title: Behavioural thresholds for diffuse illumination in the goldfish.
abstract: Thresholds for diffuse, broad-band illumination were obtained for the goldfish (Carassius auratus) by avoidance conditioning. The light source was a television cathode-ray tube whose output was controlled over a range of 140 dB by a combination of 'brightness' control, blanking of scan lines, and neutral density filters. The threshold was calculated in terms of irradiance to be 2-9 X 10(-6) muW cm-2 (+/- a standard deviation of 1-4). The determination of absolute, rather than relative, values, and the use of overhead, diffuse illumination provided data that would be ecologically and behaviourally relevant.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D003530:Cyprinidae / Q000502:physiology*; D006054:Goldfish / Q000502:physiology*; D008027:Light; D013057:Spectrum Analysis; D014796:Visual Perception / Q000502:physiology*