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Smith MA, Waugh DA, McBurney DL, George JC, Suydam RS, Thewissen JGM, Crish SD. A comparative analysis of cone photoreceptor morphology in bowhead and beluga whales. J Comp Neurol 2020; 529:2376-2390. [PMID: 33377221 DOI: 10.1002/cne.25101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/30/2022]
Abstract
The cetacean visual system is a product of selection pressures favoring underwater vision, yet relatively little is known about it across taxa. Previous studies report several mutations in the opsin genetic sequence in cetaceans, suggesting the evolutionary complete or partial loss of retinal cone photoreceptor function in mysticete and odontocete lineages, respectively. Despite this, limited anatomical evidence suggests cone structures are partially maintained but with absent outer and inner segments in the bowhead retina. The functional consequence and anatomical distributions associated with these unique cone morphologies remain unclear. The current study further investigates the morphology and distribution of cone photoreceptors in the bowhead whale and beluga retina and evaluates the potential functional capacity of these cells' alternative to photoreception. Refined histological and advanced microscopic techniques revealed two additional cone morphologies in the bowhead and beluga retina that have not been previously described. Two proteins involved in magnetosensation were present in these cone structures suggesting the possibility for an alternative functional role in responding to changes in geomagnetic fields. These findings highlight a revised understanding of the unique evolution of cone and gross retinal anatomy in cetaceans, and provide prefatory evidence of potential functional reassignment of these cells.
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Affiliation(s)
- Matthew A Smith
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA.,Rebecca D. Considine Research Institute, Akron Children's Hospital, Akron, Ohio, USA
| | - David A Waugh
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Denise L McBurney
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - John C George
- Department of Wildlife Management, North Slope Borough, Utqiagvik, Alaska, USA
| | - Robert S Suydam
- Department of Wildlife Management, North Slope Borough, Utqiagvik, Alaska, USA
| | - Johannes G M Thewissen
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Samuel D Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
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Peel LR, Collin SP, Hart NS. Retinal topography and spectral sensitivity of the Port Jackson shark (
Heterodontus portusjacksoni
). J Comp Neurol 2020; 528:2831-2847. [DOI: 10.1002/cne.24911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/20/2020] [Accepted: 03/20/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Lauren R. Peel
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- The Oceans Institute University of Western Australia Crawley Western Australia Australia
- The Oceans Graduate School University of Western Australia Crawley Western Australia Australia
| | - Shaun P. Collin
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- The Oceans Institute University of Western Australia Crawley Western Australia Australia
- The Oceans Graduate School University of Western Australia Crawley Western Australia Australia
- School of Life Sciences, La Trobe University Bundoora Victoria Australia
| | - Nathan S. Hart
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Department of Biological Sciences Macquarie University Sydney New South Wales Australia
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Jinson ST, Liebich J, Senft SL, Mäthger LM. Retinal specializations and visual ecology in an animal with an extremely elaborate pupil shape: the little skate Leucoraja (Raja) erinacea Mitchell, 1825. J Comp Neurol 2018; 526:1962-1977. [PMID: 29756297 DOI: 10.1002/cne.24465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 11/11/2022]
Abstract
Investigating retinal specializations offers insights into eye functionality. Using retinal wholemount techniques, we investigated the distribution of retinal ganglion cells in the Little skate Leucoraja erinacea by (a) dye-backfilling into the optic nerve prior to retinal wholemounting; (b) Nissl-staining of retinal wholemounts. Retinas were examined for regional specializations (higher numbers) of ganglion cells that would indicate higher visual acuity in those areas. Total ganglion cell number were low compared to other elasmobranchs (backfilled: average 49,713 total ganglion cells, average peak cell density 1,315 ganglion cells mm-2 ; Nissl-stained: average 47,791 total ganglion cells, average peak cell density 1,319 ganglion cells mm-2 ). Ganglion cells fit into three size categories: small (5-20 µm); medium (20-30 µm); large: (≥ 30 µm), and they were not homogeneously distributed across the retina. There was a dorsally located horizontal visual streak with increased ganglion cell density; additionally, there were approximately three local maxima in ganglion cell distribution (potential areae centrales) within this streak in which densities were highest. Using computerized tomography (CT) and micro-CT, geometrical dimensions of the eye were obtained. Combined with ganglion cell distributions, spatial resolving power was determined to be between 1.21 and 1.37 cycles per degree. Additionally, photoreceptor sizes across different retinal areas varied; photoreceptors were longest within the horizontal visual streak. Variations in the locations of retinal specializations appear to be related to the animal's anatomy: shape of the head and eyes, position of eyes, location of tapetum, and shape of pupil, as well as the visual demands associated with lifestyle and habitat type.
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Affiliation(s)
- S Terrell Jinson
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, Massachusetts
| | - Jan Liebich
- Westphalian Institute for Biomimetics, Westphalian University of Applied Sciences, Bocholt, Germany
| | - Stephen L Senft
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, Massachusetts
| | - Lydia M Mäthger
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, Massachusetts
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Collin SP. Scene through the eyes of an apex predator: a comparative analysis of the shark visual system. Clin Exp Optom 2018; 101:624-640. [PMID: 30066959 DOI: 10.1111/cxo.12823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/09/2018] [Accepted: 07/09/2018] [Indexed: 12/15/2022] Open
Abstract
The eyes of apex predators, such as the shark, have fascinated comparative visual neuroscientists for hundreds of years with respect to how they perceive the dark depths of their ocean realm or the visual scene in search of prey. As the earliest representatives of the first stage in the evolution of jawed vertebrates, sharks have an important role to play in our understanding of the evolution of the vertebrate eye, including that of humans. This comprehensive review covers the structure and function of all the major ocular components in sharks and how they are adapted to a range of underwater light environments. A comparative approach is used to identify: species-specific diversity in the perception of clear optical images; photoreception for various visual behaviours; the trade-off between image resolution and sensitivity; and visual processing under a range of levels of illumination. The application of this knowledge is also discussed with respect to the conservation of this important group of cartilaginous fishes.
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Affiliation(s)
- Shaun P Collin
- The Oceans Institute and the Oceans Graduate School, The University of Western Australia, Perth, Western Australia, Australia
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5
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Long Y, Zhang R, Huang J, Wang J, Zhang J, Rayand N, Hu GH, Yang J, Zhu J. Retroreflection in binary bio-based PLA/PBF blends. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Coimbra JP, Kaswera-Kyamakya C, Gilissen E, Manger PR, Collin SP. The Retina of Ansorge's Cusimanse (Crossarchus ansorgei): Number, Topography and Convergence of Photoreceptors and Ganglion Cells in Relation to Ecology and Behavior. BRAIN, BEHAVIOR AND EVOLUTION 2015; 86:79-93. [DOI: 10.1159/000433514] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/22/2015] [Indexed: 11/19/2022]
Abstract
The family Herpestidae (cusimanses and mongooses) is a monophyletic radiation of carnivores with remarkable variation in microhabitat occupation and diel activity, but virtually nothing is known about how they use vision in the context of their behavioral ecology. In this paper, we measured the number and topographic distribution of neurons (rods, cones and retinal ganglion cells) and estimated the spatial resolving power of the eye of the diurnal, forest-dwelling Ansorge's cusimanse (Crossarchus ansorgei). Using retinal wholemounts and stereology, we found that rods are more numerous (42,500,000; 92%) than cones (3,900,000; 8%). Rod densities form a concentric and dorsotemporally asymmetric plateau that matches the location and shape of a bright yellow tapetum lucidum located within the dorsal aspect of the eye. Maximum rod density (340,300 cells/mm2) occurs within an elongated plateau below the optic disc that corresponds to a transitional region between the tapetum lucidum and the pigmented choroid. Cone densities form a temporal area with a peak density of 44,500 cells/mm2 embedded in a weak horizontal streak that matches the topographic distribution of retinal ganglion cells. Convergence ratios of cones to retinal ganglion cells vary from 50:1 in the far periphery to 3:1 in the temporal area. With a ganglion cell peak density of 13,400 cells/mm2 and an eye size of 11 mm in axial length, we estimated upper limits of spatial resolution of 7.5-8 cycles/degree, which is comparable to other carnivores such as hyenas. In conclusion, we suggest that the topographic retinal traits described for Ansorge's cusimanse conform to a presumed carnivore retinal blueprint but also show variations that reflect its specific ecological needs.
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Cohn BA, Collin SP, Wainwright PC, Schmitz L. Retinal topography maps in R: new tools for the analysis and visualization of spatial retinal data. J Vis 2015; 15:19. [PMID: 26230981 PMCID: PMC4527213 DOI: 10.1167/15.9.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 06/03/2015] [Indexed: 12/29/2022] Open
Abstract
Retinal topography maps are a widely used tool in vision science, neuroscience, and visual ecology, providing an informative visualization of the spatial distribution of cell densities across the retinal hemisphere. Here, we introduce Retina, an R package for computational mapping, inspection of topographic model fits, and generation of average maps. Functions in Retina take cell count data obtained from retinal wholemounts using stereology software. Accurate visualizations and comparisons between different eyes have been difficult in the past, because of deformation and incisions of retinal wholemounts. We account for these issues by incorporation of the R package Retistruct, which results in a retrodeformation of the wholemount into a hemispherical shape, similar to the original eyecup. The maps are generated by thin plate splines, after the data were transformed into a two-dimensional space with an azimuthal equidistant plot projection. Retina users can compute retinal topography maps independent of stereology software choice and assess model fits with a variety of diagnostic plots. Functionality of Retina also includes species average maps, an essential feature for interspecific analyses. The Retina package will facilitate rigorous comparative studies in visual ecology by providing a robust quantitative approach to generate retinal topography maps.
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Spectral sensitivity, luminous sensitivity, and temporal resolution of the visual systems in three sympatric temperate coastal shark species. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:997-1013. [DOI: 10.1007/s00359-014-0950-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 09/23/2014] [Accepted: 10/01/2014] [Indexed: 01/04/2023]
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Claes JM, Partridge JC, Hart NS, Garza-Gisholt E, Ho HC, Mallefet J, Collin SP. Photon hunting in the twilight zone: visual features of mesopelagic bioluminescent sharks. PLoS One 2014; 9:e104213. [PMID: 25099504 PMCID: PMC4123902 DOI: 10.1371/journal.pone.0104213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/04/2014] [Indexed: 01/01/2023] Open
Abstract
The mesopelagic zone is a visual scene continuum in which organisms have developed various strategies to optimize photon capture. Here, we used light microscopy, stereology-assisted retinal topographic mapping, spectrophotometry and microspectrophotometry to investigate the visual ecology of deep-sea bioluminescent sharks [four etmopterid species (Etmopterus lucifer, E. splendidus, E. spinax and Trigonognathus kabeyai) and one dalatiid species (Squaliolus aliae)]. We highlighted a novel structure, a translucent area present in the upper eye orbit of Etmopteridae, which might be part of a reference system for counterillumination adjustment or acts as a spectral filter for camouflage breaking, as well as several ocular specialisations such as aphakic gaps and semicircular tapeta previously unknown in elasmobranchs. All species showed pure rod hexagonal mosaics with a high topographic diversity. Retinal specialisations, formed by shallow cell density gradients, may aid in prey detection and reflect lifestyle differences; pelagic species display areae centrales while benthopelagic and benthic species display wide and narrow horizontal streaks, respectively. One species (E. lucifer) displays two areae within its horizontal streak that likely allows detection of conspecifics' elongated bioluminescent flank markings. Ganglion cell topography reveals less variation with all species showing a temporal area for acute frontal binocular vision. This area is dorsally extended in T. kabeyai, allowing this species to adjust the strike of its peculiar jaws in the ventro-frontal visual field. Etmopterus lucifer showed an additional nasal area matching a high rod density area. Peak spectral sensitivities of the rod visual pigments (λmax) fall within the range 484–491 nm, allowing these sharks to detect a high proportion of photons present in their habitat. Comparisons with previously published data reveal ocular differences between bioluminescent and non-bioluminescent deep-sea sharks. In particular, bioluminescent sharks possess higher rod densities, which might provide them with improved temporal resolution particularly useful for bioluminescent communication during social interactions.
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Affiliation(s)
- Julien M. Claes
- Laboratoire de Biologie Marine, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- * E-mail:
| | - Julian C. Partridge
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- Neuroecology Group, School of Animal Biology and the UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Nathan S. Hart
- Neuroecology Group, School of Animal Biology and the UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Eduardo Garza-Gisholt
- Neuroecology Group, School of Animal Biology and the UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Hsuan-Ching Ho
- National Museum of Marine Biology and Aquarium, Checheng, Taiwan
- Institute of Marine Biodiversity and Evolutionary Biology, National Dong Hwa University, Shoufeng, Taiwan
| | - Jérôme Mallefet
- Laboratoire de Biologie Marine, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Shaun P. Collin
- Neuroecology Group, School of Animal Biology and the UWA Oceans Institute, The University of Western Australia, Crawley, Australia
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