Figure 5.

Circadian behaviour of A. pulcher under fully naturalistic vs. constant-luminance natural colour-changing conditions. (A) Activity under conditions in which both light intensity and colour of illumination in the enclosure changed in a naturalistic manner. During the first 12 hours of the photoperiod, a 480 nm opsin would be stimulated as would be the rods and cones; there was darkness for the second 12 hours; black line = activity, red line = ratio of L-cone to S-cone quantal catch. (B) Behaviour under the luminance constant stimulation regime. Quantal catches of pigments with a 480 nm spectral peak were kept constant for the full 24-hours photoperiod but wavelength content of the illumination changes in a naturalistic manner mimicking daily changes in the colour of the sky; red and black traces as above. (C) Behaviour under same conditions as (B), but onset of stimulus advanced 4 hours. Black trace = activity; red trace = standardized L:S quantal catch ratio; blue trace = standardized S-cone quantal catch. (D) Behaviour under free-running, 12D:12D, conditions. The smaller panels to the right of A-C illustrate the duration and intensities of the LEDs (red = 630 nm LED; aqua = 505 nm LED; violet = 420 nm LED) during each experiment.