Visual detection of UV cues by adult zebrafish (Danio rerio).

Visual sensitivity to ultraviolet (UV) light is widespread in the animal kingdom. Many studies on UV vision have utilized physiological and/or anatomical methods to determine whether animals are visually sensitive to UV wavelengths. However, ultimately behavioral methods can reveal whether retinal UV sensitivity results in perceptual detection of UV stimuli. For the widely studied zebrafish (Danio rerio), the adult retina possesses cone photoreceptors that are sensitive to UV light. Here, we used a behavioral technique, the escape response assay, to test whether adult zebrafish can visually detect and behaviorally respond to visual cues that reflect UV. We found that adult zebrafish robustly respond to UV reflecting cues under UV light while showing no responses to the same cues under no UV light. From our results, we confirm that adult zebrafish can visually detect UV reflecting cues and show that UV perceptual sensitivity is functional in adult zebrafish. Our study highlights the utility of the fish escape response assay for UV visual behavior research.