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Author Landgren, E.; Fritsches, K.; Brill, R.; Warrant, E.
Title The visual ecology of a deep-sea fish, the escolar Lepidocybium flavobrunneum (Smith, 1843) Type Journal Article
Year 2014 Publication Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences Abbreviated Journal Philos Trans R Soc Lond B Biol Sci
Volume 369 Issue 1636 Pages 20130039
Keywords (down) Vision; Animals
Abstract Escolar (Lepidocybium flavobrunneum, family Gempylidae) are large and darkly coloured deep-sea predatory fish found in the cold depths (more than 200 m) during the day and in warm surface waters at night. They have large eyes and an overall low density of retinal ganglion cells that endow them with a very high optical sensitivity. Escolar have banked retinae comprising six to eight layers of rods to increase the optical path length for maximal absorption of the incoming light. Their retinae possess two main areae of higher ganglion cell density, one in the ventral retina viewing the dorsal world above (with a moderate acuity of 4.6 cycles deg(-1)), and the second in the temporal retina viewing the frontal world ahead. Electrophysiological recordings of the flicker fusion frequency (FFF) in isolated retinas indicate that escolar have slow vision, with maximal FFF at the highest light levels and temperatures (around 9 Hz at 23 degrees C) which fall to 1-2 Hz in dim light or cooler temperatures. Our results suggest that escolar are slowly moving sit-and-wait predators. In dim, warm surface waters at night, their slow vision, moderate dorsal resolution and highly sensitive eyes may allow them to surprise prey from below that are silhouetted in the downwelling light.
Address Lund Vision Group, Department of Biology, University of Lund, , Solvegatan 35, 22362 Lund, Sweden
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-8436 ISBN Medium
Area Expedition Conference
Notes PMID:24395966; PMCID:PMC3886327 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1092
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Author Moran, D.; Softley, R.; Warrant, E.J.
Title The energetic cost of vision and the evolution of eyeless Mexican cavefish Type Journal Article
Year 2015 Publication Science Advances Abbreviated Journal Science Advances
Volume 1 Issue 8 Pages e1500363-e1500363
Keywords (down) vision; animals
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2375-2548 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1264
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Author Stockl, A.L.; O'Carroll, D.C.; Warrant, E.J.
Title Neural Summation in the Hawkmoth Visual System Extends the Limits of Vision in Dim Light Type Journal Article
Year 2016 Publication Current Biology : CB Abbreviated Journal Curr Biol
Volume 26 Issue 6 Pages 821-826
Keywords (down) Vision; Animals
Abstract Most of the world's animals are active in dim light and depend on good vision for the tasks of daily life. Many have evolved visual adaptations that permit a performance superior to that of manmade imaging devices [1]. In insects, a major model visual system, nocturnal species show impressive visual abilities ranging from flight control [2, 3], to color discrimination [4, 5], to navigation using visual landmarks [6-8] or dim celestial compass cues [9, 10]. In addition to optical adaptations that improve their sensitivity in dim light [11], neural summation of light in space and time-which enhances the coarser and slower features of the scene at the expense of noisier finer and faster features-has been suggested to improve sensitivity in theoretical [12-14], anatomical [15-17], and behavioral [18-20] studies. How these summation strategies function neurally is, however, presently unknown. Here, we quantified spatial and temporal summation in the motion vision pathway of a nocturnal hawkmoth. We show that spatial and temporal summation combine supralinearly to substantially increase contrast sensitivity and visual information rate over four decades of light intensity, enabling hawkmoths to see at light levels 100 times dimmer than without summation. Our results reveal how visual motion is calculated neurally in dim light and how spatial and temporal summation improve sensitivity while simultaneously maximizing spatial and temporal resolution, thus extending models of insect motion vision derived predominantly from diurnal flies. Moreover, the summation strategies we have revealed may benefit manmade vision systems optimized for variable light levels [21].
Address Department of Biology, University of Lund, Solvegatan 35, 22362 Lund, Sweden
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes PMID:26948877 Approved no
Call Number LoNNe @ kyba @ Serial 1374
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Author Warrant, E.; Dacke, M.
Title Visual Navigation in Nocturnal Insects Type Journal Article
Year 2016 Publication Physiology (Bethesda, Md.) Abbreviated Journal Physiology (Bethesda)
Volume 31 Issue 3 Pages 182-192
Keywords (down) Vision; Animals
Abstract Despite their tiny eyes and brains, nocturnal insects have evolved a remarkable capacity to visually navigate at night. Whereas some use moonlight or the stars as celestial compass cues to maintain a straight-line course, others use visual landmarks to navigate to and from their nest. These impressive abilities rely on highly sensitive compound eyes and specialized visual processing strategies in the brain.
Address Department of Biology, Lund Vision Group, University of Lund, Lund, Sweden
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1548-9221 ISBN Medium
Area Expedition Conference
Notes PMID:27053732 Approved no
Call Number LoNNe @ kyba @ Serial 1417
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Author Foster, J.J.; Smolka, J.; Nilsson, D.-E.; Dacke, M.
Title How animals follow the stars Type Journal Article
Year 2018 Publication Proceedings. Biological Sciences Abbreviated Journal Proc Biol Sci
Volume 285 Issue 1871 Pages
Keywords (down) Vision; Animals
Abstract Throughout history, the stars have provided humans with ever more information about our world, enabling increasingly accurate systems of navigation in addition to fuelling some of the greatest scientific controversies. What information animals have evolved to extract from a starry sky and how they do so, is a topic of study that combines the practical and theoretical challenges faced by both astronomers and field biologists. While a number of animal species have been demonstrated to use the stars as a source of directional information, the strategies that these animals use to convert this complex and variable pattern of dim-light points into a reliable 'stellar orientation' cue have been more difficult to ascertain. In this review, we assess the stars as a visual stimulus that conveys directional information, and compare the bodies of evidence available for the different stellar orientation strategies proposed to date. In this context, we also introduce new technologies that may aid in the study of stellar orientation, and suggest how field experiments may be used to characterize the mechanisms underlying stellar orientation.
Address Department of Biology, Lund University, Solvegatan 35, Lund 223 62, Sweden
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-8452 ISBN Medium
Area Expedition Conference
Notes PMID:29367394 Approved no
Call Number LoNNe @ kyba @ Serial 1802
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