The integration of sensors in underwater detectors is of paramount importance, enabling autonomous control and supporting auxiliary functions. However, traditional sensors have faced limitations, prompting the rapid advancement of sensor technologies. As a result, novel bio-inspired sensors have emerged, drawing inspiration from the remarkable adaptations and sensing capabilities of aquatic creatures. This review offers a comprehensive overview of the latest research and developments in the field of bio-inspired sensors inspired by aquatic creatures. It explains the various sensing principles and working principles of biological fish and encompasses an exploration of biological sensory mechanisms, various bioinspired sensor types, essential design principles, material preparations, diverse sensor modalities, and their wide-ranging applications. Of particular interest are their potential implications in revolutionizing fields such as environmental assessment, hydrodynamic and underwater imaging, as well as autonomous control in robotics. Moreover, we delve into the challenges faced in this nascent field, while also identifying future directions and underscoring the need for innovation and cross-disciplinary collaborations.