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Warrant EJ. A formative journal for a formative career: a personal recollection of how JCPA has inspired and guided my research life. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:203-210. [PMID: 38082048 PMCID: PMC10994867 DOI: 10.1007/s00359-023-01683-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 11/11/2023] [Accepted: 11/14/2023] [Indexed: 04/05/2024]
Abstract
A fateful decision as a 15-year-old high school student, and good advice from a distinguished professor of zoology, were the catalysts that not only decided my entire career but also led me to the Journal of Comparative Physiology A, and to the myriad biological wonders that were held within its covers. In my celebration of JCPA, I look back on the formative years of my career in Australia, and the crucial role that the journal played in shaping my emerging research interests, and ultimately my entire life.
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Affiliation(s)
- Eric J Warrant
- Lund Vision Group, Department of Biology, University of Lund, Sölvegatan 35, 22362, Lund, Sweden.
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2
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Andronache I, Peptenatu D, Ahammer H, Radulovic M, Djuričić GJ, Jelinek HF, Russo C, Di Ieva A. Fractals in the Neurosciences: A Translational Geographical Approach. ADVANCES IN NEUROBIOLOGY 2024; 36:953-981. [PMID: 38468071 DOI: 10.1007/978-3-031-47606-8_47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
The chapter presents three new fractal indices (fractal fragmentation index, fractal tentacularity index, and fractal anisotropy index) and normalized Kolmogorov complexity with proven applicability in geographic research, developed by the authors, and the possibility of their future use in neuroscience. The research demonstrates the relevance of fractal analysis in different fields and the basic concepts and principles of fractal geometry being sufficient for the development of models relevant to the studied reality. Also, the research highlighted the need to continue interdisciplinary research based on known fractal indicators, as well as the development of new analysis methods with the translational potential between fields.
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Affiliation(s)
- Ion Andronache
- Research Center for Integrated Analysis and Territorial Management, Faculty of Geography, University of Bucharest, Bucharest, Romania.
| | - Daniel Peptenatu
- Research Center for Integrated Analysis and Territorial Management, Faculty of Geography, University of Bucharest, Bucharest, Romania
| | - Helmut Ahammer
- GSRC, Division of Medical Physics and Biophysics, Medical University of Graz, Graz, Austria
| | - Marko Radulovic
- Department of Experimental Oncology, Institute of Oncology and Radiology of Serbia, Belgrade, Serbia
| | - Goran J Djuričić
- Department of Radiology, Faculty of Medicine, University of Belgrade, University Children's Hospital, Belgrade, Serbia
| | - Herbert F Jelinek
- Department of Medical Sciences and Biotechnology Center, Khalifa University, Abu Dhabi, UAE
| | - Carlo Russo
- Computational NeuroSurgery (CNS) Lab, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Antonio Di Ieva
- Computational NeuroSurgery (CNS) Lab, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
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3
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Fogg LG, Chung WS, Justin Marshall N, Cortesi F, de Busserolles F. Multiple rod layers increase the speed and sensitivity of vision in nocturnal reef fishes. Proc Biol Sci 2023; 290:20231749. [PMID: 37989239 PMCID: PMC10688437 DOI: 10.1098/rspb.2023.1749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/24/2023] [Indexed: 11/23/2023] Open
Abstract
Most vertebrates have one layer of the dim-light active rod photoreceptors. However, multiple rod layers, known as a multibank retina, can be found in over 100 species of fish, including several deep-sea species and one family of nocturnally active reef fish, the Holocentridae. Although seemingly associated with increased photon catch, the function of multibank retinas remained unknown. We used an integrative approach, combining histology, electrophysiology and amino acid sequence analysis, applied to three species of nocturnal reef fishes, two holocentrids with a multibank retina (Neoniphon sammara and Myripristis violacea) and an apogonid with a single rod bank (Ostorhinchus compressus), to determine the sensory advantage of multiple rod layers. Our results showed that fish with multibank retinas have both faster vision and enhanced responses to bright- and dim-light intensities. Faster vision was indicated by higher flicker fusion frequencies during temporal resolution electroretinography as well as faster retinal release rates estimated from their rhodopsin proteins. Enhanced sensitivity was demonstrated by broadened intensity-response curves derived from luminous sensitivity electroretinography. Overall, our findings provide the first functional evidence for enhanced dim-light sensitivity using a multibank retina while also suggesting novel roles for the adaptation in enhancing bright-light sensitivity and the speed of vision.
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Affiliation(s)
- Lily G. Fogg
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Wen-Sung Chung
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - N. Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Fabio Cortesi
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
- School of the Environment, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Fanny de Busserolles
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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4
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Reading JGJ, Horton T. Mesopelagic fishes of the North-West African Upwelling from the Discovery Collections. Biodivers Data J 2023; 11:e105921. [PMID: 38318511 PMCID: PMC10840843 DOI: 10.3897/bdj.11.e105921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/03/2023] [Indexed: 02/07/2024] Open
Abstract
Background Mesopelagic fish specimens from two stations in the NW African Upwelling were identified and catalogued to produce a Darwin Core-aligned dataset. A total of 9655 individual fishes were identified, with 9017 specimens identified at least to genus level and 3124 specimens identified to species level. This dataset comprises specimens collected from the 1990 RRS Discovery (III) Cruise D195 and was used to investigate depth-related trends in diversity and community composition alongside species-specific migratory behaviour. The finalised dataset was published on OBIS through the Deep-Sea node. New information This dataset contains occurrence and abundance data for midwater fishes caught between the Mauritanian coast and Cape Verde, published for the first time. The dataset records 146 different fish taxa. Twenty-three taxa in the dataset are not present in any prior OBIS datasets that cover the area. These novel taxa are: Bathylagusandriashevi, Bolinichthysindicus, Bolinichthyssupralateralis, Cyclothoneparapallida, Dolichopteroidesbinocularis, Gigantactis indet. Gymnoscopelus stet., Howellaatlantica, Hygophumproximum, Hygophumtaaningi, Ichthyococcuspolli, Lampadenaanomala, Lampanyctuscuprarius, Lampanyctusisaacsi, Lampanyctuslineatus, Lampanyctusmacdonaldi, Lampanyctusnobilis, Lestidiopsmirabilis, Loweinarara, Macroparalepisbrevis, Melamphaesmicrops and Melanonusgracilis. An anglerfish specimen belonging to Linophrynidae was also found, the first in the leftvent family to be logged in the area on OBIS; however, the specimen was too damaged to identify beyond this level.
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Affiliation(s)
- Jethro George Jack Reading
- University of Southampton, Southampton, United KingdomUniversity of SouthamptonSouthamptonUnited Kingdom
| | - Tammy Horton
- National Oceanography Centre, Southampton, United KingdomNational Oceanography CentreSouthamptonUnited Kingdom
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5
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Wagner HJ, Genner MJ, Partridge JC, Chung WS, Marshall NJ, Robison BH, Douglas RH. Diversity and evolution of optically complex eyes in a family of deep-sea fish: Ocular diverticula in barreleye spookfish (Opisthoproctidae). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1044565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Several families of mesopelagic fish have tubular eyes that are usually upwardly directed. These maximise sensitivity to dim downwelling sunlight and dorsal bioluminescence, as well as facilitating the detection of dark silhouettes above the animal. Such eyes, however, have a much-reduced field of view and will not be sensitive to, for example, lateral and ventral bioluminescent stimuli. All mesopelagic Opisthoproctidae so far examined have evolved mechanisms for extending the limited visual field of their eyes using approximately ventrolaterally directed, light-sensitive, diverticula. Some genera have small rudimentary lateral retinal areas capable of detecting only unfocussed illumination. Others have more extensive structures resulting in eyes that simultaneously focus light from above onto the main retina of the tubular eye using a lens, while diverticula produce focussed images of ventrolateral illumination using either reflection or possibly refraction. These bipartite structures represent perhaps the most optically complex of all vertebrate eyes. Here we extend the limited previous data on the ocular morphology of five Opisthoproctidae (Opisthoproctus soleatus, Winteria telescopa, Dolichopteryx longipes, Rhynchohyalus natalensis, and Bathylychnops exilis) using a combination of histology and magnetic resonance imaging and provide a preliminary description of the eyes of Macropinna microstoma. We note an increase in diverticular complexity over the life span of some species and quantify the contribution of the diverticulum to the eye’s total neural output in D. longipes and R. natalensis (25 and 20%, respectively). To help understand the evolution of Opisthoproctidae ocular diversity, a phylogeny, including all the species whose eye types are known, was reconstructed using DNA sequences from 15 mitochondrial and four nuclear genes. Mapping the different types of diverticula onto this phylogeny suggests a process of repeated evolution of complex ocular morphology from more rudimentary diverticula.
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Fukuda N, Yamamoto T, Yokouchi K, Kurogi H, Okazaki M, Miyake Y, Watanabe T, Chow S. Active swimming and transphort by currents observed in Japanese eels (Anguilla japonica) acoustically tracked in the western North Pacific. Sci Rep 2022; 12:3490. [PMID: 35232985 PMCID: PMC8888653 DOI: 10.1038/s41598-022-05880-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 01/12/2022] [Indexed: 11/15/2022] Open
Abstract
The mechanisms of oceanic animal migration remain enigmatic. Adult Japanese eels start their long-distance oceanic migration from coastal areas to breed near the West Mariana Ridge. We tracked acoustically tagged eels released in the Kuroshio Current (KC) area near Japan (five silver-phase eels, three of which had impaired swim bladders) and a tropical/subtropical (TS) area near/in the spawning area (two yellow-phase and three silver-phase eels). We analyzed their active swimming and transport by water currents. The strong flow of the KC dominated the eels’ movements in the north, and TS area; their swimming influenced their movements. In the KC area, greater distances were covered at night than during the day, because eels swam in shallower layers with strong currents at night. Three and one eel in the TS and KC area in the upper 400 m showed counterclockwise and clockwise movements around the time of solar culmination, respectively. The meta-analysis showed that eels released at middle latitudes (20°–34° N) generally swam southward through currents, whereas those released at low latitudes (12°–13° N) generally swam northward through currents. Our study suggests the influence of the surrounding current and a potential effect of solar cues on the movements of Japanese eels.
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Affiliation(s)
- Nobuto Fukuda
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan.
| | - Toshihiro Yamamoto
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Kazuki Yokouchi
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Hiroaki Kurogi
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Makoto Okazaki
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Yoichi Miyake
- Japan Fisheries Research and Education Agency, Hatsukaichi Station2-17-5 Maruishi, Hatsukaichi, Hiroshima, 739-0452, Japan
| | - Tomowo Watanabe
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Seinen Chow
- Japan Fisheries Research and Education Agency, Yokohama Station2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
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7
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Dong EM, Allison WT. Vertebrate features revealed in the rudimentary eye of the Pacific hagfish ( Eptatretus stoutii). Proc Biol Sci 2021; 288:20202187. [PMID: 33434464 DOI: 10.1098/rspb.2020.2187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hagfish eyes are markedly basic compared to the eyes of other vertebrates, lacking a pigmented epithelium, a lens and a retinal architecture built of three cell layers: the photoreceptors, interneurons and ganglion cells. Concomitant with hagfish belonging to the earliest-branching vertebrate group (the jawless Agnathans), this lack of derived characters has prompted competing interpretations that hagfish eyes represent either a transitional form in the early evolution of vertebrate vision, or a regression from a previously elaborate organ. Here, we show the hagfish retina is not extensively degenerating during its ontogeny, but instead grows throughout life via a recognizable PAX6+ ciliary marginal zone. The retina has a distinct layer of photoreceptor cells that appear to homogeneously express a single opsin of the RH1 rod opsin class. The epithelium that encompasses these photoreceptors is striking because it lacks the melanin pigment that is universally associated with animal vision; notwithstanding, we suggest this epithelium is a homologue of gnathosome retinal pigment epithelium (RPE) based on its robust expression of RPE65 and its engulfment of photoreceptor outer segments. We infer that the hagfish retina is not entirely rudimentary in its wiring, despite lacking a morphologically distinct layer of interneurons: multiple populations of cells exist in the hagfish inner retina and subsets of these express markers of vertebrate retinal interneurons. Overall, these data clarify Agnathan retinal homologies, reveal characters that now appear to be ubiquitous across the eyes of vertebrates, and refine interpretations of early vertebrate visual system evolution.
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Affiliation(s)
- Emily M Dong
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T7Y 1C4
| | - W Ted Allison
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T7Y 1C4
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8
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de Busserolles F, Fogg L, Cortesi F, Marshall J. The exceptional diversity of visual adaptations in deep-sea teleost fishes. Semin Cell Dev Biol 2020; 106:20-30. [PMID: 32536437 DOI: 10.1016/j.semcdb.2020.05.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/28/2020] [Accepted: 05/28/2020] [Indexed: 10/24/2022]
Abstract
The deep-sea is the largest and one of the dimmest habitats on earth. In this extreme environment, every photon counts and may make the difference between life and death for its inhabitants. Two sources of light are present in the deep-sea; downwelling light, that becomes dimmer and spectrally narrower with increasing depth until completely disappearing at around 1000 m, and bioluminescence, the light emitted by animals themselves. Despite these relatively dark and inhospitable conditions, many teleost fish have made the deep-sea their home, relying heavily on vision to survive. Their visual systems have had to adapt, sometimes in astonishing and bizarre ways. This review examines some aspects of the visual system of deep-sea teleosts and highlights the exceptional diversity in both optical and retinal specialisations. We also reveal how widespread several of these adaptations are across the deep-sea teleost phylogeny. Finally, the significance of some recent findings as well as the surprising diversity in visual adaptations is discussed.
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Affiliation(s)
- Fanny de Busserolles
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia.
| | - Lily Fogg
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Fabio Cortesi
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Justin Marshall
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
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9
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Davis AL, Sutton TT, Kier WM, Johnsen S. Evidence that eye-facing photophores serve as a reference for counterillumination in an order of deep-sea fishes. Proc Biol Sci 2020; 287:20192918. [PMID: 32517614 DOI: 10.1098/rspb.2019.2918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Counterillumination, the masking of an animal's silhouette with ventral photophores, is found in a number of mesopelagic taxa but is difficult to employ because it requires that the animal match the intensity of downwelling light without seeing its own ventral photophores. It has been proposed that the myctophid, Tarletonbeania crenularis, uses a photophore directed towards the eye, termed an eye-facing photophore, as a reference standard that it adjusts to match downwelling light. The potential use of this mechanism, however, has not been evaluated in other fishes. Here, we use micro-computed tomography, photography and dissection to evaluate the presence/absence of eye-facing photophores in three families of stomiiform fishes. We found that all sampled species with ventral photophores capable of counterillumination possess an eye-facing photophore that is pigmented on the anterior and lateral sides, thus preventing its use as a laterally directed signal, lure or searchlight. The two species that are incapable of counterillumination, Cyclothone obscura and Sigmops bathyphilus, lack an eye-facing photophore. After determining the phylogenetic distribution of eye-facing photophores, we used histology to examine the morphology of the cranial tissue in Argyropelecus aculeatus and determined that light from the eye-facing photophore passes through a transparent layer of tissue, then the lens, and finally strikes the accessory retina. Additionally, eight of the 14 species for which fresh specimens were available had an aphakic gap that aligned with the path of emitted light from the eye-facing photophore, while the remaining six had no aphakic gap. These findings, combined with records of eye-facing photophores from distantly related taxa, strongly suggest that eye-facing photophores serve as a reference for counterillumination in these fishes.
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Affiliation(s)
| | - Tracey T Sutton
- Department of Marine and Environmental Sciences, Nova Southeastern University, Dania Beach, FL 33004, USA
| | - William M Kier
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Sönke Johnsen
- Department of Biology, Duke University, Durham, NC 27708, USA
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10
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Observations on the retina and ‘optical fold’ of a mesopelagic sabretooth fish, Evermanella balbo. Cell Tissue Res 2019; 378:411-425. [DOI: 10.1007/s00441-019-03060-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/16/2019] [Indexed: 11/26/2022]
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11
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Fritsch R, Collin SP, Michiels NK. Anatomical Analysis of the Retinal Specializations to a Crypto-Benthic, Micro-Predatory Lifestyle in the Mediterranean Triplefin Blenny Tripterygion delaisi. Front Neuroanat 2017; 11:122. [PMID: 29311852 PMCID: PMC5732991 DOI: 10.3389/fnana.2017.00122] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/28/2017] [Indexed: 12/27/2022] Open
Abstract
The environment and lifestyle of a species are known to exert selective pressure on the visual system, often demonstrating a tight link between visual morphology and ecology. Many studies have predicted the visual requirements of a species by examining the anatomical features of the eye. However, among the vast number of studies on visual specializations in aquatic animals, only a few have focused on small benthic fishes that occupy a heterogeneous and spatially complex visual environment. This study investigates the general retinal anatomy including the topography of both the photoreceptor and ganglion cell populations and estimates the spatial resolving power (SRP) of the eye of the Mediterranean triplefin Tripterygion delaisi. Retinal wholemounts were prepared to systematically and quantitatively analyze photoreceptor and retinal ganglion cell (RGC) densities using design-based stereology. To further examine the retinal structure, we also used magnetic resonance imaging (MRI) and histological examination of retinal cross sections. Observations of the triplefin's eyes revealed them to be highly mobile, allowing them to view the surroundings without body movements. A rostral aphakic gap and the elliptical shape of the eye extend its visual field rostrally and allow for a rostro-caudal accommodatory axis, enabling this species to focus on prey at close range. Single and twin cones dominate the retina and are consistently arranged in one of two regular patterns, which may enhance motion detection and color vision. The retina features a prominent, dorso-temporal, convexiclivate fovea with an average density of 104,400 double and 30,800 single cones per mm2, and 81,000 RGCs per mm2. Based on photoreceptor spacing, SRP was calculated to be between 6.7 and 9.0 cycles per degree. Location and resolving power of the fovea would benefit the detection and identification of small prey in the lower frontal region of the visual field.
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Affiliation(s)
- Roland Fritsch
- Animal Evolutionary Ecology, Department of Biology, Institute of Evolution and Ecology, University of Tübingen, Tübingen, Germany
| | - Shaun P. Collin
- The Oceans Institute, The University of Western Australia, Crawley, WA, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Nico K. Michiels
- Animal Evolutionary Ecology, Department of Biology, Institute of Evolution and Ecology, University of Tübingen, Tübingen, Germany
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de Busserolles F, Marshall NJ. Seeing in the deep-sea: visual adaptations in lanternfishes. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0070. [PMID: 28193815 DOI: 10.1098/rstb.2016.0070] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2016] [Indexed: 11/12/2022] Open
Abstract
Ecological and behavioural constraints play a major role in shaping the visual system of different organisms. In the mesopelagic zone of the deep- sea, between 200 and 1000 m, very low intensities of downwelling light remain, creating one of the dimmest habitats in the world. This ambient light is, however, enhanced by a multitude of bioluminescent signals emitted by its inhabitants, but these are generally dim and intermittent. As a result, the visual system of mesopelagic organisms has been pushed to its sensitivity limits in order to function in this extreme environment. This review covers the current body of knowledge on the visual system of one of the most abundant and intensely studied groups of mesopelagic fishes: the lanternfish (Myctophidae). We discuss how the plasticity, performance and novelty of its visual adaptations, compared with other deep-sea fishes, might have contributed to the diversity and abundance of this family.This article is part of the themed issue 'Vision in dim light'.
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Affiliation(s)
- Fanny de Busserolles
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - N Justin Marshall
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
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13
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García M, Tomás S, Robles ML, Ramos A, Segovia Y. Morphology of the retina in deep-water fish Nezumia sclerorhynchus
(Valenciennes, 1838) (Gadiformes: Macrouridae). ACTA ZOOL-STOCKHOLM 2017. [DOI: 10.1111/azo.12194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Magdalena García
- Department of Biotechnology; University of Alicante; Alicante Spain
| | - Sabina Tomás
- Department of Biotechnology; University of Alicante; Alicante Spain
| | | | - Alfonso Ramos
- Department of Marine Sciences and Applied Biology; University of Alicante; Alicante Spain
| | - Yolanda Segovia
- Department of Biotechnology; University of Alicante; Alicante Spain
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14
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Poulsen JY, Sado T, Hahn C, Byrkjedal I, Moku M, Miya M. Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes). PLoS One 2016; 11:e0159762. [PMID: 27508419 PMCID: PMC4980007 DOI: 10.1371/journal.pone.0159762] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 07/06/2016] [Indexed: 11/18/2022] Open
Abstract
The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations. All the species in the family are united by the possession of tubular eyes, with one distinct lineage exhibiting also drastic shortening of the body. Two new species of the mesopelagic opisthoproctid mirrorbelly genus Monacoa are described based on pigmentation patterns of the "sole"-a unique vertebrate structure used in the reflection and control of bioluminescence in most short-bodied forms. Different pigmentation patterns of the soles, previously noted as intraspecific variations based on preserved specimens, are here shown species-specific and likely used for communication in addition to counter-illumination of down-welling sunlight. The genus Monacoa is resurrected from Opisthoproctus based on extensive morphological synaphomorphies pertaining to the anal fin and snout. Doubling the species diversity within sole-bearing opisthoproctids, including recognition of two genera, is unambiguously supported by mitogenomic DNA sequence data. Regular fixation with formalin and alcohol preservation is shown problematic concerning the retention of species-specific pigmentation patterns. Examination or photos of fresh material before formalin fixation is shown paramount for correct species recognition of sole-bearing opisthoproctids-a relatively unknown issue concerning species diversity in the deep-sea pelagic realm.
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Affiliation(s)
- Jan Yde Poulsen
- Fish Section, Australian Museum, Sydney NSW, Australia
- Department of Fish and Shellfish, Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Tetsuya Sado
- Natural History Museum and Institute, 955-2 Aoba-cho, Chuo-ku, Chiba, Japan
| | - Christoph Hahn
- School for Biological, Biomedical and Environmental Science, University of Hull, Hull, United Kingdom
| | - Ingvar Byrkjedal
- Natural History Collections, Bergen Museum, University of Bergen, Bergen, Norway
| | - Masatoshi Moku
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwano-Ha, Kashiwa, Chiba, Japan
| | - Masaki Miya
- Natural History Museum and Institute, 955-2 Aoba-cho, Chuo-ku, Chiba, Japan
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15
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Biagioni LM, Hunt DM, Collin SP. Morphological Characterization and Topographic Analysis of Multiple Photoreceptor Types in the Retinae of Mesopelagic Hatchetfishes with Tubular Eyes. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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de Busserolles F, Marshall NJ, Collin SP. Retinal Ganglion Cell Distribution and Spatial Resolving Power in Deep-Sea Lanternfishes (Myctophidae). BRAIN, BEHAVIOR AND EVOLUTION 2014; 84:262-76. [DOI: 10.1159/000365960] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/16/2014] [Indexed: 11/19/2022]
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Partridge JC, Douglas RH, Marshall NJ, Chung WS, Jordan TM, Wagner HJ. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis). Proc Biol Sci 2014; 281:20133223. [PMID: 24648222 PMCID: PMC3973263 DOI: 10.1098/rspb.2013.3223] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics.
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Affiliation(s)
- J C Partridge
- School of Biological Sciences, University of Bristol, , Woodland Road, Bristol BS8 1UG, UK, Department of Optometry and Visual Science, City University London, , Northampton Square, London EC1V 0HB, UK, Queensland Brain Institute, University of Queensland, , St Lucia, Brisbane, Queensland 4072, Australia, Anatomisches Institut, Universität Tübingen, , Ősterbergstrasse 3, Tübingen 72074, Germany, School of Animal Biology, University of Western Australia, , 35 Stirling Highway, Crawley, Perth, Western Australia 6009, Australia
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Landgren E, Fritsches K, Brill R, Warrant E. The visual ecology of a deep-sea fish, the escolar Lepidocybium flavobrunneum (Smith, 1843). Philos Trans R Soc Lond B Biol Sci 2014; 369:20130039. [PMID: 24395966 DOI: 10.1098/rstb.2013.0039] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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°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.
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Affiliation(s)
- Eva Landgren
- Lund Vision Group, Department of Biology, University of Lund, , Sölvegatan 35, 22362 Lund, Sweden
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Visual acuity in pelagic fishes and mollusks. Vision Res 2013; 92:1-9. [DOI: 10.1016/j.visres.2013.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/13/2013] [Accepted: 08/16/2013] [Indexed: 11/20/2022]
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de Busserolles F, Fitzpatrick JL, Paxton JR, Marshall NJ, Collin SP. Eye-size variability in deep-sea lanternfishes (Myctophidae): an ecological and phylogenetic study. PLoS One 2013; 8:e58519. [PMID: 23472203 PMCID: PMC3589346 DOI: 10.1371/journal.pone.0058519] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/05/2013] [Indexed: 11/30/2022] Open
Abstract
One of the most common visual adaptations seen in the mesopelagic zone (200–1000 m), where the amount of light diminishes exponentially with depth and where bioluminescent organisms predominate, is the enlargement of the eye and pupil area. However, it remains unclear how eye size is influenced by depth, other environmental conditions and phylogeny. In this study, we determine the factors influencing variability in eye size and assess whether this variability is explained by ecological differences in habitat and lifestyle within a family of mesopelagic fishes characterized by broad intra- and interspecific variance in depth range and luminous patterns. We focus our study on the lanternfish family (Myctophidae) and hypothesise that lanternfishes with a deeper distribution and/or a reduction of bioluminescent emissions have smaller eyes and that ecological factors rather than phylogenetic relationships will drive the evolution of the visual system. Eye diameter and standard length were measured in 237 individuals from 61 species of lanternfishes representing all the recognised tribes within the family in addition to compiling an ecological dataset including depth distribution during night and day and the location and sexual dimorphism of luminous organs. Hypotheses were tested by investigating the relationship between the relative size of the eye (corrected for body size) and variations in depth and/or patterns of luminous-organs using phylogenetic comparative analyses. Results show a great variability in relative eye size within the Myctophidae at all taxonomic levels (from subfamily to genus), suggesting that this character may have evolved several times. However, variability in eye size within the family could not be explained by any of our ecological variables (bioluminescence and depth patterns), and appears to be driven solely by phylogenetic relationships.
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Affiliation(s)
- Fanny de Busserolles
- Neuroecology Group, School of Animal Biology and the Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia.
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Speiser DI, Loew ER, Johnsen S. Spectral sensitivity of the concave mirror eyes of scallops: potential influences of habitat, self-screening and longitudinal chromatic aberration. J Exp Biol 2011; 214:422-31. [DOI: 10.1242/jeb.048108] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Scallop eyes contain two retinas, one proximal and one distal. Molecular evidence suggests that each retina expresses a different visual pigment. To test whether these retinas have different spectral sensitivities, we used microspectrophotometry to measure the absorption spectra of photoreceptors from the eyes of two different scallop species. Photoreceptors from the proximal and distal retinas of the sea scallop Placopecten magellanicus had absorption peak wavelengths (λmax) of 488±1 nm (mean ± s.e.m.; N=20) and 513±3 nm (N=26), respectively. Photoreceptors from the corresponding retinas of the bay scallop Argopecten irradians had λmax values of 506±1 nm (N=21) and 535±3 nm (N=14). Assuming that the proximal and distal receptors had equal absorption coefficients (kD=0.0067 μm–1), we found that self-screening within the scallop eye caused the proximal and distal receptors in P. magellanicus to have peak absorption at 490 and 520 nm, respectively, and the corresponding receptors in A. irradians to have peak absorption at 504 and 549 nm. We conclude that environment may influence the λmax of scallop visual pigments: P. magellanicus, generally found in blue oceanic water, has visual pigments that are maximally sensitive to shorter wavelengths than those found in A. irradians, which lives in greener inshore water. Scallop distal retinas may be sensitive to longer wavelengths of light than scallop proximal retinas to correct for either self-screening by the retinas or longitudinal chromatic aberration of the lens.
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Affiliation(s)
| | - Ellis R. Loew
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Sönke Johnsen
- Biology Department, Duke University, Durham, NC 27708, USA
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Talbot CM, Marshall J. Polarization sensitivity and retinal topography of the striped pyjama squid (Sepioloidea lineolata - Quoy/Gaimard 1832). ACTA ACUST UNITED AC 2010; 213:3371-7. [PMID: 20833931 DOI: 10.1242/jeb.048165] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Coleoid cephalopods (octopus, cuttlefish and squid) potentially possess polarization sensitivity (PS) based on photoreceptor structure, but this idea has rarely been tested behaviourally. Here, we use a polarized, striped optokinetic stimulus to demonstrate PS in the striped pyjama squid, Sepioloidea lineolata. This species displayed strong, consistent optokinetic nystagmic eye movements in response to a drum with stripes producing e-vectors set to 0 deg, 45 deg, 90 deg and 135 deg that would only be visible to an animal with PS. This is the first behavioural demonstration of a polarized optokinetic response in any species of cephalopod. This species, which typically sits beneath the substrate surface looking upwards for potential predators and prey, possesses a dorsally shifted horizontal pupil slit. Accordingly, it was found to possess a horizontal strip of high-density photoreceptors shifted ventrally in the retina, suggesting modifications such as a change in sensitivity or resolution to the dorsal visual field.
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Affiliation(s)
- Christopher M Talbot
- The Sensory Neurobiology Group, Queensland Brain Institute, and the School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
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Wagner HJ, Douglas RH, Frank TM, Roberts NW, Partridge JC. A Novel Vertebrate Eye Using Both Refractive and Reflective Optics. Curr Biol 2009; 19:108-14. [DOI: 10.1016/j.cub.2008.11.061] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 11/17/2008] [Accepted: 11/17/2008] [Indexed: 11/25/2022]
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Abstract
The deep sea is the largest habitat on earth. Its three great faunal environments--the twilight mesopelagic zone, the dark bathypelagic zone and the vast flat expanses of the benthic habitat--are home to a rich fauna of vertebrates and invertebrates. In the mesopelagic zone (150-1000 m), the down-welling daylight creates an extended scene that becomes increasingly dimmer and bluer with depth. The available daylight also originates increasingly from vertically above, and bioluminescent point-source flashes, well contrasted against the dim background daylight, become increasingly visible. In the bathypelagic zone below 1000 m no daylight remains, and the scene becomes entirely dominated by point-like bioluminescence. This changing nature of visual scenes with depth--from extended source to point source--has had a profound effect on the designs of deep-sea eyes, both optically and neurally, a fact that until recently was not fully appreciated. Recent measurements of the sensitivity and spatial resolution of deep-sea eyes--particularly from the camera eyes of fishes and cephalopods and the compound eyes of crustaceans--reveal that ocular designs are well matched to the nature of the visual scene at any given depth. This match between eye design and visual scene is the subject of this review. The greatest variation in eye design is found in the mesopelagic zone, where dim down-welling daylight and bio-luminescent point sources may be visible simultaneously. Some mesopelagic eyes rely on spatial and temporal summation to increase sensitivity to a dim extended scene, while others sacrifice this sensitivity to localise pinpoints of bright bioluminescence. Yet other eyes have retinal regions separately specialised for each type of light. In the bathypelagic zone, eyes generally get smaller and therefore less sensitive to point sources with increasing depth. In fishes, this insensitivity, combined with surprisingly high spatial resolution, is very well adapted to the detection and localisation of point-source bioluminescence at ecologically meaningful distances. At all depths, the eyes of animals active on and over the nutrient-rich sea floor are generally larger than the eyes of pelagic species. In fishes, the retinal ganglion cells are also frequently arranged in a horizontal visual streak, an adaptation for viewing the wide flat horizon of the sea floor, and all animals living there. These and many other aspects of light and vision in the deep sea are reviewed in support of the following conclusion: it is not only the intensity of light at different depths, but also its distribution in space, which has been a major force in the evolution of deep-sea vision.
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Affiliation(s)
- Eric J Warrant
- Department of Cell & Organism Biology, University of Lund, Helgonavägen 3, S-22362 Lund, Sweden.
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Warrant E. Vision in the dimmest habitats on earth. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2004; 190:765-89. [PMID: 15375626 DOI: 10.1007/s00359-004-0546-z] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Revised: 06/24/2004] [Accepted: 06/27/2004] [Indexed: 11/29/2022]
Abstract
A very large proportion of the world's animal species are active in dim light, either under the cover of night or in the depths of the sea. The worlds they see can be dim and extended, with light reaching the eyes from all directions at once, or they can be composed of bright point sources, like the multitudes of stars seen in a clear night sky or the rare sparks of bioluminescence that are visible in the deep sea. The eye designs of nocturnal and deep-sea animals have evolved in response to these two very different types of habitats, being optimised for maximum sensitivity to extended scenes, or to point sources, or to both. After describing the many visual adaptations that have evolved across the animal kingdom for maximising sensitivity to extended and point-source scenes, I then use case studies from the recent literature to show how these adaptations have endowed nocturnal animals with excellent vision. Nocturnal animals can see colour and negotiate dimly illuminated obstacles during flight. They can also navigate using learned terrestrial landmarks, the constellations of stars or the dim pattern of polarised light formed around the moon. The conclusion from these studies is clear: nocturnal habitats are just as rich in visual details as diurnal habitats are, and nocturnal animals have evolved visual systems capable of exploiting them. The same is certainly true of deep-sea animals, as future research will no doubt reveal.
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Affiliation(s)
- Eric Warrant
- Vision Group, Department of Cell and Organism Biology, University of Lund, Helgonavägen 3, 22362 Lund, Sweden.
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Johnsen S, Widder EA, Mobley CD. Propagation and perception of bioluminescence: factors affecting counterillumination as a cryptic strategy. THE BIOLOGICAL BULLETIN 2004; 207:1-16. [PMID: 15315939 DOI: 10.2307/1543624] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Many deep-sea species, particularly crustaceans, cephalopods, and fish, use photophores to illuminate their ventral surfaces and thus disguise their silhouettes from predators viewing them from below. This strategy has several potential limitations, two of which are examined here. First, a predator with acute vision may be able to detect the individual photophores on the ventral surface. Second, a predator may be able to detect any mismatch between the spectrum of the bioluminescence and that of the background light. The first limitation was examined by modeling the perceived images of the counterillumination of the squid Abralia veranyi and the myctophid fish Ceratoscopelus maderensis as a function of the distance and visual acuity of the viewer. The second limitation was addressed by measuring downwelling irradiance under moonlight and starlight and then modeling underwater spectra. Four water types were examined: coastal water at a depth of 5 m and oceanic water at 5, 210, and 800 m. The appearance of the counterillumination was more affected by the visual acuity of the viewer than by the clarity of the water, even at relatively large distances. Species with high visual acuity (0.11 degrees resolution) were able to distinguish the individual photophores of some counterilluminating signals at distances of several meters, thus breaking the camouflage. Depth and the presence or absence of moonlight strongly affected the spectrum of the background light, particularly near the surface. The increased variability near the surface was partially offset by the higher contrast attenuation at shallow depths, which reduced the sighting distance of mismatches. This research has implications for the study of spatial resolution, contrast sensitivity, and color discrimination in deep-sea visual systems.
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Affiliation(s)
- Sönke Johnsen
- Biology Department, Duke University, Durham, North Carolina 27708, USA.
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Röll B. Retina of Bouton's skink (Reptilia, Scincidae): visual cells, fovea, and ecological constraints. J Comp Neurol 2001; 436:487-96. [PMID: 11447591 DOI: 10.1002/cne.1082] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bouton's skink, Cryptoblepharus boutonii africanus, is a small, diurnal lizard living on outcrops along the coast of East Africa under high ambient light intensities. It is characterized by relatively large eyes (maximal diameter about 2 mm), with immovable eyelids forming a transparent spectacle and with a virtually constant pupil diameter. The single fovea in the central retina is well developed, with a clearly defined pit, which is relatively deep but not funnel-shaped. The foveal pit is not devoid of the outer nuclear and outer plexiform layers; only the main part of the inner nuclear layer is displaced laterally, resulting in a pit with gradual sloping towards its edges. Thus, the fovea appears to be concaviclivate, as in the eyes of lacertids, varanids, and gekkonids. The central position of the foveae in these laterally placed scincid eyes corresponds with monocular fixation, e.g., of detected prey. C. boutonii has a pure-cone retina containing single and double visual cells. The latter consist of two cells of unequal sizes. Yellowish oil droplets are present in single cones and the minor members of the double cones in all retinal regions. The visual cells of the different retinal regions do not differ in the ultrastructure of their components but differ considerably in size. The outer segments of the foveal cones are twice as long as those of the peripheral cones. Except for the pedicles, the diameters of the components of the visual cells decrease towards the fovea, resulting in an increase in visual acuity.
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Affiliation(s)
- B Röll
- Lehrstuhl für Tierphysiologie, Fakultät für Biologie, Ruhr-Universität Bochum, D-44780 Bochum, Germany.
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Abstract
Midwater predators often have double eyes consisting of a large upward-pointing part with a narrow field of view and high resolution, and a small downward-pointing part with a wide field of view and low resolution. In crustaceans with compound eyes the different eye parts are of basically similar construction, but in fishes the downward-pointing regions may employ unusual optical systems with unknown image-forming capabilities. It has been suggested that the upward-directed parts are used to detect silhouettes of animals against the residual daylight, whereas the lower parts look out for luminescent organisms. Here I calculate the sizes that apposition compound eyes would need to attain in order to fulfil these tasks, and the way that size should vary with depth. It is concluded that silhouette detection is much the more demanding task, and becomes increasingly difficult as light levels decrease. For this reason the upward-pointing parts must increase rapidly with depth. This is not the case with luminescence detectors, where the task is most difficult near the surface because of upwelling background light, and becomes easier with depth. On the whole these predictions fit well with the sizes and shapes of real midwater eyes, especially in the case of the hyperiid amphipods.
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Affiliation(s)
- M F Land
- School of Biological Sciences, University of Sussex, Brighton, UK
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Wagner HJ, Fröhlich E, Negishi K, Collin SP. The eyes of deep-sea fish. II. Functional morphology of the retina. Prog Retin Eye Res 1998; 17:637-85. [PMID: 9777652 DOI: 10.1016/s1350-9462(98)00003-2] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Three different aspects of the morphological organisation of deep-sea fish retinae are reviewed: First, questions of general cell biological relevance are addressed with respect to the development and proliferation patterns of photoreceptors, and problems associated with the growth of multibank retinae, and with outer segment renewal are discussed in situations where there is no direct contact between the retinal pigment epithelium and the tips of rod outer segments. The second part deals with the neural portion of the deep-sea fish retina. Cell densities are greatly reduced, yet neurohistochemistry demonstrates that all major neurotransmitters and neuropeptides found in other vertebrate retinae are also present in deep-sea fish. Quantitatively, convergence rates in unspecialised parts of the retina are similar to those in nocturnal mammals. The differentiation of horizontal cells makes it unlikely that species with more than a single visual pigment are capable of colour vision. In the third part, the diversity of deep-sea fish retinae is highlighted. Based on the topography of ganglion cells, species are identified with areae or foveae located in various parts of the retina, giving them a greatly improved spatial resolving power in specific parts of their visual fields. The highest degree of specialisation is found in tubular eyes. This is demonstrated in a case study of the scopelarchid retina, where as many as seven regions with different degrees of differentiation can be distinguished, ranging from an area giganto cellularis, regions with grouped rods to retinal diverticulum.
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Affiliation(s)
- H J Wagner
- Anatomisches Institut, Eberhard-Karls-Universität Tübingen, Germany
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