Visual pigments and oil droplets from six classes of photoreceptor in the retinas of birds

Microspectrophotometric examination of the retinal photoreceptors of the budgerigar (shell parakeet), Melopsittacus undulatus (Psittaciformes) and the zebra finch, Taeniopygia guttata (Passeriformes), demonstrate the presence of four, spectrally distinct classes of single cone that contain visualpigments absorbing maximally at about 565, 507, 430–445 and 360–380 nm. The three longer-wave cone classes contain coloured oildroplets acting as […]