Microspectrophotometric studies on the visual pigment in the intact retina of the goldfish, Carassius auratus (Linn.).

The visual pigments in intact retinas of the common goldfish were examined by microspectrophotometry. Difference spectra free of photoproduct contamination had absorbance maxima at lambda527 nm +/- 2 nm. The average pigment density, about 0.32, was almost invariant with regard to retinal location and specimen size. Traces of a photoproduct absorbing maximally at lambda480-490 nm were found. The normalized "absorbance" curve deviated from standard templates. It was suggested that this was an effect of cross-coupling of energy and among photoreceptors. Finally, known action spectra show a red shift relative to the absorbance spectra measured.