The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles or Weber's ossicles. The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi. The structure itself consists of a set of minute bones that originate from the first few vertebrae to develop in an embryonic ostariophysan. These bones grow to physically connect the auditory system, specifically the inner ear, to the swim bladder.[1][2] The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone.
The generalized structure of the Weberian apparatus is akin to a skeletal complex of bones and ossicles that are physically connected to the labyrinth auditory complex anteriorly and the anteriormost region of the swim bladder posteriorly. The entire structure is derived from skeletal elements of the first four vertebrae. The involved elements include: the supraneural bones of the skull; modified neural arch bones, specifically the paired claustra and the scaphia; the intercalarium and the lateral processes; the tripus; the os suspensorium from the fourth vertebra; the parapophysis of vertebra number five including the vertebra itself, plus the vertebra's corresponding pleural rib. In addition, a structure composed of fused neural spines form the dorsal most part of the Weberian apparatus. Together, the structure interacts anteriorly with the lagenar otolith set within the skull and posteriorly with the swim bladder via the pleural rib. Postero-ventrally, it is the tripus, the os suspensorium and the third rib that interact directly with the anterior chamber of the swim bladder.[1]
The Weberian apparatus functions by transmitting auditory signals straight from the gas bladder, through the Weberian ossicles and then straight into the labyrinth structures of the inner ear. The structure essentially acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. With the added function of the swim bladder as a Resonance chamber, signals are amplified to noticeable levels. [2]
Embryologyedit
Embryonic analysis of Weberian apparatuses of the taxon Brycon has shed some light on the development of the structure itself. The Weberian apparatus elements form from the fully distinguishable first five vertebrae of the individual. The supraneural starts as an element of the skull. The claustra and the scaphia develop from expanded elements of the neural arch of the first vertebra (V1). From the second vertebra (V2), the intercalarum and the vertebra's lateral process are reduced and clump together. The plural rib (R1) of the third vertebra (V3) shrinks and moves somewhat ventrally, forming the tripus from a vertebral parapophysis fusing with the pleural rib. The os suspensorium bone of the fourth vertebra (V4) somewhat retains its shape, developing from the pleural rib of the vertebra (R2). The remaining elements of the fifth vertebra (V5), the parapophysis and the articulating rib (R3), including the vertebra itself form the posterior structure of the Weberian apparatus. The neural spines of the first four vertebrae fuse and compress, forming one of the major structures of the apparatus.[1][2]
Study of the embryology of the Weberian apparatus has since been conducted on various other ostariophysan species, the outcomes of which have resulted in various interpretations of the development (and thus the homology) of the structures that form the structure. Specific studies have been done on the Weberian apparatuses of a few select taxa, including Danio rerio,[3]Rhaphiodon vulpinus[4] and Corydoras paleatus.[5]
Evolutionary historyedit
The earliest recorded incidence of a Weberian apparatus is from the fossil fish Santanichthys diasii dating from the Early Cretaceous of Northeastern Brazil. In the aforementioned taxon, the Weberian apparatus is fairly developed; there is a distinguishable intercalarium and a tripus which articulate with the second and third vertebrae respectively. A scaphium can be seen in at least two specimens. The neural arch of the third vertebra has already broadened, almost similar to that of modern ostariophysans. The claustrum, an element in modern apparati, is noticeably absent from the Weberian apparatus of S. diasii. Only the first four vertebrae are involved in the Weberian apparatus of Santanichthys; There are no signs of involvement from the elements of the fifth vertebra unlike in modern otophysans.[6] An important feature within the formation of the Weberian apparatus, which is a synapomorphy of the Otocephala, is the attachment of the anterior Pleural cavity(rib) to the Swim bladder. Another crucial feature is the anterior otophysic diverticula of the swim bladder and contacting the inner ear, seen in extant Clupeiformes. There is also a relationship between the interossicular ligament and the swim bladder that it originated from the swim bladder diverticulum. This was shown by comparing the fiber of the ligament and the tunica externa of the swim bladder that have the same histological composition of elastin and icthyocoll (a specific type I collagen), as established in a research by Rui Diogo.[7]
Etymologyedit
Ernst H. Weber, who first described the structure named after him.
The Weberian apparatus is named after the German anatomist and physiologist Ernst Heinrich Weber (1795 – 1878). The apparatus was first described in detail by Weber. Only four bones were identified, specifically the claustrum, scaphium, intercalarium and tripus. Together, these elements were hypothesized to play a part in auditory functions.[8] Over the years, other functions have been proposed and discarded. Hydrostatic regulation was one of the early alternative suggestions for the function of the apparatus.[9]
^ abcRosen, Donn Eric; P. Humphry Greenwood (1970-08-26). "Origin of the Weberian Apparatus and the Relationships of the Ostariophysan and Gonorynchiform Fishes". American Museum Novitates (2428). New York, New York, USA: American Museum of Natural History.
^ abcGrande, Terry; Mario de Pinna (2004). G. Arratia & A. Tintori (ed.). The evolution of the Weberian apparatus: A phylogenetic perspective(PDF). Mesozoic Fishes 3 – Systematics, Paleoenvironments and Biodiversity. München, Germany: Verlag. pp. 429–448. ISBN3-89937-053-8.
^Grande, Terry; Bruce Young (2004). "The ontogeny and homology of the Weberian apparatus in the zebrafish Danio rerio (Ostariophysi: Cypriniformes)". Zoological Journal of the Linnean Society. 140 (2). The Linnaean Society: 241–254. doi:10.1111/j.1096-3642.2003.00097.x.
^Nelson, Edward M. (2005-02-06). "The swim bladder and Weberian apparatus of Rhaphiodon vulpinus Agassiz, with notes on some additional morphological features". Journal of Morphology. 84 (34). Wiley-Liss, Inc., A Wiley Company: 495–523. doi:10.1002/jmor.1050840306. PMID 18151916. S2CID 30275470.
^Coburn, Miles M.; Paul G. Grubach (1998-05-01). "Ontogeny of the Weberian Apparatus in the Armored Catfish Corydoras paleatus (Siluriformes: Callichthyidae)". Copeia. 1998 (2). American Society of Ichthyologists and Herpetologists: 301–311. doi:10.2307/1447426. JSTOR 1447426.
^Filleul, Arnaud; John G. Maisey (2004-10-28). "Redescription of Santanichthys diasii (Otophysi, Characiformes) from the Albian of the Santana Formation and Comments on Its Implications for Otophysan Relationships". American Museum Novitates (3455). New York, NY, USA: American Museum of Natural History: 1. doi:10.1206/0003-0082(2004)455<0001:ROSDOC>2.0.CO;2.
^Rui, Diogo. "Origin, Evolution and Homologies of the Weberian Apparatus: A New Insight" (PDF). Int. J. Morphol. 2: 333–354.
^Weber, Ernst Heinrich (1820). De aure et auditu hominis et animalium. I — De aure animalium aquatilium (in Latin). Leipzig, Germany: Gerhard Fleischer.
^Krumholz, Louis A. (1943-03-31). "A Comparative Study of the Weberian Ossicles in North American Ostariophysine Fishes". Copeia. 1943 (1). American Society of Ichthyologists and Herpetologists: 33–40. doi:10.2307/1437878. JSTOR 1437878.
Bibliographyedit
Weber, Ernst Heinrich (1820). De aure et auditu hominis et animalium. I — De aure animalium aquatilium (in Latin). Leipzig, Germany: Gerhard Fleischer.
Grande, Terry; Mario de Pinna (2004). G. Arratia & A. Tintori (ed.). The evolution of the Weberian apparatus: A phylogenetic perspective(PDF). Mesozoic Fishes 3 – Systematics, Paleoenvironments and Biodiversity. München, Germany: Verlag. pp. 429–448. ISBN3-89937-053-8.
Manley, Geoffrey A.; Arthur N. Popper; Richard R. Fay (2004). "Chapter 5: Evolution of Single- and Multiple- Ossicle Ears in Fishes and Tetrapods". Evolution of the Vertebrate Auditory System. Chapter by Jennifer A. Clack and Edgar Allin. Springer. p. 415. ISBN978-0387210933.
Bird, Nathan C.; L. Patricia Hernandez (2007-06-25). "Morphological variation in the Weberian apparatus of Cypriniformes". Journal of Morphology. 268 (9). Wiley-Liss, Inc., A Wiley Company: 735–757. doi:10.1002/jmor.10550. PMID 17591731. S2CID 29393291. Archived from the original on 2013-01-05.
January 01, 1970
weberian, apparatus, anatomical, structure, that, connects, swim, bladder, auditory, system, fishes, belonging, superorder, ostariophysi, when, fully, developed, adult, fish, elements, apparatus, sometimes, collectively, referred, weberian, ossicles, weber, os. The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi When it is fully developed in adult fish the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles or Weber s ossicles The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi The structure itself consists of a set of minute bones that originate from the first few vertebrae to develop in an embryonic ostariophysan These bones grow to physically connect the auditory system specifically the inner ear to the swim bladder 1 2 The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone Weberian apparatus and air bladder of a carp Contents 1 Structural anatomy and function 2 Embryology 3 Evolutionary history 4 Etymology 5 See also 6 References 7 BibliographyStructural anatomy and function editThe generalized structure of the Weberian apparatus is akin to a skeletal complex of bones and ossicles that are physically connected to the labyrinth auditory complex anteriorly and the anteriormost region of the swim bladder posteriorly The entire structure is derived from skeletal elements of the first four vertebrae The involved elements include the supraneural bones of the skull modified neural arch bones specifically the paired claustra and the scaphia the intercalarium and the lateral processes the tripus the os suspensorium from the fourth vertebra the parapophysis of vertebra number five including the vertebra itself plus the vertebra s corresponding pleural rib In addition a structure composed of fused neural spines form the dorsal most part of the Weberian apparatus Together the structure interacts anteriorly with the lagenar otolith set within the skull and posteriorly with the swim bladder via the pleural rib Postero ventrally it is the tripus the os suspensorium and the third rib that interact directly with the anterior chamber of the swim bladder 1 The Weberian apparatus functions by transmitting auditory signals straight from the gas bladder through the Weberian ossicles and then straight into the labyrinth structures of the inner ear The structure essentially acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone With the added function of the swim bladder as a Resonance chamber signals are amplified to noticeable levels 2 Embryology editEmbryonic analysis of Weberian apparatuses of the taxon Brycon has shed some light on the development of the structure itself The Weberian apparatus elements form from the fully distinguishable first five vertebrae of the individual The supraneural starts as an element of the skull The claustra and the scaphia develop from expanded elements of the neural arch of the first vertebra V1 From the second vertebra V2 the intercalarum and the vertebra s lateral process are reduced and clump together The plural rib R1 of the third vertebra V3 shrinks and moves somewhat ventrally forming the tripus from a vertebral parapophysis fusing with the pleural rib The os suspensorium bone of the fourth vertebra V4 somewhat retains its shape developing from the pleural rib of the vertebra R2 The remaining elements of the fifth vertebra V5 the parapophysis and the articulating rib R3 including the vertebra itself form the posterior structure of the Weberian apparatus The neural spines of the first four vertebrae fuse and compress forming one of the major structures of the apparatus 1 2 Study of the embryology of the Weberian apparatus has since been conducted on various other ostariophysan species the outcomes of which have resulted in various interpretations of the development and thus the homology of the structures that form the structure Specific studies have been done on the Weberian apparatuses of a few select taxa including Danio rerio 3 Rhaphiodon vulpinus 4 and Corydoras paleatus 5 Evolutionary history editThe earliest recorded incidence of a Weberian apparatus is from the fossil fish Santanichthys diasii dating from the Early Cretaceous of Northeastern Brazil In the aforementioned taxon the Weberian apparatus is fairly developed there is a distinguishable intercalarium and a tripus which articulate with the second and third vertebrae respectively A scaphium can be seen in at least two specimens The neural arch of the third vertebra has already broadened almost similar to that of modern ostariophysans The claustrum an element in modern apparati is noticeably absent from the Weberian apparatus of S diasii Only the first four vertebrae are involved in the Weberian apparatus of Santanichthys There are no signs of involvement from the elements of the fifth vertebra unlike in modern otophysans 6 An important feature within the formation of the Weberian apparatus which is a synapomorphy of the Otocephala is the attachment of the anterior Pleural cavity rib to the Swim bladder Another crucial feature is the anterior otophysic diverticula of the swim bladder and contacting the inner ear seen in extant Clupeiformes There is also a relationship between the interossicular ligament and the swim bladder that it originated from the swim bladder diverticulum This was shown by comparing the fiber of the ligament and the tunica externa of the swim bladder that have the same histological composition of elastin and icthyocoll a specific type I collagen as established in a research by Rui Diogo 7 Etymology edit nbsp Ernst H Weber who first described the structure named after him The Weberian apparatus is named after the German anatomist and physiologist Ernst Heinrich Weber 1795 1878 The apparatus was first described in detail by Weber Only four bones were identified specifically the claustrum scaphium intercalarium and tripus Together these elements were hypothesized to play a part in auditory functions 8 Over the years other functions have been proposed and discarded Hydrostatic regulation was one of the early alternative suggestions for the function of the apparatus 9 See also editCyprinidaeReferences edit a b c Rosen Donn Eric P Humphry Greenwood 1970 08 26 Origin of the Weberian Apparatus and the Relationships of the Ostariophysan and Gonorynchiform Fishes American Museum Novitates 2428 New York New York USA American Museum of Natural History a b c Grande Terry Mario de Pinna 2004 G Arratia amp A Tintori ed The evolution of the Weberian apparatus A phylogenetic perspective PDF Mesozoic Fishes 3 Systematics Paleoenvironments and Biodiversity Munchen Germany Verlag pp 429 448 ISBN 3 89937 053 8 Grande Terry Bruce Young 2004 The ontogeny and homology of the Weberian apparatus in the zebrafish Danio rerio Ostariophysi Cypriniformes Zoological Journal of the Linnean Society 140 2 The Linnaean Society 241 254 doi 10 1111 j 1096 3642 2003 00097 x Nelson Edward M 2005 02 06 The swim bladder and Weberian apparatus of Rhaphiodon vulpinus Agassiz with notes on some additional morphological features Journal of Morphology 84 34 Wiley Liss Inc A Wiley Company 495 523 doi 10 1002 jmor 1050840306 PMID 18151916 S2CID 30275470 Coburn Miles M Paul G Grubach 1998 05 01 Ontogeny of the Weberian Apparatus in the Armored Catfish Corydoras paleatus Siluriformes Callichthyidae Copeia 1998 2 American Society of Ichthyologists and Herpetologists 301 311 doi 10 2307 1447426 JSTOR 1447426 Filleul Arnaud John G Maisey 2004 10 28 Redescription of Santanichthys diasii Otophysi Characiformes from the Albian of the Santana Formation and Comments on Its Implications for Otophysan Relationships American Museum Novitates 3455 New York NY USA American Museum of Natural History 1 doi 10 1206 0003 0082 2004 455 lt 0001 ROSDOC gt 2 0 CO 2 Rui Diogo Origin Evolution and Homologies of the Weberian Apparatus A New Insight PDF Int J Morphol 2 333 354 Weber Ernst Heinrich 1820 De aure et auditu hominis et animalium I De aure animalium aquatilium in Latin Leipzig Germany Gerhard Fleischer Krumholz Louis A 1943 03 31 A Comparative Study of the Weberian Ossicles in North American Ostariophysine Fishes Copeia 1943 1 American Society of Ichthyologists and Herpetologists 33 40 doi 10 2307 1437878 JSTOR 1437878 Bibliography editWeber Ernst Heinrich 1820 De aure et auditu hominis et animalium I De aure animalium aquatilium in Latin Leipzig Germany Gerhard Fleischer Grande Terry Mario de Pinna 2004 G Arratia amp A Tintori ed The evolution of the Weberian apparatus A phylogenetic perspective PDF Mesozoic Fishes 3 Systematics Paleoenvironments and Biodiversity Munchen Germany Verlag pp 429 448 ISBN 3 89937 053 8 Manley Geoffrey A Arthur N Popper Richard R Fay 2004 Chapter 5 Evolution of Single and Multiple Ossicle Ears in Fishes and Tetrapods Evolution of the Vertebrate Auditory System Chapter by Jennifer A Clack and Edgar Allin Springer p 415 ISBN 978 0387210933 Bird Nathan C L Patricia Hernandez 2007 06 25 Morphological variation in the Weberian apparatus of Cypriniformes Journal of Morphology 268 9 Wiley Liss Inc A Wiley Company 735 757 doi 10 1002 jmor 10550 PMID 17591731 S2CID 29393291 Archived from the original on 2013 01 05 Retrieved from https en wikipedia org w index php title Weberian apparatus amp oldid 1157570860, wikipedia, wiki, book, books, library,
