European seabass, Dicentrarchus labrax, show no significant response to infrared light

Infrared (IR) light is widely accepted as a non-intrusive lighting for discreet observation but relevant studies are scarce. The response of European seabass Dicentrarchus labrax (Linnaeus 1758) towards IR light was tested during laboratory experiments alternating sequences of IR light and dark conditions. Swimming trajectories were extracted from hydroacoustic videos and behavioural metrics (e.g. speed, bearings) were quantified from the D. labrax movement patterns. D. labrax showed no preference nor deterrence towards IR light, supporting the use of discreet IR light as an alternative to visible light for monitoring unbiased D. labrax behaviour.