1
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Lau IH, Vasconcelos RO. Noise-induced damage in the zebrafish inner ear endorgans: evidence for higher acoustic sensitivity of saccular and lagenar hair cells. J Exp Biol 2023; 226:jeb245992. [PMID: 37767687 DOI: 10.1242/jeb.245992] [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: 04/24/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023]
Abstract
The three otolithic endorgans of the inner ear are known to be involved in sound detection in different teleost fishes, yet their relative roles for auditory-vestibular functions within the same species remain uncertain. In zebrafish (Danio rerio), the saccule and utricle are thought to play key functions in encoding auditory and vestibular information, respectively, but the biological function of the lagena is not clear. We hypothesized that the zebrafish saccule serves as a primary auditory endorgan, making it more vulnerable to noise exposure, and that the lagena might have an auditory function given its connectivity to the saccule and the dominant vestibular function of the utricle. We compared the impact of acoustic trauma (continuous white noise at 168 dB for 24 h) between the sensory epithelia of the three otolithic endorgans. Noise treatment caused hair cell loss in both the saccule and lagena but not in the utricle. This effect was identified immediately after acoustic treatment and did not increase 24 h post-trauma. Furthermore, hair cell loss was accompanied by a reduction in presynaptic activity measured based on ribeye b presence, but mainly in the saccule, supporting its main contribution for noise-induced hearing loss. Our findings support the hypothesis that the saccule plays a major role in sound detection and that the lagena is also acoustically affected, extending the species hearing dynamic range.
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Affiliation(s)
- Ieng Hou Lau
- Institute of Science and Environment, University of Saint Joseph, Macao, S.A.R., China
| | - Raquel O Vasconcelos
- Institute of Science and Environment, University of Saint Joseph, Macao, S.A.R., China
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal
- EPCV-Department of Life Sciences, Lusófona University, 1749-024 Lisbon, Portugal
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2
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Bendig TA, Dycha GM, Bull EM, Ayala-Osorio R, Higgs DM. A comparative analysis of form and function in Centrarchidae hearing ability: Does otolith variation affect auditory responsiveness? THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:772-780. [PMID: 37563826 DOI: 10.1121/10.0020587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023]
Abstract
There exists a wealth of knowledge on hearing ability in individual fish species, but the role of interspecific variation, and drivers behind it, remains understudied, making it difficult to understand evolutionary drivers. The current study quantified hearing thresholds for three species of sunfish in the family Centrarchidae [bluegill sunfish (Lepomis macrochirus), pumpkinseed sunfish (Lepomis gibbosus), and rock bass (Ambloplites rupestris)] using auditory evoked potentials and behavioral trials and saccular otolith size and hair cell density. In auditory physiological experiments, 10-ms tone bursts were played and responses monitored to measure hearing. In behavioral experiments, fish were exposed to the same tone bursts for 1 s, and changes in fish behaviors were monitored. Saccular otolith morphology and hair cell densities were also quantified. Physiological thresholds varied between species, but behavioral thresholds did not. Rock bass had larger S:O ratio (percentage of the saccular otolith surface occupied by the sulcus), but no differences in hair cell densities were found. Our study allows for a direct comparison between confamilial species, allowing a deeper understanding of sound detection abilities and possible mechanisms driving differential hearing. Using both approaches also allows future research into how these species may be impacted by increasing levels of anthropogenic noise.
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Affiliation(s)
- Taylor A Bendig
- Integrative Biology, Faculty of Science, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Grace M Dycha
- Integrative Biology, Faculty of Science, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Elise M Bull
- Integrative Biology, Faculty of Science, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Roselia Ayala-Osorio
- Integrative Biology, Faculty of Science, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Dennis M Higgs
- Integrative Biology, Faculty of Science, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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3
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Sauer DJ, Radford CA, Mull CG, Yopak KE. Quantitative assessment of inner ear variation in elasmobranchs. Sci Rep 2023; 13:11939. [PMID: 37488259 PMCID: PMC10366120 DOI: 10.1038/s41598-023-39151-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/20/2023] [Indexed: 07/26/2023] Open
Abstract
Considerable diversity has been documented in most sensory systems of elasmobranchs (sharks, rays, and skates); however, relatively little is known about morphological variation in the auditory system of these fishes. Using magnetic resonance imaging (MRI), the inner ear structures of 26 elasmobranchs were assessed in situ. The inner ear end organs (saccule, lagena, utricle, and macula neglecta), semi-circular canals (horizontal, anterior, and posterior), and endolymphatic duct were compared using phylogenetically-informed, multivariate analyses. Inner ear variation can be characterised by three primary axes that are influenced by diet and habitat, where piscivorous elasmobranchs have larger inner ears compared to non-piscivorous species, and reef-associated species have larger inner ears than oceanic species. Importantly, this variation may reflect differences in auditory specialisation that could be tied to the functional requirements and environmental soundscapes of different species.
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Affiliation(s)
- Derek J Sauer
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Leigh, New Zealand.
| | - Craig A Radford
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Leigh, New Zealand
| | - Christopher G Mull
- Integrated Fisheries Laboratory, Department of Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Kara E Yopak
- Department of Biology and Marine Biology and the Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC, USA
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4
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Baeza-Loya S, Raible DW. Vestibular physiology and function in zebrafish. Front Cell Dev Biol 2023; 11:1172933. [PMID: 37143895 PMCID: PMC10151581 DOI: 10.3389/fcell.2023.1172933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/06/2023] [Indexed: 05/06/2023] Open
Abstract
The vestibular system of the inner ear provides information about head motion and spatial orientation relative to gravity to ensure gaze stability, balance, and postural control. Zebrafish, like humans, have five sensory patches per ear that serve as peripheral vestibular organs, with the addition of the lagena and macula neglecta. The zebrafish inner ear can be easily studied due to its accessible location, the transparent tissue of larval fish, and the early development of vestibular behaviors. Thus, zebrafish are an excellent model for studying the development, physiology, and function of the vestibular system. Recent work has made great strides to elucidate vestibular neural circuitry in fish, tracing sensory transmission from receptors in the periphery to central computational circuits driving vestibular reflexes. Here we highlight recent work that illuminates the functional organization of vestibular sensory epithelia, innervating first-order afferent neurons, and second-order neuronal targets in the hindbrain. Using a combination of genetic, anatomical, electrophysiological, and optical techniques, these studies have probed the roles of vestibular sensory signals in fish gaze, postural, and swimming behaviors. We discuss remaining questions in vestibular development and organization that are tractable in the zebrafish model.
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Affiliation(s)
| | - David W. Raible
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-HNS and Biological Structure, University of Washington, Seattle, WA, United States
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5
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Sauer DJ, Yopak KE, Radford CA. Ontogenetic development of inner ear hair cell organization in the New Zealand carpet shark Cephaloscyllium isabellum. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1034891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
IntroductionThe inner ear hair cells of fishes can provide insight into the early evolution of vertebrate inner ear structure. Fishes represent some of the first vertebrates to evolve auditory capacity, and the same basic structure, the sensory hair cell, provides the fundament for auditory and vestibular function in jawed vertebrates. Despite holding critical basal position in the evolutionary tree of gnathostomes, relatively little is known about inner ear hair cells in elasmobranchs. Specifically, the extent of plasticity in hair cell organization throughout ontogeny among different sensory epithelia and the degree of variation between species is unknown.MethodsIn this study, we characterized the inner ear hair cells of the New Zealand carpet shark Cephaloscyllium isabellum throughout ontogeny by quantifying macular area, number of hair cells, hair cell density, and hair cell orientations in the inner ear maculae from a range of body sizes.ResultsSimilar to other elasmobranchs and bony fishes, macular area and the number of hair cells increased throughout ontogeny in the otolith organs. The orientations of hair cells within each maculae also was consistent with the limited data on other elasmobranchs. However, contrary to expectation, the macula neglecta did not increase in area or hair cell number throughout ontogeny, and hair cell density did not change with body size in any maculae.DiscussionThese findings suggest there may be variation between elasmobranch species in ontogenetic development of hair cell organization that may be related to hearing capabilities throughout life.
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6
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Rogers LS, Van Wert JC, Mensinger AF. Response of toadfish ( Opsanus tau) utricular afferents to multimodal inputs. J Neurophysiol 2022; 128:364-377. [PMID: 35830608 DOI: 10.1152/jn.00483.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The inner ear of teleost fishes is composed of three paired multimodal otolithic end organs (saccule, utricle, and lagena), which encode auditory and vestibular inputs via the deflection of hair cells contained within the sensory epithelia of each organ. However, it remains unclear how the multimodal otolithic end organs of the teleost inner ear simultaneously integrate vestibular and auditory inputs. Therefore, microwire electrodes were chronically implanted using a 3D printed micromanipulator into the utricular nerve of oyster toadfish (Opsanus tau) to determine how utricular afferents respond to conspecific mate vocalizations termed boatwhistles (180 Hz fundamental frequency) during movement. Utricular afferents were recorded while fish were passively moved using a sled system along an underwater track at variable speeds (velocity: 4.0 - 12.5 cm/s; acceleration: 0.2 - 2.6 cm/s2) and while fish freely swam (velocity: 3.5 - 18.6 cm/s; acceleration: 0.8 - 29.8 cm/s2). Afferent fiber activities (spikes/s) increased in response to the onset of passive and active movements; however, afferent fibers differentially adapted to sustained movements. Additionally, utricular afferent fibers remained sensitive to playbacks of conspecific male boatwhistle vocalizations during both passive and active movements. Here, we demonstrate in alert toadfish that utricular afferents exhibit enhanced activity levels (spikes/s) in response to behaviorally-relevant acoustic stimuli during swimming.
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Affiliation(s)
- Loranzie S Rogers
- Biology Department, University of Minnesota Duluth, Duluth, MN, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | | | - Allen F Mensinger
- Biology Department, University of Minnesota Duluth, Duluth, MN, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
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7
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Maiditsch IP, Ladich F, Heß M, Schlepütz CM, Schulz-Mirbach T. Revealing sound-induced motion patterns in fish hearing structures in 4D: a standing wave tube-like setup designed for high-resolution time-resolved tomography. J Exp Biol 2022; 225:273722. [PMID: 34904652 PMCID: PMC8778803 DOI: 10.1242/jeb.243614] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/08/2021] [Indexed: 02/02/2023]
Abstract
Modern bony fishes possess a high morphological diversity in their auditory structures and auditory capabilities. Yet, how auditory structures such as the otoliths in the inner ears and the swim bladder work together remains elusive. Gathering experimental evidence on the in situ motion of fish auditory structures while avoiding artifacts caused by surgical exposure of the structures has been challenging for decades. Synchrotron radiation-based tomography with high spatio-temporal resolution allows the study of morphofunctional issues non-invasively in an unprecedented way. We therefore aimed to develop an approach that characterizes the moving structures in 4D (=three spatial dimensions+time). We designed a miniature standing wave tube-like setup to meet both the requirements of tomography and those of tank acoustics. With this new setup, we successfully visualized the motion of isolated otoliths and the auditory structures in zebrafish (Danio rerio) and glass catfish (Kryptopterus vitreolus). Summary: To characterize the sound-induced motion of fish auditory structures in 4D, we developed a tomography-compatible standing wave tube-like setup and thereby demonstrated the previously hypothesized rotational motion of otophysan sagittae.
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Affiliation(s)
- Isabelle P Maiditsch
- University of Vienna, Department of Behavioral and Cognitive Biology, 1030 Vienna, Austria
| | - Friedrich Ladich
- University of Vienna, Department of Behavioral and Cognitive Biology, 1030 Vienna, Austria
| | - Martin Heß
- Ludwig-Maximilians-University Munich (LMU), Department Biology II, Planegg-Martinsried, 82152Germany
| | | | - Tanja Schulz-Mirbach
- Ludwig-Maximilians-University Munich (LMU), Department Biology II, Planegg-Martinsried, 82152Germany
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8
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Rogers LS, Sisneros JA. Auditory evoked potentials of utricular hair cells in the plainfin midshipman, Porichthys notatus. J Exp Biol 2020; 223:jeb226464. [PMID: 32680899 DOI: 10.1242/jeb.226464] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/10/2020] [Indexed: 11/20/2022]
Abstract
The plainfin midshipman, Porichthys notatus, is a soniferous marine teleost fish that generates acoustic signals for intraspecific social communication. Nocturnally active males and females rely on their auditory sense to detect and locate vocally active conspecifics during social behaviors. Previous work showed that the midshipman inner ear saccule and lagena are highly adapted to detect and encode socially relevant acoustic stimuli, but the auditory sensitivity and function of the midshipman utricle remain largely unknown. Here, we characterized the auditory evoked potentials from hair cells in the utricle of non-reproductive type I males and tested the hypothesis that the midshipman utricle is sensitive to behaviorally relevant acoustic stimuli. Hair cell potentials were recorded from the rostral, medial and caudal regions of the utricle in response to pure tone stimuli presented by an underwater speaker. We show that the utricle is highly sensitive to particle motion stimuli produced by an underwater speaker positioned in the horizontal plane. Utricular potentials were recorded across a broad range of frequencies with lowest particle acceleration (dB re. 1 m s-2) thresholds occurring at 105 Hz (lowest frequency tested; mean threshold -32 dB re. 1 m s-2) and highest thresholds at 605-1005 Hz (mean threshold range -5 to -4 dB re. 1 m s-2). The high gain and broadband frequency sensitivity of the utricle suggest that it likely serves a primary auditory function and is well suited to detect conspecific vocalizations including broadband agonistic signals and the multiharmonic advertisement calls produced by reproductive type I males.
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Affiliation(s)
- Loranzie S Rogers
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
| | - Joseph A Sisneros
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA 98195, USA
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9
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A geometric morphometric approach for disparity of the sulcus acusticus of sagitta in species of Gerreidae (Teleostei: Perciformes). ORG DIVERS EVOL 2020. [DOI: 10.1007/s13127-019-00429-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Teimori A, Motamedi M, Zeinali F. Intrapopulation variation of otolith associated with ontogeny and morphological dimorphism in Hormuz tooth‐carp
Aphanius hormuzensis
(Teleostei: Aphaniidae). ACTA ZOOL-STOCKHOLM 2020. [DOI: 10.1111/azo.12332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Azad Teimori
- Department of Biology Faculty of Sciences Shahid Bahonar University of Kerman Kerman Iran
| | - Mina Motamedi
- Department of Biology Faculty of Sciences Shahid Bahonar University of Kerman Kerman Iran
| | - Faezeh Zeinali
- Department of Biology Faculty of Sciences Shahid Bahonar University of Kerman Kerman Iran
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11
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Bird NC, Richardson SS, Abels JR. Histological development and integration of the Zebrafish Weberian apparatus. Dev Dyn 2020; 249:998-1017. [DOI: 10.1002/dvdy.172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 03/18/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Nathan C. Bird
- Department of Biology, McCollum Science Hall 107; University of Northern Iowa; Cedar Falls Iowa
| | - Selena S. Richardson
- Department of Biology, McCollum Science Hall 107; University of Northern Iowa; Cedar Falls Iowa
| | - Jeremy R. Abels
- Department of Biology, McCollum Science Hall 107; University of Northern Iowa; Cedar Falls Iowa
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12
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Byrd BL, Hohn AA, Krause JR. Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator. Ecol Evol 2020; 10:3584-3604. [PMID: 32313620 PMCID: PMC7160159 DOI: 10.1002/ece3.6085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 12/20/2019] [Accepted: 12/30/2019] [Indexed: 11/17/2022] Open
Abstract
Diet studies are fundamental for understanding trophic connections in marine ecosystems. In the southeastern US, the common bottlenose dolphin Tursiops truncatus is the predominant marine mammal in coastal waters, but its role as a top predator has received little attention. Diet studies of piscivorous predators, like bottlenose dolphins, start with assessing prey otoliths recovered from stomachs or feces, but digestive erosion hampers species identification and underestimates fish weight (FW). To compensate, FW is often estimated from the least affected otoliths and scaled to other otoliths, which also introduces bias. The sulcus, an otolith surface feature, has a species-specific shape of its ostium and caudal extents, which is within the otolith edge for some species. We explored whether the sulcus could improve species identification and estimation of prey size using a case study of four sciaenid species targeted by fisheries and bottlenose dolphins in North Carolina. Methods were assessed first on otoliths from a reference collection (n = 421) and applied to prey otoliths (n = 5,308) recovered from 120 stomachs of dead stranded dolphins. We demonstrated in reference-collection otoliths that cauda to sulcus length (CL:SL) could discriminate between spotted seatrout (Cynoscion nebulosus) and weakfish (Cynoscion regalis) (classification accuracy = 0.98). This method confirmed for the first time predation of spotted seatrout by bottlenose dolphins in North Carolina. Using predictive models developed from reference-collection otoliths, we provided evidence that digestion affects otolith length more than sulcus or cauda length, making the latter better predictors. Lastly, we explored scenarios of calculating total consumed biomass across degrees of digestion. A suggested approach was for the least digested otoliths to be scaled to other otoliths iteratively from within the same stomach, month, or season as samples allow. Using the otolith sulcus helped overcome challenges of species identification and fish size estimation, indicating their potential use in other diet studies.
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Affiliation(s)
- Barbie L. Byrd
- National Oceanic and Atmospheric Administration (NOAA)National Marine Fisheries Service (NMFS)Southeast Fisheries Science CenterRiverside Technology ContractorBeaufortNCUSA
| | - Aleta A. Hohn
- NOAANMFSSoutheast Fisheries Science CenterBeaufortNCUSA
| | - Jacob R. Krause
- Department of Applied EcologyCenter for Marine Sciences and TechnologyNorth Carolina State UniversityMorehead CityNCUSA
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13
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Schnetz L, Pfaff C, Libowitzky E, Johanson Z, Stepanek R, Kriwet J. Morphology and evolutionary significance of phosphatic otoliths within the inner ears of cartilaginous fishes (Chondrichthyes). BMC Evol Biol 2019; 19:238. [PMID: 31888446 PMCID: PMC6937729 DOI: 10.1186/s12862-019-1568-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 12/17/2019] [Indexed: 12/02/2022] Open
Abstract
Background Chondrichthyans represent a monophyletic group of crown group gnathostomes and are central to our understanding of vertebrate evolution. Like all vertebrates, cartilaginous fishes evolved concretions of material within their inner ears to aid with equilibrium and balance detection. Up to now, these materials have been identified as calcium carbonate-bearing otoconia, which are small bio-crystals consisting of an inorganic mineral and a protein, or otoconial masses (aggregations of otoconia bound by an organic matrix), being significantly different in morphology compared to the singular, polycrystalline otolith structures of bony fishes, which are solidified bio-crystals forming stony masses. Reinvestigation of the morphological and chemical properties of these chondrichthyan otoconia revises our understanding of otolith composition and has implications on the evolution of these characters in both the gnathostome crown group, and cartilaginous fishes in particular. Results Dissections of Amblyraja radiata, Potamotrygon leopoldi, and Scyliorhinus canicula revealed three pairs of singular polycrystalline otolith structures with a well-defined morphology within their inner ears, as observed in bony fishes. IR spectroscopy identified the material to be composed of carbonate/collagen-bearing apatite in all taxa. These findings contradict previous hypotheses suggesting these otoconial structures were composed of calcium carbonate in chondrichthyans. A phylogenetic mapping using 37 chondrichthyan taxa further showed that the acquisition of phosphatic otolith structures might be widespread within cartilaginous fishes. Conclusions Differences in the size and shape of otoliths between taxa indicate a taxonomic signal within elasmobranchs. Otoliths made of carbonate/collagen-bearing apatite are reported for the first time in chondrichthyans. The intrinsic pathways to form singular, polycrystalline otoliths may represent the plesiomorphic condition for vertebrates but needs further testing. Likewise, the phosphatic composition of otoliths in early vertebrates such as cyclostomes and elasmobranchs is probably closely related to the lack of bony tissue in these groups, supporting a close relationship between skeletal tissue mineralization patterns and chemical otolith composition, underlined by physiological constraints.
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Affiliation(s)
- Lisa Schnetz
- University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15 2TT, UK.
| | - Cathrin Pfaff
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Institute of Palaeontology, Geozentrum, Althanstraße 14, 1090, Vienna, Austria
| | - Eugen Libowitzky
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Institute of Mineralogy and Crystallography, Geozentrum, Althanstraße 14, 1090, Vienna, Austria
| | - Zerina Johanson
- Department of Earth Sciences, Natural History Museum, London, SW7 5BD, UK
| | - Rica Stepanek
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Institute of Palaeontology, Geozentrum, Althanstraße 14, 1090, Vienna, Austria
| | - Jürgen Kriwet
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Institute of Palaeontology, Geozentrum, Althanstraße 14, 1090, Vienna, Austria.
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14
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Pfaff C, Schultz JA, Schellhorn R. The vertebrate middle and inner ear: A short overview. J Morphol 2019; 280:1098-1105. [PMID: 30117612 PMCID: PMC6766920 DOI: 10.1002/jmor.20880] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 06/30/2018] [Accepted: 07/05/2018] [Indexed: 01/11/2023]
Abstract
The evolution of the various hearing adaptations is connected to major structural changes in nearly all groups of vertebrates. Besides hearing, the detection of acceleration and orientation in space are key functions of this mechanosensory system. The symposium "show me your ear - the inner and middle ear in vertebrates" held at the 11th International Congress of Vertebrate Morphology (ICVM) 2016 in Washington, DC (USA) intended to present current research addressing adaptation and evolution of the vertebrate otic region, auditory ossicles, vestibular system, and hearing physiology. The symposium aimed at an audience with interest in hearing research focusing on morphological, functional, and comparative studies. The presented talks and posters lead to the contributions of this virtual issue highlighting recent advances in the vertebrate balance and hearing system. This article serves as an introduction to the virtual issue contributions and intends to give a short overview of research papers focusing on vertebrate labyrinth and middle ear related structures in past and recent years.
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Affiliation(s)
- Cathrin Pfaff
- University of Vienna, Department of PalaeontologyViennaAustria
| | - Julia A. Schultz
- University of Chicago, Department of Organismal Biology and AnatomyChicagoIllinoisUSA
- Rheinische Friedrich‐Wilhelms‐Universität Bonn, Steinmann Institut für Geologie, Mineralogie und PaläontologieBonnGermany
| | - Rico Schellhorn
- Rheinische Friedrich‐Wilhelms‐Universität Bonn, Steinmann Institut für Geologie, Mineralogie und PaläontologieBonnGermany
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15
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Vetter BJ, Seeley LH, Sisneros JA. Lagenar potentials of the vocal plainfin midshipman fish, Porichthys notatus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:163-175. [PMID: 30635725 DOI: 10.1007/s00359-018-01314-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/19/2018] [Accepted: 12/26/2018] [Indexed: 11/29/2022]
Abstract
The plainfin midshipman fish (Porichthys notatus) is a species of marine teleost that produces acoustic signals that are important for mediating social behavior. The auditory sensitivity of the saccule is well established in this species, but the sensitivity and function of the midshipman's putative auditory lagena are unknown. Here, we characterize the auditory-evoked potentials from hair cells in the lagena of reproductive type I males to determine the frequency response and auditory sensitivity of the lagena to behaviorally relevant acoustic stimuli. Lagenar potentials were recorded from the caudal and medial region of the lagena, while acoustic stimuli were presented by an underwater speaker. Our results indicate that the midshipman lagena has a similar low-frequency sensitivity to that of the midshipman saccule based on sound pressure and acceleration (re: 1 µPa and 1 ms-2, respectively), but the thresholds of the lagena were higher across all frequencies tested. The relatively high auditory thresholds of the lagena may be important for encoding high levels of behaviorally relevant acoustic stimuli when close to a sound source.
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Affiliation(s)
- Brooke J Vetter
- Department of Psychology, University of Washington, Seattle, WA, 98195-1525, USA.
| | - Lane H Seeley
- Department of Physics, Seattle Pacific University, Seattle, WA, 98199-1997, USA
| | - Joseph A Sisneros
- Department of Psychology, University of Washington, Seattle, WA, 98195-1525, USA.,Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, 98195-7923, USA
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Hawkins AD, Popper AN. Directional hearing and sound source localization by fishes. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 144:3329. [PMID: 30599653 DOI: 10.1121/1.5082306] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
Directional hearing may enable fishes to seek out prey, avoid predators, find mates, and detect important spatial cues. Early sound localization experiments gave negative results, and it was thought unlikely that fishes utilized the same direction-finding mechanisms as terrestrial vertebrates. However, fishes swim towards underwater sound sources, and some can discriminate between sounds from different directions and distances. The otolith organs of the inner ear detect the particle motion components of sound, acting as vector detectors through the presence of sensory hair cells with differing orientation. However, many questions remain on inner ear functioning. There are problems in understanding the actual mechanisms involved in determining sound direction and distance. Moreover, very little is still known about the ability of fishes to locate sound sources in three-dimensional space. Do fishes swim directly towards a source, or instead "sample" sound levels while moving towards the source? To what extent do fishes utilize other senses and especially vision in locating the source? Further behavioral studies of free-swimming fishes are required to provide better understanding of how fishes might actually locate sound sources. In addition, more experiments are required on the auditory mechanism that fishes may utilize.
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Affiliation(s)
| | - Arthur N Popper
- Department of Biology, University of Maryland, College Park, Maryland 20742, USA
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17
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Jawad LA. A comparative morphological investigation of otoliths of six parrotfish species (Scaridae) from the Solomon Islands. JOURNAL OF FISH BIOLOGY 2018; 93:1046-1058. [PMID: 30144076 DOI: 10.1111/jfb.13787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/22/2018] [Indexed: 06/08/2023]
Abstract
A comparative morphological investigation of otoliths from six parrotfish species and two genera, Scarus and Hipposcarus, was conducted to identify taxonomically diagnostic species-specific characters. Ontogenetic trends in otolith morphology were evident: Otoliths of small-sized specimens were most like those of large-sized Scarus oviceps and were least similar to large-sized Hipposcarus longiceps.
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Affiliation(s)
- Laith A Jawad
- 4 Tinturn Place, Flat Bush, Manukau, Auckland 2016, New Zealand
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Schulz-Mirbach T, Ladich F, Plath M, Heß M. Enigmatic ear stones: what we know about the functional role and evolution of fish otoliths. Biol Rev Camb Philos Soc 2018; 94:457-482. [DOI: 10.1111/brv.12463] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 08/16/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Tanja Schulz-Mirbach
- Department Biology II, Zoology; Ludwig-Maximilians-University; Großhaderner Strasse 2, 82152 Planegg-Martinsried Germany
| | - Friedrich Ladich
- Department of Behavioural Biology; University of Vienna; Althanstrasse 14, 1090 Vienna Austria
| | - Martin Plath
- College of Animal Science & Technology; Northwest A&F University; 22 Xinong Road, Yangling Shaanxi China
| | - Martin Heß
- Department Biology II, Zoology; Ludwig-Maximilians-University; Großhaderner Strasse 2, 82152 Planegg-Martinsried Germany
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Lombarte A, Miletić M, Kovačić M, Otero-Ferrer JL, Tuset VM. Identifying sagittal otoliths of Mediterranean Sea gobies: variability among phylogenetic lineages. JOURNAL OF FISH BIOLOGY 2018; 92:1768-1787. [PMID: 29756341 DOI: 10.1111/jfb.13615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/03/2018] [Indexed: 06/08/2023]
Abstract
In this study, we describe and analyse the morphology of the sagitta, the largest otolith, of 25 species of Gobiidae inhabiting the Adriatic and north-western Mediterranean seas. Our goal was to test the usefulness and efficiency of sagittal otoliths for species identification. Our analysis of otolith contours was based on mathematical descriptors called wavelets, which are related to multi-scale decompositions of contours. Two methods of classification were used: an iterative system based on 10 wavelets that searches the Anàlisi de Formes d'Otòlits (AFORO) database and a discriminant method based only on the fifth wavelet. With the exception of paedomorphic species, the results showed that otolith anatomy and morphometry can be used as diagnostic characters distinguishing the three Mediterranean phylogenetic goby lineages (Pomatoschistus or sand-goby lineage, Aphia lineage and Gobius lineage). The main anatomical differences were related to overall shape (square to rhomboid), the development and shape of the postero-dorsal and antero-ventral lobes and the degree of convexity of dorsal and ventral margins. Iterative classifications and discriminant analysis of otolith contour provided very similar results. In both cases, more than 70% of specimens were correctly classified to species and more than 80% to genus. Iterations in the larger AFORO database (including 216 families of teleosts) attained a 100% correct classification at the family level.
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Affiliation(s)
- A Lombarte
- Institut de Ciències del Mar-CSIC, Passeig Marítim 37-48, 08003, Barcelona, Catalonia, Spain
| | - M Miletić
- Energy Institute Hrvoje Pozar, Savka Cesta 163, 10001, Zagreb, Croatia
| | - M Kovačić
- Natural History Museum Rijeka, Lorenzov prolaz 1HR, 51000, Rijeka, Croatia
| | - J L Otero-Ferrer
- Departamento de Ecoloxía e Bioloxía Animal, Campus Universitario de Vigo, Fonte das Abelleiras s/n, 36310, Vigo, Galiza, Spain
| | - V M Tuset
- Institut de Ciències del Mar-CSIC, Passeig Marítim 37-48, 08003, Barcelona, Catalonia, Spain
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Schulz-Mirbach T, Olbinado M, Rack A, Mittone A, Bravin A, Melzer RR, Ladich F, Heß M. In-situ visualization of sound-induced otolith motion using hard X-ray phase contrast imaging. Sci Rep 2018; 8:3121. [PMID: 29449570 PMCID: PMC5814409 DOI: 10.1038/s41598-018-21367-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/30/2018] [Indexed: 11/23/2022] Open
Abstract
Regarding the basics of ear structure-function relationships in fish, the actual motion of the solid otolith relative to the underlying sensory epithelium has rarely been investigated. Otolith motion has been characterized based on a few experimental studies and on approaches using mathematical modeling, which have yielded partially conflicting results. Those studies either predicted a simple back-and-forth motion of the otolith or a shape-dependent, more complex motion. Our study was designed to develop and test a new set-up to generate experimental data on fish otolith motion in-situ. Investigating the basic parameters of otolith motion requires an approach with high spatial and temporal resolution. We therefore used hard X-ray phase contrast imaging (XPCI). We compared two anatomically well-studied cichlid species, Steatocranus tinanti and Etroplus maculatus, which, among other features, differ in the 3D shape of their otoliths. In a water-filled tank, we presented a pure tone of 200 Hz to 1) isolated otoliths embedded in agarose serving as a simple model or 2) to a fish (otoliths in-situ). Our new set-up successfully visualized the motion of otoliths in-situ and therefore paves the way for future studies evaluating the principles of otolith motion.
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Affiliation(s)
- Tanja Schulz-Mirbach
- Ludwig-Maximilians-University Munich, Department Biology II, Zoology, Großhaderner Straße 2, 82152, Planegg-Martinsried, Germany
| | - Margie Olbinado
- European Synchrotron Radiation Facility (ESRF, ID19), 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Alexander Rack
- European Synchrotron Radiation Facility (ESRF, ID19), 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Alberto Mittone
- European Synchrotron Radiation Facility (ESRF, ID17), 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Alberto Bravin
- European Synchrotron Radiation Facility (ESRF, ID17), 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Roland R Melzer
- Bavarian State Collection of Zoology (ZSM), Münchhausenstraße 21, 81247, Munich, Germany
| | - Friedrich Ladich
- University of Vienna, Department of Behavioural Biology, Althanstraße 14, 1090, Vienna, Austria.
| | - Martin Heß
- Ludwig-Maximilians-University Munich, Department Biology II, Zoology, Großhaderner Straße 2, 82152, Planegg-Martinsried, Germany
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Population Dynamics of the Sparid Fish, Argyrops spinifer (Teleostei: Sparidae) in Coastal Waters of the Persian Gulf. IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY, TRANSACTIONS A: SCIENCE 2017. [DOI: 10.1007/s40995-017-0259-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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22
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Jawad LA, Sabatino G, Ibáñez AL, Andaloro F, Battaglia P. Morphology and ontogenetic changes in otoliths of the mesopelagic fishesCeratoscopelus maderensis(Myctophidae),Vinciguerria attenuataandV. poweriae(Phosichthyidae) from the Strait of Messina (Mediterranean Sea). ACTA ZOOL-STOCKHOLM 2017. [DOI: 10.1111/azo.12197] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Giuseppe Sabatino
- Department of Mathematical and Infomatic Sciences; Physical Sciences and Earth Sciences; University of Messina; Messina Italy
| | - Ana L. Ibáñez
- Departamento de Hidrobiología; Universidad Autónoma Metropolitana-Iztapalapa; México City DF México
| | - Franco Andaloro
- STS of Palermo; ISPRA (Institute for Environmental Protection and Research); Palermo Italy
| | - Pietro Battaglia
- Laboratory of Ichthyology and Marine Ecology; ISPRA (Institute for Environmental Protection and Research); Milazzo ME Italy
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Ladich F, Schulz-Mirbach T. Diversity in Fish Auditory Systems: One of the Riddles of Sensory Biology. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00028] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Schulz-Mirbach T, Ladich F. Diversity of Inner Ears in Fishes: Possible Contribution Towards Hearing Improvements and Evolutionary Considerations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:341-91. [DOI: 10.1007/978-3-319-21059-9_16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Sisneros JA, Rogers PH. Directional Hearing and Sound Source Localization in Fishes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:121-55. [DOI: 10.1007/978-3-319-21059-9_7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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26
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What the Toadfish Ear Tells the Toadfish Brain About Sound. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:197-226. [PMID: 26515316 DOI: 10.1007/978-3-319-21059-9_10] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Of the three, paired otolithic endorgans in the ear of teleost fishes, the saccule is the one most often demonstrated to have a major role in encoding frequencies of biologically relevant sounds. The toadfish saccule also encodes sound level and sound source direction in the phase-locked activity conveyed via auditory afferents to nuclei of the ipsilateral octaval column in the medulla. Although paired auditory receptors are present in teleost fishes, binaural processes were believed to be unimportant due to the speed of sound in water and the acoustic transparency of the tissues in water. In contrast, there are behavioral and anatomical data that support binaural processing in fishes. Studies in the toadfish combined anatomical tract-tracing and physiological recordings from identified sites along the ascending auditory pathway to document response characteristics at each level. Binaural computations in the medulla and midbrain sharpen the directional information provided by the saccule. Furthermore, physiological studies in the central nervous system indicated that encoding frequency, sound level, temporal pattern, and sound source direction are important components of what the toadfish ear tells the toadfish brain about sound.
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Ladich F. Peripheral Hearing Structures in Fishes: Diversity and Sensitivity of Catfishes and Cichlids. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:321-40. [DOI: 10.1007/978-3-319-21059-9_15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Vasconcelos RO, Alderks PW, Sisneros JA. Development of Structure and Sensitivity of the Fish Inner Ear. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:291-318. [PMID: 26515320 DOI: 10.1007/978-3-319-21059-9_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Fish represent the largest group of vertebrates and display the greatest diversity of auditory structures. However, studies addressing how the form and function of the auditory system change during development to enhance perception of the acoustic environment are rather sparse in this taxon compared to other vertebrate groups. An ontogenetic perspective of the auditory system in fishes provides a readily testable framework for understanding structure-function relationships. Additionally, studying ancestral models such as fish can convey valuable comparable information across vertebrates, as early developmental events are often evolutionary conserved. This chapter reviews the literature on the morphological development of the fish auditory system, with particular focus on the inner ear structures that evolve from an otic placode during early embryonic development and then continue to undergo differentiation and maturation in the postembryonic phase. Moreover, the chapter provides a systematic overview of how auditory sensitivity develops during ontogeny. Although most studies indicate a developmental improvement in auditory sensitivity, there is considerably species-specific variation. Lastly, the paucity of information and literature concerning the development of auditory capabilities for social communication in fishes is also discussed. Further investigation on the development of structure and function of the fish auditory system is recommended in order to obtain a deeper understanding of how ontogenetic morphological changes in the auditory pathway relate to modifications in acoustic reception, auditory processing, and the capacity to communicate acoustically.
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Affiliation(s)
- Raquel O Vasconcelos
- Institute of Science and Environment, University of Saint Joseph, Macau, S.A.R., China.
| | - Peter W Alderks
- Department of Psychology, University of Washington, Seattle, WA, 98195, USA
| | - Joseph A Sisneros
- Department of Psychology, University of Washington, Seattle, WA, 98195, USA.,Department of Biology, University of Washington, Seattle, WA, 98195, USA
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Alderks PW, Sisneros JA. Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus. PLoS One 2013; 8:e82182. [PMID: 24340003 PMCID: PMC3858275 DOI: 10.1371/journal.pone.0082182] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 10/22/2013] [Indexed: 11/18/2022] Open
Abstract
The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r2 = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or −15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140–150 dB re 1 µPa or −33 to −23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9–2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.
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Affiliation(s)
- Peter W. Alderks
- Department of Psychology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| | - Joseph A. Sisneros
- Department of Psychology, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, United States of America
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30
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Deng X, Wagner HJ, Popper AN. Interspecific Variations of Inner Ear Structure in the Deep-Sea Fish Family Melamphaidae. Anat Rec (Hoboken) 2013; 296:1064-82. [DOI: 10.1002/ar.22703] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 02/02/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Xiaohong Deng
- Department of Biology; Center for Comparative and Evolutionary Biology of Hearing; Neuroscience and Cognitive Science Program, University of Maryland; College Park Maryland
| | - Hans-Joachim Wagner
- Anatomisches Institut, Medizinische Fakultät, University of Tübingen; Tübingen D-72074 Germany
| | - Arthur N. Popper
- Department of Biology; Center for Comparative and Evolutionary Biology of Hearing; Neuroscience and Cognitive Science Program, University of Maryland; College Park Maryland
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31
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Bani A, Poursaeid S, Tuset VM. Comparative morphology of the sagittal otolith in three species of south Caspian gobies. JOURNAL OF FISH BIOLOGY 2013; 82:1321-1332. [PMID: 23557309 DOI: 10.1111/jfb.12073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Accepted: 01/20/2013] [Indexed: 06/02/2023]
Abstract
Sagittal otolith shapes were investigated in order to identify three sympatric species of south Caspian gobies (Caspian goby Neogobius caspius, deepwater goby Ponticola bathybius and bighead goby Ponticola gorlap). The sagittal otoliths in P. bathybius have a rectangular shape and are thick, whereas in N. caspius they are relatively round and thin. In P. gorlap, otoliths have an elongated shape and are relatively thick. The noticeable difference among the otoliths of the three species is the presence of one anterior and one posterior projection in the otoliths of N. caspius and P. gorlap. Among shape indices, form factor (irregularity of surface area), circularity, aspect ratio and rectangularity are the foremost that indicate interspecific variability. The canonical discriminant analysis correctly classifies 94·7% of the original group cases. The overall analyses show the relevance of applying otolith shape for interspecific distinction of the three species of Caspian gobies.
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Affiliation(s)
- A Bani
- Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran.
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Evangelista C, Mills M, Siebeck UE, Collin SP. A comparison of the external morphology of the membranous inner ear in elasmobranchs. J Morphol 2010; 271:483-95. [DOI: 10.1002/jmor.10812] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nedwell JR, Turnpenny AWH, Lovell JM, Edwards B. An investigation into the effects of underwater piling noise on salmonids. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2006; 120:2550-4. [PMID: 17139717 DOI: 10.1121/1.2335573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Underwater piling was undertaken in 2003 in Southampton Water on the South Coast of England. Monitoring was simultaneously undertaken of the waterborne sound from impact and vibropiling and its effects on brown trout in cages at increasing distances from the piling. Brown trout (Salmo trutta) were used as a model for salmon (Salmo salar), which were the species of interest but were not readily available. No obvious signs of trauma that could be attributed to sound exposure were found in any fish examined, from any of the cages. No increase in activity or startle response was seen to vibropiling. Analysis using the dBh, metric indicated that the noise at the nearest cages during impact piling reached levels at which salmon were expected to react strongly. However, the brown trout showed little reaction. An audiogram of the brown trout was measured by the Auditory Brainstem Response method, which indicated that the hearing of the brown trout was less sensitive than that of the salmon. Further analysis indicated that this accounted for the relative lack of reaction, and demonstrated the importance of using the correct species of fish as a model when assessing the effect of noise.
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Affiliation(s)
- Jeremy R Nedwell
- Subacoustech Ltd., Chase Mill, Winchester Road, Bishop's Waltham, Hampshire SO32 1AH, United Kingdom
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35
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Lombarte A, Fortuño JM. Differences in morphological features of the sacculus of the inner ear of two hakes (Merluccius capensisandM. paradoxus, gadiformes) inhabits from different depth of sea. J Morphol 2005; 214:97-107. [DOI: 10.1002/jmor.1052140107] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
The sensory end organs of the inner ear of the lungfish, Protopterus, were examined using scanning and transmission electron microscopy. The utricle has a structure and hair cell orientation pattern that are typical for vertebrates, although the hair cells are unusually large. There are the typical three semicircular canals extending from the utricle, with the typical hair cell orientations, but the lateral canal sensory crista looks like the "hemicrista" of some amphibians and amniotes, lacking a saddle-shaped flare on one wall of the ampulla. Unlike most vertebrates that have the saccule and lagena as two separate pouches ventral to the utricle, the lungfish has a single large ventral pouch that contains a single large pasty otoconial mass. This mass covers two hair cell patches, each like a striola with prominent hair cell ciliary bundles, that are presumed to represent saccular and lagenar maculae. However, these two major sensory patches are not completely separate maculae because they lie within a less densely populated field of smaller hair cells, which forms an extrastriolar region that surrounds and fills the region between the two striolae of higher hair cell density. The more caudal lagenar striola is a vertically elongated stripe with hair cell orientation vectors facing antiparallel on either side of a midline drawn vertically along the macula, resembling the macula lagena of some bony fishes but not of tetrapods. The more rostral saccular striola is a curving band with hair cell orientation vectors facing away from its midline, but because this macula curves in three dimensions, the vectors at the rostral end of this striola are oriented mediolaterally, whereas the vectors on the caudal half of this striola are oriented dorsoventrally. The presence of a macula neglecta was confirmed near the posterior canal as a tiny single patch of a few dozen hair cells with all the cell orientations directed caudally. The ciliary bundles on the cells in the striolar-like regions of all of three otolithic organs average over 80 cilia, a number far greater than for any other fish studied to date. The features of the single sacculolagenar pouch with separate striolar-like regions, the cellular orientation in the otolith organs, and the large cells and ciliary bundles in Protopterus also were observed in specimens of the other extant lungfish genera, Lepidosiren and Neoceratodus.
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Affiliation(s)
- Christopher Platt
- Department of Biology, University of Maryland, College Park, Maryland 20742, USA
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Ramcharitar JU, Deng X, Ketten D, Popper AN. Form and function in the unique inner ear of a teleost: The silver perch (Bairdiella chrysoura). J Comp Neurol 2004; 475:531-9. [PMID: 15236234 DOI: 10.1002/cne.20192] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Members of the teleost family Sciaenidae show significant variation in inner ear and swim bladder morphology as well as in the relationship between the swim bladder and the inner ear. In the silver perch (Bairdiella chrysoura), a Stellifer-group sciaenid, both the saccular and utricular otoliths are enlarged relative to those in other teleosts. Additionally, its swim bladder is two-chambered, and the anterior chamber surrounds the otic capsule and terminates lateral to the saccules. Structure and function of the auditory system of the silver perch were explored by using gross dissections, scanning electron microscopy, CT scan reconstruction, and auditory brainstem response approach. Several morphological specializations of the auditory system of the silver perch were found, including expansion of the utricular and lagenar otoliths, close proximity between the saccules and the utricles, deeply grooved sulci on the saccular otoliths, two-planar saccular sensory epithelia, and a unique orientation pattern of sensory hair cell ciliary bundles on the saccular sensory epithelium. It was determined that the silver perch can detect up to 4 kHz, with lowest auditory thresholds between 600 Hz and 1 kHz. Audition in the silver perch is comparable to that in the goldfish (Carassius auratus), a hearing "specialist." The morphological specializations of the inner ear and swim bladder of the silver perch may be linked to its enhanced hearing capabilities. The findings of this study support the proposal that sciaenids are excellent model species for investigating structure-function relations in the teleost auditory system.
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Eastman JT, Lannoo MJ. Diversification of brain and sense organ morphology in antarctic dragonfishes (Perciformes: Notothenioidei: Bathydraconidae). J Morphol 2003; 258:130-50. [PMID: 14518008 DOI: 10.1002/jmor.10140] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In the subzero shelf waters of Antarctica, fishes of the perciform suborder Notothenioidei dominate the fish fauna and constitute an adaptive radiation and a species flock. The 16 species of dragonfishes of the family Bathydraconidae live from surface waters to nearly 3,000 m and have the greatest overall depth range among notothenioid families. We examined the anatomy and histology of the brain, retina, and cephalic lateral line system of nine bathydraconid species representing 8 of the 11 known genera. We evaluate these data against a cladogram identifying three clades in the family. We provide a detailed drawing of the brain and cranial nerves of Gymnodraco acuticeps and Akarotaxis nudiceps. Bathydraconid brain morphology falls into two categories. Brains of most species are similar to those of generalized perciforms and some basal notothenioids (Class I). However, brains of deep-living bathydraconids (members of the tribe Bathydraconini minus Prionodraco) have a reduced telencephalon and tectum that renders the neural axis visible - the stalked brain morphology (Class II). All bathydraconids have duplex (rod and cone) retinae but there is considerable interspecific variation in the ratio of cones:rods and in the number of cells in the internal nuclear layer. Retinal histology reflects habitat depth but is not tightly coupled to phylogeny. Although the deep-living species of Bathydraconini have rod-dominated retinae, the retinae of some sister species are photopic. An expanded cephalic lateral line system is also characteristic of all members of the Bathydraconini as exemplified by Akarotaxis. This morphology includes large lateral line pores, wide membranous canals, hypertrophied canal neuromasts, and large anterodorsal lateral line nerves, eminentia granulares, and crista cerebellares. The saccular otoliths are also enlarged in members of this tribe. Neural diversification among bathydraconids on the Antarctic shelf has not involved the evolution of sensory specialists. Brain and sense organ morphologies do not approach the specialized condition seen in primary deep-sea fishes or even that of some secondary deep-sea fishes including sympatric non-notothenioids such as liparids (snailfishes) and muraenolepidids (eel cods). The brains and sense organs of bathydraconids, including the deep-living species, reflect their heritage as perciform shorefishes.
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Affiliation(s)
- Joseph T Eastman
- Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701-2979, USA.
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Ladich F, Popper AN. Comparison of the inner ear ultrastructure between teleost fishes using different channels for communication. Hear Res 2001; 154:62-72. [PMID: 11423216 DOI: 10.1016/s0378-5955(01)00217-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The anatomy and ultrastructure of the inner ear of three species of gouramis which differ widely in acoustic behavior were studied using scanning electron microscopy. Of the three species. Trichopsis possess a pectoral sound-producing mechanism while Macropodus and Betta lack sonic organs. The general structure of the inner ear and the shapes of the sensory epithelia are very similar, although they do differ on the posterior part of the saccular macula which is more S-shaped in Trichopsis and Macropodus than in Betta. The maculae on the three species do not differ either in ciliary bundle type (cells with long kinocilia on the periphery of the maculae and cells with short kinocilia in the central region) or in hair cell orientation pattern. Quantitative measurements of hair cell densities and the size of the sensory epithelia of the saccule did not show significant differences between species. Data presented correlate with physiological results from other investigators showing similar auditory sensitivity in Trichopsis and Macropodus. The similarity in structure and function of the inner ears of gouramis on one hand, and the occurrence of sound-generating organs in just one genus, suggests that hearing evolved prior to vocalization and thus acoustic communication in this taxon.
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Affiliation(s)
- F Ladich
- Institute of Zoology, University of Vienna, Austria.
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Abstract
The ability of a fish to interpret acoustic information in its environment is crucial for its survival. Thus, it is important to understand how underwater noise affects fish hearing. In this study, the fathead minnow (Pimephales promelas) was used to examine: (1) the immediate effects of white noise exposure (0.3-4.0 kHz, 142 dB re: 1 microPa) on auditory thresholds and (2) recovery after exposure. Audiograms were measured using the auditory brainstem response protocol and compared to baseline audiograms of fathead minnows not exposed to noise. Immediately after exposure to 24 h of white noise, five out of the eight frequencies tested showed a significantly higher threshold compared to the baseline fish. Recovery was found to depend on both duration of noise exposure and auditory frequency. These results support the hypothesis that the auditory threshold of the fathead minnow can be altered by white noise, especially in its most sensitive hearing range (0.8-2.0 kHz), and provide evidence that these effects can be long term (>14 days).
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Affiliation(s)
- A R Scholik
- Mechanosensory Physiology Laboratory, School of Biological Sciences, University of Kentucky, Lexington, KY 40506, USA.
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41
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Abstract
The masses and the area sizes of the otoliths for the utriculus, sacculus and lagena of 15 species of the Black Sea fish are analyzed. Morphometrical otolith regularities are derived and their functional and ecomorphological explanations are suggested. The otolith regularities are summarized in four otolith rules: (1) the masses of the otoliths gradually increase with the fish growth. (2) The mass ratio of the sacculus and utriculus or the sacculus and lagena otoliths does not change with the fish growth. (3) The ratio between the otolith area s and the otolith mass m is described by the exponential equation s=alpham(2/3). (4) The ratio between the otolith and macula sizes does not change with fish growth. Mathematical modeling of the otolith displacement responses to the acoustic and the instant force stimuli is performed. Based on the modeling the functional and ecomorphological explanations of the otolith regularities are suggested: (1) the greater the otolith mass, the higher the acoustic sensitivity at low frequencies and the sharper the frequency-response curve at its maximum. (2) The separation between maxima of the frequency-response curves for the saccular and lagenar otoliths remains virtually constant with the fish growth. (3) The bottom and littoral fish have better auditory capabilities than the pelagic fish. (4) The sensitivity to vestibular stimuli for greater otoliths is higher but the response is slower. The corresponding acceleration resolution for greater otoliths is higher and the range of accelerations in which the otolith organ can operate is narrower. (5) The relative vestibular sensitivities of the utriculus, sacculus and lagena otolith organs remain constant with fish growth. (6) The otolith organs of the bottom and littoral fish are tuned to different accelerations and possess different functional properties. The otolith organs of pelagic fish are adapted to a limited range of accelerations and are less sensitive to low accelerations as compared to the bottom and littoral fish.
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Affiliation(s)
- D V Lychakov
- Sechenov Institute, Thorez Pr. 44, 194223, St. Petersburg, Russia.
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Lu Z, Popper AN. Morphological polarizations of sensory hair cells in the three otolithic organs of a teleost fish: fluorescent imaging of ciliary bundles. Hear Res 1998; 126:47-57. [PMID: 9872133 DOI: 10.1016/s0378-5955(98)00149-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It has been suggested that the morphological polarity of sensory hair cells in the otolithic organs plays important roles in directional hearing in fish. In this study, we examined the hair cell polarization patterns in the saccule, utricle, and lagena of a teleost fish, the sleeper goby (Dormitator latifrons). In contrast to using traditional scanning electron microscopy, we employed a simple and rapid method that enabled us to map the hair cell polarization patterns using immunocytochemical and confocal imaging techniques. The hair cells in the caudal part of the saccular epithelium are oriented dorsally and ventrally, with some variations in the caudal end. The hair cells in the rostral part have diverse morphological polarizations. The utricular hair cells fall into internal and external groups which have opposing polarizations. The lagenar hair cells are found in anterior and posterior groups with approximately opposite polarizations. The saccular and lagenar epithelia are oriented perpendicular to the horizontal plane of the fish, while the utricular epithelium lies on the horizontal plane. Thus, the sleeper goby's ear is morphologically capable of being a three-dimensional sound detector.
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Affiliation(s)
- Z Lu
- Department of Biology, University of Maryland, College Park 20742-4415, USA.
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Abstract
Ultrastructural variation in some cytoplasmic organelles and synaptic structures is one characteristic distinguishing the types of hair cells in the teleost ear. In this study, we explored differences in mitochondria by analyzing mitochondrial reactivity for cytochrome oxidase (COX) in hair cells of the teleost utricle. The reactivity for COX within mitochondria in the subcuticular compartment directly beneath the cuticular plate differentiated among hair cells in utricles of three teleost species, Carassius auratus, Pantodon buchholzi, and Astronotus ocellatus. Mitochondria in the subcuticular region of hair cells in the striola reacted intensely. Within juxtastriola and extrastriolar hair cells near the striola, mitochondria reacted at a lowered intensity than in striolar hair cells. Subcuticular mitochondria of extrastriolar hair cells located distant from the striola reacted negligibly. The reactivity of mitochondria in other cytoplasmic compartments did not provide similar evidence for distinguishing among teleost hair cells. Mitochondria within intraepithelial branches of the eighth nerve terminals in the different utricular regions reacted to COX histochemistry commensurate with their respective presynaptic hair cells. Branches of sensory afferent neurons innervating striolar hair cells displayed a dense COX reaction. Sensory afferents innervating the extrastriolar hair cells did not display many mitochondria at synapses nor, when present, was the staining as dense. The presynaptic side of the hair cell-afferent nerve synapse usually, but not always, contained reactive mitochondria. The presynaptic side of the efferent nerve-hair cell synapse did not necessarily contain mitochondria. Mitochondria filling the cytoplasm in a type of juxtamacula cell revealed uniformly dense COX reactivity.
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Affiliation(s)
- W M Saidel
- Department of Biology, Rutgers University, Camden, NJ 08102, USA.
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Baird RA, Steyger PS, Schuff NR. Intracellular distributions and putative functions of calcium-binding proteins in the bullfrog vestibular otolith organs. Hear Res 1997; 103:85-100. [PMID: 9007577 DOI: 10.1016/s0378-5955(96)00167-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hair cells in the bullfrog vestibular otolith organs were immunolabeled by monoclonal and polyclonal antisera against calbindin (CaB), calmodulin (CaM), calretinin (CaR), and parvalbumin (PA). S-100, previously shown to immunolabel striolar hair cells in fish vestibular organs, only weakly immunolabeled hair cells in the bullfrog vestibular otolith organs. Immunolabeling was not detected in supporting cells. With the exception of CaR, myelinated axons and unmyelinated nerve terminals were immunolabeled by all of the above antisera. Immunolabeling was seen in all saccular hair cells, although hair cells at the macular margins were immunolabeled more intensely for CaB, CaM, and PA than more centrally located hair cells. As the macula margins are known to be a growth zone, this labeling pattern suggests that marginal hair cells up-regulate their calcium-binding proteins during hair cell development. In the utriculus, immunolabeling for CaM and PA was generally restricted to striolar hair cells. CaR immunolabeling was restricted to the stereociliary array. Immunolabeling for other calcium-binding proteins was generally seen in both the cell body and hair bundles of hair cells, although this labeling was often localized to the stereociliary array and the apical portion of the cell body. CaM and PA immunolabeling in the stereociliary array in saccular and utricular striolar cells suggests a functional role for these proteins in mechanoelectric transduction and adaptation.
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Affiliation(s)
- R A Baird
- R.S. Dow Neurological Sciences Institute, Legacy Good Samaritan Hospital, Portland, OR 97209, USA.
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Lombarte A, Morales-Nin B. Morphology and ultrastructure of saccular otoliths from five species of the genusCoelorinchus (Gadiformes: Macrouridae) from the Southeast Atlantic. J Morphol 1995; 225:179-192. [DOI: 10.1002/jmor.1052250204] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
The ultrastructure of sensory hair cells in the utricle of the cichlid fish, Astronotus ocellatus, the oscar, was studied by transmission electron microscopy of serial ultrathin sections from different regions of the epithelium. Two distinctly different types of hair cell were found, one located in the striolar region of the epithelium and the other in the extrastriolar region. Striolar hair cells have a well-defined perinuclear cisterna located just below the nucleus, and large perinuclear mitochondria. Synaptic bodies of striolar cells are small and located in clusters, while those in extrastriolar cells are relatively large and individually dispersed. The extrastriolar hair cell closely resembles the amniote type II hair cell. On the basis of these data, and consistent with earlier studies, it appears that the striolar hair cells closely resemble amniote type I hair cells in many significant ways. Thus we have called them type I-like cells. The extrastriolar hair cells appear to be typical of eighth nerve mechanoreceptors commonly described for fish and closely resemble the amniote type II hair cell.
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Affiliation(s)
- J S Chang
- Department of Zoology, University of Maryland, College Park 20742
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Yan HY, Saidel WM, Chang JS, Presson JC, Popper AN. Sensory hair cells of a fish ear: evidence of multiple types based on ototoxicity sensitivity. Proc Biol Sci 1991; 245:133-8. [PMID: 1682936 DOI: 10.1098/rspb.1991.0099] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sensory hair cells from the striolar region (striolar hair cells) of the utricle and the lagena of the ear of a teleost fish Astronotus ocellatus (Cuvier) ear are sensitive to gentamicin sulphate, an ototoxic drug. In contrast, sensory hair cells from outside the striolar region (extra-striolar hair cells) are not sensitive to gentamicin. These data, combined with results from studies showing different ultrastructural features and different immunoreactivity to a calcium binding protein, S-100, lead to the suggestion that there are distinguishable types of hair cells in these endorgans. These results add to the increasing evidence that classifying the sensory hair cells of fish ears only as the traditional 'vestibular type II' may be inadequate for properly understanding structure and function of the fish ear.
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Affiliation(s)
- H Y Yan
- Department of Zoology, University of Maryland, College Park 20742
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50
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Saidel WM, Popper AN, Chang JS. Spatial and morphological differentiation of trigger zones in afferent fibers to the teleost utricle. J Comp Neurol 1990; 302:629-42. [PMID: 1702121 DOI: 10.1002/cne.903020317] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A morphological correlate of the trigger site (the locus of action potential initiation) was identified in afferent axons of the utricle in the ear of two species of teleost fish. These sites were identified by the ferric-ferrocyanide (Prussian blue) cytochemical procedure and they were correlated with the geometries of afferent intraepithelial arbors as visualized by means of a silver stain. The intraepithelial arbors of afferent fibers show regional distributions that correlate with axon diameter and Prussian blue staining. Afferent axons with diameters greater than 4-5 microns only innervate the striola regions of the epithelium and terminate as one of two distinct types of intraepithelial arbors. Afferent axons with diameters smaller than 4 microns are ubiquitously distributed throughout the epithelium. Arbors that stained by Prussian blue within the utricular epithelium are restricted to the striolar regions. These arbors possess nodal-like membrane in different branches as postsynaptic membrane. Afferents that innervate hair cells in the extrastriolar epithelial regions stained with Prussian blue only at the extraepithelial terminal heminode. The postsynaptic membrane of these afferents is passive or dendritic-like.
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Affiliation(s)
- W M Saidel
- Department of Zoology, University of Maryland, College Park 20742
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