Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina )
Food intake, mass, fat, locomotor activity, and thyroid hormones were monitored in five captive harbour seals (Phoca vitulina) over an 18-month period. Food intake ranged from anorexia to 11% body weight, with changes in body mass reaching 59% in the males. Food intake was negatively related to chan...
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1991
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crcansciencepubl:10.1139/z91-348 2024-04-07T07:55:27+00:00 Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) Renouf, Deane Noseworthy, Elizabeth 1991 http://dx.doi.org/10.1139/z91-348 http://www.nrcresearchpress.com/doi/pdf/10.1139/z91-348 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 69, issue 9, page 2470-2479 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1991 crcansciencepubl https://doi.org/10.1139/z91-348 2024-03-08T00:37:43Z Food intake, mass, fat, locomotor activity, and thyroid hormones were monitored in five captive harbour seals (Phoca vitulina) over an 18-month period. Food intake ranged from anorexia to 11% body weight, with changes in body mass reaching 59% in the males. Food intake was negatively related to changes in mass and blubber except during a 6-week period in the fall when the three variables were positively correlated. From the end of November until June, when food intake decreased progressively, mass and fat increased, but not in what was otherwise direct association. Changes in fat were more consistently negatively related to water temperature than were changes in mass. When the male seals were losing weight despite rising food consumption, free thyroxine (T 4 ) levels were positively correlated with food intake and water temperature but negatively correlated with mass and fat changes; the reverse relationships held for ratios of tri-iodothyronine (T 3 ) to free T 4 . Over the winter months, when mass and blubber were augmenting despite lowered food intake, free T 4 levels were significantly lower, whereas T 3 and its ratio to both free and total T 4 were reduced when food intake and mass accumulation were directly related. In the female seal, these hormones were not clearly associated with any of the variables measured. Locomotor activity was positively related to food intake but not in any clear way to levels of thyroid hormones. These results are discussed in the context of the metabolic defense of fat levels for insulation in cooling water. Article in Journal/Newspaper Phoca vitulina Canadian Science Publishing Canadian Journal of Zoology 69 9 2470 2479 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Renouf, Deane Noseworthy, Elizabeth Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Food intake, mass, fat, locomotor activity, and thyroid hormones were monitored in five captive harbour seals (Phoca vitulina) over an 18-month period. Food intake ranged from anorexia to 11% body weight, with changes in body mass reaching 59% in the males. Food intake was negatively related to changes in mass and blubber except during a 6-week period in the fall when the three variables were positively correlated. From the end of November until June, when food intake decreased progressively, mass and fat increased, but not in what was otherwise direct association. Changes in fat were more consistently negatively related to water temperature than were changes in mass. When the male seals were losing weight despite rising food consumption, free thyroxine (T 4 ) levels were positively correlated with food intake and water temperature but negatively correlated with mass and fat changes; the reverse relationships held for ratios of tri-iodothyronine (T 3 ) to free T 4 . Over the winter months, when mass and blubber were augmenting despite lowered food intake, free T 4 levels were significantly lower, whereas T 3 and its ratio to both free and total T 4 were reduced when food intake and mass accumulation were directly related. In the female seal, these hormones were not clearly associated with any of the variables measured. Locomotor activity was positively related to food intake but not in any clear way to levels of thyroid hormones. These results are discussed in the context of the metabolic defense of fat levels for insulation in cooling water. |
format |
Article in Journal/Newspaper |
author |
Renouf, Deane Noseworthy, Elizabeth |
author_facet |
Renouf, Deane Noseworthy, Elizabeth |
author_sort |
Renouf, Deane |
title |
Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
title_short |
Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
title_full |
Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
title_fullStr |
Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
title_full_unstemmed |
Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( Phoca vitulina ) |
title_sort |
changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals ( phoca vitulina ) |
publisher |
Canadian Science Publishing |
publishDate |
1991 |
url |
http://dx.doi.org/10.1139/z91-348 http://www.nrcresearchpress.com/doi/pdf/10.1139/z91-348 |
genre |
Phoca vitulina |
genre_facet |
Phoca vitulina |
op_source |
Canadian Journal of Zoology volume 69, issue 9, page 2470-2479 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z91-348 |
container_title |
Canadian Journal of Zoology |
container_volume |
69 |
container_issue |
9 |
container_start_page |
2470 |
op_container_end_page |
2479 |
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1795672607182290944 |