioral ecology.