Weberian apparatus

Source: Wikipedia, the free encyclopedia.
Weberian apparatus and air-bladder of a carp

The Weberian apparatus is an anatomical structure that connects the

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.

Structural anatomy and function

The generalized structure of the Weberian apparatus is akin to a skeletal complex of bones and ossicles that are physically connected to the

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

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

Rhaphiodon vulpinus[4] and Corydoras paleatus.[5]

Evolutionary history

The earliest recorded incidence of a Weberian apparatus is from the fossil fish

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

Ernst H. Weber
, who first described the structure named after him.

The Weberian apparatus is named after the

Hydrostatic regulation was one of the early alternative suggestions for the function of the apparatus.[9]

See also

References

  1. ^ 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.
  2. ^
    ISBN 3-89937-053-8
    .
  3. doi:10.1111/j.1096-3642.2003.00097.x
    .
  4. S2CID 30275470
    .
  5. JSTOR 1447426
    .
  6. doi:10.1206/0003-0082(2004)455<0001:ROSDOC>2.0.CO;2
    .
  7. ^ Rui, Diogo. "Origin, Evolution and Homologies of the Weberian Apparatus: A New Insight" (PDF). Int. J. Morphol. 2: 333–354.
  8. ^ Weber, Ernst Heinrich (1820). De aure et auditu hominis et animalium. I — De aure animalium aquatilium (in Latin). Leipzig, Germany: Gerhard Fleischer.
  9. JSTOR 1437878
    .

Bibliography
Retrieved from "https://en.wikipedia.org/w/index.php?title=Weberian_apparatus&oldid=1157570860"