Eyespots are taxonomically widespread colour patterns consisting of large concentric rings that are commonly assumed to protect prey by influencing the behaviours of predators. Although there is ample experimental evidence supporting an anti-predator function of eyespots in terrestrial animals, whether eyespots have a similar deterring function in aquatic animals remains unclear. Furthermore, studies in terrestrial systems suggest that the protective function of eyespots depends on ambient light conditions where predators encounter them, but this effect was never been tested in aquatic environments. Here, we examine how eyespots influence behavioural responses in an aquatic environment under different visual environments, using laboratory-reared three-spined sticklebacks (Gasterosteus aculeatus) as model predators. Specifically, we experimentally examined behavioural responses of sticklebacks towards artificial prey patterns (control vs eyespots) under two different light environment treatments (low vs high). We found that eyespots did not postpone attacks from sticklebacks. However, sticklebacks approaching eyespots stopped more frequently than sticklebacks approaching prey items with a control pattern. Sticklebacks were (marginally) slower to attack prey in the low light treatment, but light level did not influence stickleback behavioural responses towards eyespots. We conclude that that eyespots can modulate some behaviours of an aquatic predator, albeit with a different functional role than previously demonstrated in terrestrial species.

The dataset represents an experimental examination of how sticklebacks respond to eyespot and control stimuli under different light conditions. The experiments were performed in a controlled laboratory setting. The data is derived from real time observation and video analyses. 

The statistical program R is needed to run the code adn the raw data is visible with a program that can read spreadsheets (e.g. Microsof Excel).