Vision in the peafowl (Aves : Pavo cristatus)


Autoria(s): Hart, N. S.
Data(s)

01/01/2002

Resumo

The visual sense of the Indian blue-shouldered peafowl Pavo cristatus was investigated with respect to the spectral absorption characteristics of the retinal photoreceptors, the spectral transmittance of the ocular media and the topographic distribution of cells in the retinal ganglion cell layer. Microspectrophotometry revealed a single class of rod, four spectrally distinct types of single cone and a single class of double cone. In the case of the single cone types, which contained visual pigments with wavelengths of maximum absorbance (lambda(max)) at 424, 458, 505 and 567 nm, spectral filtering by the ocular media and the different cone oil droplets with which each visual pigment is associated gives predicted peak spectral sensitivities of 432, 477, 537 and 605 nm, respectively. Topographic analysis of retinal ganglion cell distribution revealed a large central area of increased cell density (at peak, 35,609 cells mm(-2)) with a poorly defined visual streak extending nasally. The peafowl has a calculated maximum spatial resolution (visual acuity) in the lateral visual field of 20.6 cycles degrees(-1). These properties of the peafowl eye are discussed with respect to its visual ecology and are compared with those of other closely related species.

Identificador

http://espace.library.uq.edu.au/view/UQ:63475

Idioma(s)

eng

Publicador

The Company of Biologists Ltd.

Palavras-Chave #Biology #Microspectrophotometry #Colour Vision #Avian Retina #Visual Pigment #Cone Oil Droplet #Photoreceptor #Visual Ecology #Ganglion Cell Topography #Ocular Media #Peafowl #Pavo Cristatus #Ganglion-cell Layer #Cone Oil Droplets #Starling Sturnus-vulgaris #Visual Pigments #Photoreceptor Distribution #Procellariiform Seabirds #Regional Specialization #Quantitative-analysis #Spectral Sensitivity #C1 #270604 Comparative Physiology #730111 Hearing, vision, speech and their disorders
Tipo

Journal Article