Buoyancy adaptations in a swim‐bladderless Antarctic fish
Abstract The endemic Antarctic teleosts of the suborder Notothenioidei are bottom dwellers. They lack swim bladders, are heavier than seawater, and feed on or near the bottom. The midwaters surrounding the Antarctic continent are productive and underutilized by fishes. There is an evolutionary trend...
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crwiley:10.1002/jmor.1051670108 2024-06-23T07:47:41+00:00 Buoyancy adaptations in a swim‐bladderless Antarctic fish Eastman, Joseph T. DeVries, Arthur L. 1981 http://dx.doi.org/10.1002/jmor.1051670108 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.1051670108 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.1051670108 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Morphology volume 167, issue 1, page 91-102 ISSN 0362-2525 1097-4687 journal-article 1981 crwiley https://doi.org/10.1002/jmor.1051670108 2024-06-11T04:41:42Z Abstract The endemic Antarctic teleosts of the suborder Notothenioidei are bottom dwellers. They lack swim bladders, are heavier than seawater, and feed on or near the bottom. The midwaters surrounding the Antarctic continent are productive and underutilized by fishes. There is an evolutionary trend toward pelagism in some notothenioids. We discovered that the largest Antarctic fish, Dissostichus mawsoni , was neutrally buoyant. Attainment of neutral buoyancy was associated with specializations of the skeletal, integumentary, muscular, and digestive systems. The skeleton had a low mineral content and contained considerable cartilage. Scales were also incompletely mineralized. Static lift was obtained from extensive lipid (mostly triglyceride) deposits. A 2–8 mm subcutaneous lipid layer accounted for 4.7% of the body weight. White muscle also contained much lipid–23% on a dry weight basis, or 4.8% of the body weight. Microscopic examination suggested that the liver was active in lipid metabolism, although it was not an organ of buoyancy. Stellate (perisinusoidal) cells with many lipid droplets were a very prominent cytological component of the liver. These specializations made Dissostichus neutrally buoyant and capable of inhabiting the food‐rich Antarctic midwaters. Article in Journal/Newspaper Antarc* Antarctic Wiley Online Library Antarctic The Antarctic Journal of Morphology 167 1 91 102 |
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Wiley Online Library |
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language |
English |
description |
Abstract The endemic Antarctic teleosts of the suborder Notothenioidei are bottom dwellers. They lack swim bladders, are heavier than seawater, and feed on or near the bottom. The midwaters surrounding the Antarctic continent are productive and underutilized by fishes. There is an evolutionary trend toward pelagism in some notothenioids. We discovered that the largest Antarctic fish, Dissostichus mawsoni , was neutrally buoyant. Attainment of neutral buoyancy was associated with specializations of the skeletal, integumentary, muscular, and digestive systems. The skeleton had a low mineral content and contained considerable cartilage. Scales were also incompletely mineralized. Static lift was obtained from extensive lipid (mostly triglyceride) deposits. A 2–8 mm subcutaneous lipid layer accounted for 4.7% of the body weight. White muscle also contained much lipid–23% on a dry weight basis, or 4.8% of the body weight. Microscopic examination suggested that the liver was active in lipid metabolism, although it was not an organ of buoyancy. Stellate (perisinusoidal) cells with many lipid droplets were a very prominent cytological component of the liver. These specializations made Dissostichus neutrally buoyant and capable of inhabiting the food‐rich Antarctic midwaters. |
format |
Article in Journal/Newspaper |
author |
Eastman, Joseph T. DeVries, Arthur L. |
spellingShingle |
Eastman, Joseph T. DeVries, Arthur L. Buoyancy adaptations in a swim‐bladderless Antarctic fish |
author_facet |
Eastman, Joseph T. DeVries, Arthur L. |
author_sort |
Eastman, Joseph T. |
title |
Buoyancy adaptations in a swim‐bladderless Antarctic fish |
title_short |
Buoyancy adaptations in a swim‐bladderless Antarctic fish |
title_full |
Buoyancy adaptations in a swim‐bladderless Antarctic fish |
title_fullStr |
Buoyancy adaptations in a swim‐bladderless Antarctic fish |
title_full_unstemmed |
Buoyancy adaptations in a swim‐bladderless Antarctic fish |
title_sort |
buoyancy adaptations in a swim‐bladderless antarctic fish |
publisher |
Wiley |
publishDate |
1981 |
url |
http://dx.doi.org/10.1002/jmor.1051670108 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.1051670108 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.1051670108 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Journal of Morphology volume 167, issue 1, page 91-102 ISSN 0362-2525 1097-4687 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/jmor.1051670108 |
container_title |
Journal of Morphology |
container_volume |
167 |
container_issue |
1 |
container_start_page |
91 |
op_container_end_page |
102 |
_version_ |
1802651839692275712 |