title: The importance of ultraviolet and near-infrared sensitivity for visual discrimination in two species of lacertid lizards.
abstract: Male and female Lacertid lizards often display conspicuous coloration that is involved in intraspecific communication. However, visual systems of Lacertidae have rarely been studied and the spectral sensitivity of their retinal photoreceptors remains unknown. Here, we characterise the spectral sensitivity of two Lacertid species from contrasting habitats: the wall lizard Podarcis muralis and the common lizard Zootoca vivipara. Both species possess a pure-cone retina with one spectral class of double cones and four spectral classes of single cones. The two species differ in the spectral sensitivity of the LWS cones, the relative abundance of UVS single cones (potentially more abundant in Z. vivipara) and the coloration of oil droplets. Wall lizards have pure vitamin A1-based photopigments, whereas common lizards possess mixed vitamin A1 and A2 photopigments, extending spectral sensitivity into the near infrared, which is a rare feature in terrestrial vertebrates. We found that spectral sensitivity in the UV and near infrared improves discrimination of small variations in throat coloration among Z. vivipara. Thus, retinal specialisations optimise chromatic resolution in common lizards, indicating that the visual system and visual signals might co-evolve.
authors.affiliation: CNRS UMR 7618, iEES Paris, Université Pierre et Marie Curie, 75005 Paris, France CNRS UMR 7179, Département d'Ecologie et de Gestion de la Biodiversité, Muséum National d'Histoire Naturelle, 91800 Brunoy, France melissa.martin@snv.jussieu.fr.
authors.forename: Mélissa
authors.initials: M
authors.lastname: Martin
authors.affiliation: CNRS UMR 7618, iEES Paris, Université Pierre et Marie Curie, 75005 Paris, France CNRS UMS 3194, CEREEP - Ecotron IleDeFrance, École Normale Supérieure, 77140 St-Pierre-lès-Nemours, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Le Galliard
authors.affiliation: CNRS UMR 7618, iEES Paris, Université Pierre et Marie Curie, 75005 Paris, France ESPE de Paris-Université Sorbonne Paris IV, 75016 Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Meylan
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Ellis R
authors.initials: ER
authors.lastname: Loew
mesh_terms: D000818:Animals; D004192:Discrimination, Psychological; D017753:Ecosystem; D005260:Female; D008116:Lizards / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D012160:Retina / Q000166:cytology / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012168:Retinal Pigments / Q000737:chemistry; D012880:Skin Pigmentation; D013045:Species Specificity; D014466:Ultraviolet Rays; D014796:Visual Perception
chemical_list: D012168:Retinal Pigments
keywords: Chromatic resolution; Colour vision; Cone abundance; Podarcis muralis; UV sensitivity; Vitamin A1/A2-based pigments; Zootoca vivipara