ERG-DETERMINED SPECTRAL SENSITIVITY OF OCTOPUS

The ERG-determined scotopic spectral sensitivity curve of the intact, anesthetized octopus was a broad curve which peaked at 480 nm with no secondary peaks. Adaptation to white light resulted in a narrowing of the curve but the λmax remained at 480 nm. Adaptation to blue, green or red light did not induce a shift in the λmax but resulted in a depression and narrowing of the sensitivity curve. Because of the absence of a Purkinje shift and the narrowing of the sensitivity curve following light-adaptation, it was concluded that the broadness of the sensitivity curve was due to a high effective retinal density of the photopigment and that only one system was present in the retina of the octopus. © 1968.