title: Diversity of photoreceptor arrangements in nocturnal, cathemeral and diurnal Malagasy lemurs.
abstract: The lemurs of Madagascar (Primates: Lemuriformes) are a monophyletic group that has lived in isolation from other primates for about 50 million years. Lemurs have diversified into species with diverse daily activity patterns and correspondingly different visual adaptations. We assessed the arrangements of retinal cone and rod photoreceptors in six nocturnal, three cathemeral and two diurnal lemur species and quantified different parameters in six of the species. The analysis revealed lower cone densities and higher rod densities in the nocturnal than in the cathemeral and diurnal species. The photoreceptor densities in the diurnal Propithecus verreauxi indicate a less "diurnal" retina than found in other diurnal primates. Immunolabeling for cone opsins showed the presence of both middle-to-longwave sensitive (M/L) and shortwave sensitive (S) cones in most species, indicating at least dichromatic color vision. S cones were absent in Allocebus trichotis and Cheirogaleus medius, indicating cone monochromacy. In the Microcebus species, the S cones had an inverse topography with very low densities in the central retina and highest densities in the peripheral retina. The S cones in the other species and the M/L cones in all species had a conventional topography with peak densities in the central area. With the exception of the cathemeral Eulemur species, the eyes of all studied taxa, including the diurnal Propithecus, possessed a tapetum lucidum, a feature only found among nocturnal and crepuscular mammals.
authors.affiliation: Max Planck Institute for Brain Research, Max-von-Laue-Straße 4, 60438, Frankfurt am Main, Germany.|Ernst Strüngmann Institute for Neuroscience, Deutschordenstraße 46, 60528 Frankfurt am Main, Germany.|Institute of Cellular and Molecular Anatomy, Dr. Senckenbergische Anatomie, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
authors.forename: Leo
authors.identifier: 0000-0002-8141-0911
authors.initials: L
authors.lastname: Peichl
authors.affiliation: Department Biology II, Ludwig-Maximilians University Munich, Großhaderner Straße 2-4, 82152, Martinsried-Planegg, Germany.|Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kaiser
authors.affiliation: Département de Zoologie et Biodiversité Animale, Université d'Antananarivo, BP 906, Antananarivo 101, Madagascar.
authors.forename: Felix
authors.initials: F
authors.lastname: Rakotondraparany
authors.affiliation: School of Veterinary Medicine, University of Wisconsin, 2015 Linden Drive, Madison, Wisconsin, 53706.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Dubielzig
authors.affiliation: The Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, Illinois, 60605.|Association Vahatra, BP 3972, Antananarivo 101, Madagascar.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Goodman
authors.affiliation: Behavioral Ecology and Sociobiology Unit, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany.|Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, University Göttingen, Kellnerweg 6, 37077, Göttingen, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kappeler
mesh_terms: D000818:Animals; D007900:Lemur / Q000033:anatomy & histology*; D010786:Photoreceptor Cells / Q000166:cytology*; D013045:Species Specificity
keywords: RRID: AB_2158332; RRID: AB_2313807; RRID: AB_2315259; Strepsirrhini; color vision; cone opsin; primate retina; prosimian; visual pigment