Morphometric analysis of ears in two families of pinnipeds
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 2001 Pinniped (seal and sea lion) auditory systems operate in two acoustically distinct environments, air and wate...
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Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
2001
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3038 2023-05-15T16:05:23+02:00 Morphometric analysis of ears in two families of pinnipeds Marsh, Sarah Elizabeth 2001-08 application/pdf https://hdl.handle.net/1912/3038 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/3038 doi:10.1575/1912/3038 doi:10.1575/1912/3038 Pinnipedia Seals Hearing Thesis 2001 ftwhoas https://doi.org/10.1575/1912/3038 2022-05-28T22:57:49Z Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 2001 Pinniped (seal and sea lion) auditory systems operate in two acoustically distinct environments, air and water. Piniped species differ in how much time they typically spend in water. They therefore offer an exceptional opportunity to investigate aquatic versus terrestrial hearing mechanisms. The Otariidae (sea lions and fur seals) generally divide their time evenly between land and water and have several adaptations; e.g. external pinnae, related to this lifestyle. Phocidae (true seals) spend the majority of their time in water; they lack external pinnae and have well developed ear canal valves. Differences in hearing ranges and sensitivities have been reported recently for members of both of these familes (Kastak, D., Schusterman, RJ., 1998. Low frequency amphibious hearing in pinnipeds. J. Acoust. Soc. Am. 1303,2216- 2228.; Moore, P.W.B., Schusterman, RJ., 1987. Audiometric assessment of northern fur seals, Callorhinus ursinus. Mar. Mamm. Sci. 3,31-53.). In this project, the ear anatomy of three species of pinnipeds: an otariid, the California sea lion (Zalophus californianus), and two phocids, the northern elephant seal (Mirounga angustirostris) and the harbor seal (Phoca vitulina), was examined using computerized tomography (CT scans) and gross dissection. Thee-dimensional reconstructions of the heads and ears from CT data were used to determine interaural dimensions and ossicular chain morphometrics. Ossicular weights and densities were measured conventionally. Results strongly support a canalcentric system for pinniped sound reception and localization. Further, true seals show adaptations for aquatic high frequency specialization. I was supported by an NDSEG fellowship from ONR. Thesis Elephant Seal harbor seal Phoca vitulina Callorhinus ursinus Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Woods Hole, MA |
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Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
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ftwhoas |
language |
English |
topic |
Pinnipedia Seals Hearing |
spellingShingle |
Pinnipedia Seals Hearing Marsh, Sarah Elizabeth Morphometric analysis of ears in two families of pinnipeds |
topic_facet |
Pinnipedia Seals Hearing |
description |
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 2001 Pinniped (seal and sea lion) auditory systems operate in two acoustically distinct environments, air and water. Piniped species differ in how much time they typically spend in water. They therefore offer an exceptional opportunity to investigate aquatic versus terrestrial hearing mechanisms. The Otariidae (sea lions and fur seals) generally divide their time evenly between land and water and have several adaptations; e.g. external pinnae, related to this lifestyle. Phocidae (true seals) spend the majority of their time in water; they lack external pinnae and have well developed ear canal valves. Differences in hearing ranges and sensitivities have been reported recently for members of both of these familes (Kastak, D., Schusterman, RJ., 1998. Low frequency amphibious hearing in pinnipeds. J. Acoust. Soc. Am. 1303,2216- 2228.; Moore, P.W.B., Schusterman, RJ., 1987. Audiometric assessment of northern fur seals, Callorhinus ursinus. Mar. Mamm. Sci. 3,31-53.). In this project, the ear anatomy of three species of pinnipeds: an otariid, the California sea lion (Zalophus californianus), and two phocids, the northern elephant seal (Mirounga angustirostris) and the harbor seal (Phoca vitulina), was examined using computerized tomography (CT scans) and gross dissection. Thee-dimensional reconstructions of the heads and ears from CT data were used to determine interaural dimensions and ossicular chain morphometrics. Ossicular weights and densities were measured conventionally. Results strongly support a canalcentric system for pinniped sound reception and localization. Further, true seals show adaptations for aquatic high frequency specialization. I was supported by an NDSEG fellowship from ONR. |
format |
Thesis |
author |
Marsh, Sarah Elizabeth |
author_facet |
Marsh, Sarah Elizabeth |
author_sort |
Marsh, Sarah Elizabeth |
title |
Morphometric analysis of ears in two families of pinnipeds |
title_short |
Morphometric analysis of ears in two families of pinnipeds |
title_full |
Morphometric analysis of ears in two families of pinnipeds |
title_fullStr |
Morphometric analysis of ears in two families of pinnipeds |
title_full_unstemmed |
Morphometric analysis of ears in two families of pinnipeds |
title_sort |
morphometric analysis of ears in two families of pinnipeds |
publisher |
Massachusetts Institute of Technology and Woods Hole Oceanographic Institution |
publishDate |
2001 |
url |
https://hdl.handle.net/1912/3038 |
genre |
Elephant Seal harbor seal Phoca vitulina Callorhinus ursinus |
genre_facet |
Elephant Seal harbor seal Phoca vitulina Callorhinus ursinus |
op_source |
doi:10.1575/1912/3038 |
op_relation |
WHOI Theses https://hdl.handle.net/1912/3038 doi:10.1575/1912/3038 |
op_doi |
https://doi.org/10.1575/1912/3038 |
op_publisher_place |
Woods Hole, MA |
_version_ |
1766401273522814976 |