title: The scotopic and photopic visual sensitivity in the nocturnal tree frog Agalychnis callidryas.
abstract: The red-eyed tree frog (Agalychnis callidryas) is endemic to the rainforests of Central America. During the night, it hunts for insects in the treetops whereas at daytime, the frogs rest under leaves. In the present study we determined the relative visual sensitivity spectrum of this nocturnal frog species by ERG recordings in both the dark- and light-adapted state. In both the scotopic- and photopic-sensitivity curve, we found only minor individual variations among the tested individuals. The sensitivity maximum of the scotopic curve was determined at 500 nm, which matches the absorption properties of the RH1-visual pigment expressed in the red rods of frogs. The sensitivity maximum of the photopic curve was found at 545 nm which is close to the absorption maximum of the LWS pigment type expressed in most cones of the frog retina. The threshold curves determined by ERG recordings here reveal no unusual features in the sensitivity spectrum of the red-eyed tree frog that could be interpreted as adaptations for its strictly nocturnal life style.
authors.affiliation: Auditory Neuroethology and Neurobiology, Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany. arne.liebau@web.de.|Center for Systems Neuroscience, Hannover, Germany. arne.liebau@web.de.
authors.forename: Arne
authors.initials: A
authors.lastname: Liebau
authors.affiliation: Department of Veterinary Medicine, Hesse State Laboratory, Schubertstraße 60, 35392, Giessen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Eisenberg
authors.affiliation: Auditory Neuroethology and Neurobiology, Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.|Center for Systems Neuroscience, Hannover, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Esser
mesh_terms: D000818:Animals; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011898:Ranidae / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D013045:Species Specificity; D014785:Vision, Ocular / Q000502:physiology*
keywords: Amphibia; Spectral sensitivity; Vision; Visual pigment