spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Loew, E. R.
Right arrow Articles by Provencio, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Loew, E. R.
Right arrow Articles by Provencio, I.
The Journal of Experimental Biology 205, 927-938 (2002)
© 2002 The Company of Biologists Limited

Visual pigments and oil droplets in diurnal lizards : a comparative study of Caribbean anoles

Ellis R. Loew1,*, Leo J. Fleishman2, Russell G. Foster3,{dagger} and Ignacio Provencio3,{ddagger}

1 Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
2 Department of Biology, Union College, Schenectady, NY 12308, USA
3 Department of Biology, University of Virginia, Charlottesville, VA 22903, USA
{dagger} Present address: Department of Integrative and Molecular Neuroscience, Division of Neuroscience and Psychological Medicine, Imperial College School of Medicine, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK
{ddagger} Present address: Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA

* e-mail: ERL1{at}cornell.edu

Accepted 21 January 2002

We report microspectrophotometric (MSP) data for the visual pigments and oil droplets of 17 species of Caribbean anoline lizard known to live in differing photic habitats and having distinctly different dewlap colors. The outgroup Polychrus marmoratus was also examined to gain insight into the ancestral condition. Except for Anolis carolinensis, which is known to use vitamin A2 as its visual pigment chromophore, all anoline species examined possessed at least four vitamin-A1-based visual pigments with maximum absorbance ({lambda}max) at 564, 495, 455 and 365 nm. To the previously reported visual pigments for A. carolinensis we add an ultraviolet-sensitive one with {lambda}max at 365 nm. Five common classes of oil droplet were measured, named according to apparent color and associated with specific cone classes — yellow and green in long-wavelength-sensitive (LWS) cones, green only in medium-wavelength-sensitive (MWS) cones and colorless in short-wavelength-sensitive (SWS) and ultraviolet-sensitive (UVS) cones. MSP data showed that the colorless droplet in the SWS cone had significant absorption between 350 and 400 nm, while the colorless droplet in the UVS cone did not. The pattern for Polychrus marmoratus was identical to that for the anoles except for the presence of a previously undescribed visual cell with a rod-like outer segment, a visual pigment with a {lambda}max of 497 nm and a colorless oil droplet like that in the UVS cones. These findings suggest that anoline visual pigments, as far as they determine visual system spectral sensitivity, are not necessarily adapted to the photic environment or to the color of significant visual targets (e.g. dewlaps).

Key words: vision, microspectrophotometry, anoline, lizard, Anolis carolinensis, Polychrus marmoratus, visual pigment, oil droplet, photoreceptor






© The Company of Biologists Ltd 2002