Flipper stroke rate and venous oxygen levels in free-ranging California sea lions
| Autor: | Paul J. Ponganis, Philip H. Thorson, Luis A. Hückstädt, Michael S. Tift, Birgitte I. McDonald |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
030110 physiology
0301 basic medicine medicine.medical_specialty Stroke rate Zalophus californianus Physiology Diving chemistry.chemical_element Aquatic Science Oxygen Hypoxemia Hemoglobins 03 medical and health sciences Marine mammal Internal medicine medicine Animals Sea lion Molecular Biology Swimming Ecology Evolution Behavior and Systematics biology Free ranging Muscles Anatomy biology.organism_classification Sea Lions chemistry Insect Science Cardiology Female Animal Science and Zoology Blood Gas Analysis medicine.symptom Flipper human activities |
| Zdroj: | Journal of Experimental Biology. |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.152314 |
| Popis: | The depletion rate of the blood oxygen store, development of hypoxemia and dive capacity are dependent on the distribution and rate of blood oxygen delivery to tissues while diving. Although blood oxygen extraction by working muscle would increase the blood oxygen depletion rate in a swimming animal, there is little information on the relationship between muscle workload and blood oxygen depletion during dives. Therefore, we examined flipper stroke rate, a proxy of muscle workload, and posterior vena cava oxygen profiles in four adult female California sea lions ( Zalophus californianus ) during foraging trips at sea. Flipper stroke rate analysis revealed that sea lions minimized muscle metabolism with a stroke–glide strategy when diving, and exhibited prolonged glides during the descent of deeper dives (>100 m). During the descent phase of these deep dives, 55±21% of descent was spent gliding, with the longest glides lasting over 160 s and covering a vertical distance of 340 m. Animals also consistently glided to the surface from 15 to 25 m depth during these deeper dives. Venous hemoglobin saturation ( S O 2 ) profiles were highly variable throughout dives, with values occasionally increasing during shallow dives. The relationship between S O 2 and flipper stroke rate was weak during deeper dives, while this relationship was stronger during shallow dives. We conclude that (1) the depletion of oxygen in the posterior vena cava in deep-diving sea lions is not dependent on stroke effort, and (2) stroke–glide patterns during dives contribute to a reduction of muscle metabolic rate. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|