Visual pigment absorbance and scotopic spectral sensitivity in the goldfish, Carassius auratus.

Factors relating to the comparison of the absorbance spectra of visual pigments to experimentally determined relative spectral sensitivities of the eye are discussed with specific reference to the goldfish. It is concluded that the experimentally determined scotopic sensitivity of the goldfish can be directly related to the absorbance of goldfish porphyropsin without the need to infer input from long wavelength-sensitive cones.