Condition and mass impact oxygen stores and dive duration in adult female northern elephant seals
| Autor: | Birgitte I. McDonald, Samantha E. Simmons, Patrick W. Robinson, Daniel E. Crocker, Jason L. Hassrick, Daniel P. Costa, Nicole M. Teutschel |
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| Rok vydání: | 2010 |
| Předmět: |
Blood Volume
Time Factors Adult female Myoglobin Seals Earless Physiology Ecology Diving Body Weight Age Factors Aquatic Science Biology biology.organism_classification Oxygen Pregnancy Duration (music) Insect Science Elephant seal Animals Female Animal Science and Zoology human activities Molecular Biology Ecology Evolution Behavior and Systematics Demography |
| Zdroj: | Journal of Experimental Biology. 213:585-592 |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.037168 |
| Popis: | SUMMARYThe range of foraging behaviors available to deep-diving, air-breathing marine vertebrates is constrained by their physiological capacity to breath-hold dive. We measured body oxygen stores (blood volume and muscle myoglobin) and diving behavior in adult female northern elephant seals, Mirounga angustirostris, to investigate age-related effects on diving performance. Blood volume averaged 74.4±17.0 liters in female elephant seals or 20.2±2.0% of body mass. Plasma volume averaged 32.2±7.8 liters or 8.7±0.7% of body mass. Absolute plasma volume and blood volume increased independently with mass and age. Hematocrit decreased weakly with mass but did not vary with age. Muscle myoglobin concentration, while higher than previously reported (7.4±0.7 g%), did not vary with mass or age. Pregnancy status did not influence blood volume. Mean dive duration, a proxy for physiological demand, increased as a function of how long seals had been at sea, followed by mass and hematocrit. Strong effects of female body mass (range, 218-600 kg) on dive duration, which were independent of oxygen stores, suggest that larger females had lower diving metabolic rates. A tendency for dives to exceed calculated aerobic limits occurred more frequently later in the at-sea migration. Our data suggest that individual physiological state variables and condition interact to determine breath-hold ability and that both should be considered in life-history studies of foraging behavior. |
| Databáze: | OpenAIRE |
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