Phototactic responses of anuran amphibians to monochromatic stimuli of equal quantum intensity.
The phototactic responses of anuran amphibians to narrow-band monochromatic stimuli of equal quantum intensity were measured for the first time in eight new experiments. The unimodal spectral response, obtained from dark-adapted American toads (Bufo americanus), peaks near 626 THz of frequency (480 nm wavelength). The bimodal, U-shaped spectral response, obtained from dark-adapted tailed frogs (Ascaphus truei), has the anti-mode at about 589 THz (510 nm) and is not merely the spectral mirror-image of the unimodal response. Absolute level of the spectral stimuli of equal quantum intensity did not affect the spectral response of dark-adapted toads, but light-adaptation enhanced a component that has the same spectral peak as the visual pigment absorption spectrum of principal and single cones of the frog's retina.
D000818:Animals; D001001:Anura / Q000502:physiology*; D002025:Bufonidae / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D003623:Dark Adaptation; D008029:Lighting; D010786:Photoreceptor Cells / Q000502:physiology; D012168:Retinal Pigments / Q000502:physiology
D012168:Retinal Pigments