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Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales.

Publication ,  Journal Article
Thornton, SW; Mclellan, WA; Rommel, SA; Dillaman, RM; Nowacek, DP; Koopman, HN; Pabst, DA
Published in: Anatomical record (Hoboken, N.J. : 2007)
July 2015

Odontocete echolocation clicks are generated by pneumatically driven phonic lips within the nasal passage, and propagated through specialized structures within the forehead. This study investigated the highly derived echolocation structures of the pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales through careful dissections (N = 18 K. breviceps, 6 K. sima) and histological examinations (N = 5 K. breviceps). This study is the first to show that the entire kogiid sound production and transmission pathway is acted upon by complex facial muscles (likely derivations of the m. maxillonasolabialis). Muscles appear capable of tensing and separating the solitary pair of phonic lips, which would control echolocation click frequencies. The phonic lips are enveloped by the "vocal cap," a morphologically complex, connective tissue structure unique to kogiids. Extensive facial muscles appear to control the position of this structure and its spatial relationship to the phonic lips. The vocal cap's numerous air crypts suggest that it may reflect sounds. Muscles encircling the connective tissue case that surrounds the spermaceti organ may change its shape and/or internal pressure. These actions may influence the acoustic energy transmitted from the phonic lips, through this lipid body, to the melon. Facial and rostral muscles act upon the length of the melon, suggesting that the sound "beam" can be focused as it travels through the melon and into the environment. This study suggests that the kogiid echolocation system is highly tunable. Future acoustic studies are required to test these hypotheses and gain further insight into the kogiid echolocation system.

Duke Scholars

Published In

Anatomical record (Hoboken, N.J. : 2007)

DOI

EISSN

1932-8494

ISSN

1932-8486

Publication Date

July 2015

Volume

298

Issue

7

Start / End Page

1301 / 1326

Related Subject Headings

  • Sperm Whale
  • Nose
  • Male
  • Female
  • Echolocation
  • Animals
  • Anatomy & Morphology
  • 3104 Evolutionary biology
  • 3101 Biochemistry and cell biology
  • 11 Medical and Health Sciences
 

Citation

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Thornton, S. W., Mclellan, W. A., Rommel, S. A., Dillaman, R. M., Nowacek, D. P., Koopman, H. N., & Pabst, D. A. (2015). Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales. Anatomical Record (Hoboken, N.J. : 2007), 298(7), 1301–1326. https://doi.org/10.1002/ar.23168
Thornton, Steven W., William A. Mclellan, Sentiel A. Rommel, Richard M. Dillaman, Douglas P. Nowacek, Heather N. Koopman, and D Ann Pabst. “Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales.Anatomical Record (Hoboken, N.J. : 2007) 298, no. 7 (July 2015): 1301–26. https://doi.org/10.1002/ar.23168.
Thornton SW, Mclellan WA, Rommel SA, Dillaman RM, Nowacek DP, Koopman HN, et al. Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales. Anatomical record (Hoboken, NJ : 2007). 2015 Jul;298(7):1301–26.
Thornton, Steven W., et al. “Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales.Anatomical Record (Hoboken, N.J. : 2007), vol. 298, no. 7, July 2015, pp. 1301–26. Epmc, doi:10.1002/ar.23168.
Thornton SW, Mclellan WA, Rommel SA, Dillaman RM, Nowacek DP, Koopman HN, Pabst DA. Morphology of the Nasal Apparatus in Pygmy (Kogia Breviceps) and Dwarf (K. Sima) Sperm Whales. Anatomical record (Hoboken, NJ : 2007). 2015 Jul;298(7):1301–1326.
Journal cover image

Published In

Anatomical record (Hoboken, N.J. : 2007)

DOI

EISSN

1932-8494

ISSN

1932-8486

Publication Date

July 2015

Volume

298

Issue

7

Start / End Page

1301 / 1326

Related Subject Headings

  • Sperm Whale
  • Nose
  • Male
  • Female
  • Echolocation
  • Animals
  • Anatomy & Morphology
  • 3104 Evolutionary biology
  • 3101 Biochemistry and cell biology
  • 11 Medical and Health Sciences