Preference of juvenile tiger puffer for light spectrum and tank colours based on different body size and breeding background

As important environmental factors, the light spectra and tank colours have not received sufficient attention. Most fishes have the ability to perceive environment, distinguish colours, and exhibit preferences or aversions towards different environments, which can provide a reference for the design of their rearing environment. Tiger puffer (Takifugu rubripes) is an important mariculture species in China and East Asia, but its preference for illumination spectra and tank colours is unclear. This study focuses on the preferences of juvenile tiger puffers for different spectra and tank background colours in different rearing backgrounds and body sizes. The experiments were conducted in a preference testing device, and the behavioural videos were recorded and analysed using a motion behaviour tracking system (EthoVision XT 12). The results show that the puffers showed preference for short-wavelength lights ((i.e., cyan, green, etc.), avoidance of long-wavelength light (i.e., red) and less stay time in the full light spectrum and dark. For tank colours, the puffers showed a preference for light background colours (i.e., white), and avoidance of deep background colours (i.e., dark, red, etc.). Fish body sizes and original breeding environment could significantly affect the selective preference of juvenile puffer (P