Blue light preconditioning as a novel strategy for reducing transport stress in zebrafish

In recent years, zebrafish have become increasingly important in experimental sciences, with transportation being a critical step in their use. However, the vibrations during transportation often induce stress responses in the fish, impairing their physiological functions and even leading to death. As a key environmental modulator, light conditions have been shown to significantly affect the physiological state of fish. In this study, we developed a novel experimental setup integrating an adjustable light source and vibration simulation system to replicate transportation conditions and explore the optimal strategies to alleviate fish stress. First, we tested the wavelength preferences of zebrafish in both static and vibrating environments, finding that zebrafish exhibited a significant preference for 455 nm blue light. Subsequently, under consistent light power and illuminance, we measured the impact of different wavelengths of light on zebrafish anxiety behaviors over a two-month period. Further simulated transportation experiments showed that long-term (2 h daily for 14 days) exposure to blue light (455 nm) effectively reduced anxiety-related behaviors in the simulated transportation environment, while short-term exposure to blue light during transportation alone did not alleviate stress. This study confirms the effectiveness of specific blue light (455 nm) in reducing stress responses induced by vibration and provides key insights into optimizing zebrafish transportation protocols, with a particular emphasis on the necessity of light adaptation prior to transport.