Seasonal differences in physiology of captive steller sea lions (eumetopias jubatus) in response to short-term low energy intake ...
Steller sea lions (Eumetopias jubatus) were fed restricted iso-caloric amounts of Pacific herring (Clupea pallasi) or walleye pollock (Theragra chalcogramma) for 8-9 days, four times a year. At these levels, the sea lions lost an average of 10.1% of their initial body mass while on both experimental...
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| Format: | Text |
| Language: | English |
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University of British Columbia
2009
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| Online Access: | https://dx.doi.org/10.14288/1.0074878 https://doi.library.ubc.ca/10.14288/1.0074878 |
| Summary: | Steller sea lions (Eumetopias jubatus) were fed restricted iso-caloric amounts of Pacific herring (Clupea pallasi) or walleye pollock (Theragra chalcogramma) for 8-9 days, four times a year. At these levels, the sea lions lost an average of 10.1% of their initial body mass while on both experimental diets for up to nine days, but at a significantly higher rate in winter and at a lower rate in summer. Decreases in body fat mass and standard metabolic rates during the trials were similar throughout the seasons and for both diets. Metabolic depression was not always observed during the trials despite the constant loss of body mass. Changes in Cortisol, triiodothyronine and blood urea nitrogen (BUN) were seasonally dependent. Over the course of the trials, serum levels of Cortisol and BUN increased and total triiodothyronine decreased the most in winter. Serum Cortisol levels correlated negatively with both body mass and body condition suggesting that Cortisol may play an important role in body fat regulation in ... |
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