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Favilla AB, Horning M, Costa DP. Advances in thermal physiology of diving marine mammals: The dual role of peripheral perfusion. Temperature (Austin) 2021; 9:46-66. [PMID: 35655662 PMCID: PMC9154795 DOI: 10.1080/23328940.2021.1988817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The ability to maintain a high core body temperature is a defining characteristic of all mammals, yet their diverse habitats present disparate thermal challenges that have led to specialized adaptations. Marine mammals inhabit a highly conductive environment. Their thermoregulatory capabilities far exceed our own despite having limited avenues of heat transfer. Additionally, marine mammals must balance their thermoregulatory demands with those associated with diving (i.e. oxygen conservation), both of which rely on cardiovascular adjustments. This review presents the progress and novel efforts in investigating marine mammal thermoregulation, with a particular focus on the role of peripheral perfusion. Early studies in marine mammal thermal physiology were primarily performed in the laboratory and provided foundational knowledge through in vivo experiments and ex vivo measurements. However, the ecological relevance of these findings remains unknown because comparable efforts on free-ranging animals have been limited. We demonstrate the utility of biologgers for studying their thermal adaptations in the context in which they evolved. Our preliminary results from freely diving northern elephant seals (Mirounga angustirostris) reveal blubber’s dynamic nature and the complex interaction between thermoregulation and the dive response due to the dual role of peripheral perfusion. Further exploring the potential use of biologgers for measuring physiological variables relevant to thermal physiology in other marine mammal species will enhance our understanding of the relative importance of morphology, physiology, and behavior for thermoregulation and overall homeostasis.
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Affiliation(s)
- Arina B. Favilla
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States
| | - Markus Horning
- Wildlife Technology Frontiers, Seward, AK, United States
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States
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2
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Ponganis PJ. A Physio-Logging Journey: Heart Rates of the Emperor Penguin and Blue Whale. Front Physiol 2021; 12:721381. [PMID: 34413792 PMCID: PMC8369151 DOI: 10.3389/fphys.2021.721381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/08/2021] [Indexed: 11/23/2022] Open
Abstract
Physio-logging has the potential to explore the processes that underlie the dive behavior and ecology of marine mammals and seabirds, as well as evaluate their adaptability to environmental change and other stressors. Regulation of heart rate lies at the core of the physiological processes that determine dive capacity and performance. The bio-logging of heart rate in unrestrained animals diving at sea was infeasible, even unimaginable in the mid-1970s. To provide a historical perspective, I review my 40-year experience in the development of heart rate physio-loggers and the evolution of a digital electrocardiogram (ECG) recorder that is still in use today. I highlight documentation of the ECG and the interpretation of heart rate profiles in the largest of avian and mammalian divers, the emperor penguin and blue whale.
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Affiliation(s)
- Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States
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3
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Williams CL, Ponganis PJ. Diving physiology of marine mammals and birds: the development of biologging techniques. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200211. [PMID: 34121464 PMCID: PMC8200650 DOI: 10.1098/rstb.2020.0211] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2021] [Indexed: 11/12/2022] Open
Abstract
In the 1940s, Scholander and Irving revealed fundamental physiological responses to forced diving of marine mammals and birds, setting the stage for the study of diving physiology. Since then, diving physiology research has moved from the laboratory to the field. Modern biologging, with the development of microprocessor technology, recorder memory capacity and battery life, has advanced and expanded investigations of the diving physiology of marine mammals and birds. This review describes a brief history of the start of field diving physiology investigations, including the invention of the time depth recorder, and then tracks the use of biologging studies in four key diving physiology topics: heart rate, blood flow, body temperature and oxygen store management. Investigations of diving heart rates in cetaceans and O2 store management in diving emperor penguins are highlighted to emphasize the value of diving physiology biologging research. The review concludes with current challenges, remaining diving physiology questions and what technologies are needed to advance the field. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
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Affiliation(s)
- Cassondra L. Williams
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Paul J. Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
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4
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Watanabe YY, Goldbogen JA. Too big to study? The biologging approach to understanding the behavioural energetics of ocean giants. J Exp Biol 2021; 224:270831. [PMID: 34232316 DOI: 10.1242/jeb.202747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Wild animals are under selective pressure to optimise energy budgets; therefore, quantifying energy expenditure, intake and allocation to specific activities is important if we are to understand how animals survive in their environment. One approach toward estimating energy budgets has involved measuring oxygen consumption rates under controlled conditions and constructing allometric relationships across species. However, studying 'giant' marine vertebrates (e.g. pelagic sharks, whales) in this way is logistically difficult or impossible. An alternative approach involves the use of increasingly sophisticated electronic tags that have allowed recordings of behaviour, internal states and the surrounding environment of marine animals. This Review outlines how we could study the energy expenditure and intake of free-living ocean giants using this 'biologging' technology. There are kinematic, physiological and theoretical approaches for estimating energy expenditure, each of which has merits and limitations. Importantly, tag-derived energy proxies can hardly be validated against oxygen consumption rates for giant species. The proxies are thus qualitative, rather than quantitative, estimates of energy expenditure, and have more limited utilities. Despite this limitation, these proxies allow us to study the energetics of ocean giants in their behavioural context, providing insight into how these animals optimise their energy budgets under natural conditions. We also outline how information on energy intake and foraging behaviour can be gained from tag data. These methods are becoming increasingly important owing to the natural and anthropogenic environmental changes faced by ocean giants that can alter their energy budgets, fitness and, ultimately, population sizes.
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Affiliation(s)
- Yuuki Y Watanabe
- National Institute of Polar Research, Tachikawa, Tokyo 190-8518, Japan.,Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, Tachikawa, Tokyo 190-8518, Japan
| | - Jeremy A Goldbogen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950, USA
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5
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Williams CL, Hindle AG. Field Physiology: Studying Organismal Function in the Natural Environment. Compr Physiol 2021; 11:1979-2015. [PMID: 34190338 DOI: 10.1002/cphy.c200005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Continuous physiological measurements collected in field settings are essential to understand baseline, free-ranging physiology, physiological range and variability, and the physiological responses of organisms to disturbances. This article presents a current summary of the available technologies to continuously measure the direct physiological parameters in the field at high-resolution/instantaneous timescales from freely behaving animals. There is a particular focus on advantages versus disadvantages of available methods as well as emerging technologies "on the horizon" that may have been validated in captive or laboratory-based scenarios but have yet to be applied in the wild. Systems to record physiological variables from free-ranging animals are reviewed, including radio (VHF/UFH) telemetry, acoustic telemetry, and dataloggers. Physiological parameters that have been continuously measured in the field are addressed in seven sections including heart rate and electrocardiography (ECG); electromyography (EMG); electroencephalography (EEG); body temperature; respiratory, blood, and muscle oxygen; gastric pH and motility; and blood pressure and flow. The primary focal sections are heart rate and temperature as these can be, and have been, extensively studied in free-ranging organisms. Predicted aspects of future innovation in physiological monitoring are also discussed. The article concludes with an overview of best practices and points to consider regarding experimental designs, cautions, and effects on animals. © 2021 American Physiological Society. Compr Physiol 11:1979-2015, 2021.
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Affiliation(s)
- Cassondra L Williams
- National Marine Mammal Foundation, San Diego, California, USA.,Department of Ecology and Evolutionary Biology, School of Biological Science, University of California Irvine, Irvine, California, USA
| | - Allyson G Hindle
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
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6
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Fahlman A, Aoki K, Bale G, Brijs J, Chon KH, Drummond CK, Føre M, Manteca X, McDonald BI, McKnight JC, Sakamoto KQ, Suzuki I, Rivero MJ, Ropert-Coudert Y, Wisniewska DM. The New Era of Physio-Logging and Their Grand Challenges. Front Physiol 2021; 12:669158. [PMID: 33859577 PMCID: PMC8042203 DOI: 10.3389/fphys.2021.669158] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 02/26/2021] [Indexed: 12/20/2022] Open
Affiliation(s)
- Andreas Fahlman
- Fundación Oceanográfic de la Comunitat Valenciana, Valencia, Spain
| | - Kagari Aoki
- Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Gemma Bale
- Department of Physics and Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Jeroen Brijs
- Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Manoa, HI, United States
| | - Ki H. Chon
- Biomedical Engineering, University of Connecticut, Storrs, CT, United States
| | - Colin K. Drummond
- Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Martin Føre
- Department of Engineering Cybernetics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Xavier Manteca
- Department of Animal and Food Science, Autonomous University of Barcelona, Barcelona, Spain
| | - Birgitte I. McDonald
- Moss Landing Marine Labs at San Jose State University, Moss Landing, CA, United States
| | - J. Chris McKnight
- Sea Mammal Research Unit, University of St. Andrews, Scotland, United Kingdom
| | - Kentaro Q. Sakamoto
- Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Ippei Suzuki
- Akkeshi Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Akkeshi, Japan
| | | | - Yan Ropert-Coudert
- Centre D'Etudes Biologiques de Chizé, La Rochelle Université, UMR7372, CNRS, France
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7
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Favilla AB, Costa DP. Thermoregulatory Strategies of Diving Air-Breathing Marine Vertebrates: A Review. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.555509] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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8
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Mason MJ, Wenger LMD, Hammer Ø, Blix AS. Structure and function of respiratory turbinates in phocid seals. Polar Biol 2020. [DOI: 10.1007/s00300-019-02618-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
AbstractIn terrestrial mammals, the respiratory turbinate bones within the nasal cavity are employed to conserve heat and water. In order to investigate whether environmental temperature affects respiratory turbinate structure in phocids, we used micro-computed tomography to compare maxilloturbinate bone morphology in polar seals, grey seals and monk seals. The maxilloturbinates of polar seals have much higher surface areas than those of monk seals, the result of the polar seals having more densely packed, complex turbinates within larger nasal cavities. Grey seals were intermediate; a juvenile of this species proved to have more densely packed maxilloturbinates with shorter branch lengths than a conspecific adult. Fractal dimension in the densest part of the maxilloturbinate mass was very close to 2 in all seals, indicating that these convoluted bones evenly fill the available space. The much more elaborate maxilloturbinate systems in polar seals, compared with monk seals, are consistent with a greater need to limit respiratory heat loss.
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Abstract
This Review focuses on the original papers that have made a difference to our thinking and were first in describing an adaptation to diving, and less on those that later repeated the findings with better equipment. It describes some important anatomical peculiarities of phocid seals, as well as their many physiological responses to diving. In so doing, it is argued that the persistent discussions on the relevance and differences between responses seen in forced dives in the laboratory and those during free diving in the wild are futile. In fact, both are two sides of the same coin, aimed at protecting the body against asphyxic insult and extending diving performance.
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Affiliation(s)
- Arnoldus Schytte Blix
- Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, 9037 Tromsø, Norway .,St Catharine's College, Cambridge CB2 1RL, UK
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10
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Tift MS, Hückstädt LA, McDonald BI, Thorson PH, Ponganis PJ. Flipper stroke rate and venous oxygen levels in free-ranging California sea lions. ACTA ACUST UNITED AC 2017; 220:1533-1540. [PMID: 28167807 DOI: 10.1242/jeb.152314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/01/2017] [Indexed: 11/20/2022]
Abstract
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 (SO2 ) profiles were highly variable throughout dives, with values occasionally increasing during shallow dives. The relationship between SO2 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.
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Affiliation(s)
- Michael S Tift
- Scripps Institution of Oceanography, University of California San Diego, Center for Marine Biodiversity and Biomedicine, 8655 Kennel Way, La Jolla, CA 92037, USA
| | - Luis A Hückstädt
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Long Marine Lab, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Birgitte I McDonald
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA
| | - Philip H Thorson
- Institute of Marine Sciences, University of California Santa Cruz, Long Marine Laboratory, 100 Shaffer Road, CA 95060, USA
| | - Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, Center for Marine Biodiversity and Biomedicine, 8655 Kennel Way, La Jolla, CA 92037, USA
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11
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Diving physiology of seabirds and marine mammals: Relevance, challenges and some solutions for field studies. Comp Biochem Physiol A Mol Integr Physiol 2016; 202:38-52. [PMID: 27421239 DOI: 10.1016/j.cbpa.2016.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 07/06/2016] [Accepted: 07/06/2016] [Indexed: 11/20/2022]
Abstract
To fully understand how diving seabirds and marine mammals balance the potentially conflicting demands of holding their breath while living their lives underwater (and maintaining physiological homeostasis during exercise, feeding, growth, and reproduction), physiological studies must be conducted with animals in their natural environments. The purpose of this article is to review the importance of making physiological measurements on diving animals in field settings, while acknowledging the challenges and highlighting some solutions. The most extreme divers are great candidates for study, especially in a comparative and mechanistic context. However, physiological data are also required of a wide range of species for problems relating to other disciplines, in particular ecology and conservation biology. Physiological data help with understanding and predicting the outcomes of environmental change, and the direct impacts of anthropogenic activities. Methodological approaches that have facilitated the development of field-based diving physiology include the isolated diving hole protocol and the translocation paradigm, and while there are many techniques for remote observation, animal-borne biotelemetry, or "biologging", has been critical. We discuss issues related to the attachment of instruments, the retrieval of data and sensing of physiological variables, while also considering negative impacts of tagging. This is illustrated with examples from a variety of species, and an in-depth look at one of the best studied and most extreme divers, the emperor penguin (Aptenodytes forsteri). With a variety of approaches and high demand for data on the physiology of diving seabirds and marine mammals, the future of field studies is bright.
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12
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Chicco AJ, Le CH, Schlater AE, Nguyen AD, Kaye SD, Beals JW, Scalzo RL, Bell C, Gnaiger E, Costa DP, Crocker DE, Kanatous SB. High fatty acid oxidation capacity and phosphorylation control despite elevated leak and reduced respiratory capacity in northern elephant seal muscle mitochondria. J Exp Biol 2014; 217:2947-55. [DOI: 10.1242/jeb.105916] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abstract
Northern elephant seals (Mirounga angustirostris) are extreme, hypoxia-adapted endotherms that rely largely on aerobic metabolism during extended breath-hold dives in near freezing water temperatures. While many aspects of their physiology have been characterized to account for these remarkable feats, the contribution of adaptations in the aerobic powerhouses of muscle cells, the mitochondria, are unknown. In the present study, the ontogeny and comparative physiology of elephant seal muscle mitochondrial respiratory function was investigated under a variety of substrate conditions and respiratory states. Intact mitochondrial networks were studied by high-resolution respirometry in saponin-permeabilized fiber bundles obtained from primary swimming muscles of pup, juvenile, and adult seals, and compared to fibers from adult human vastus laterais. Results indicate that seal muscle maintains a high capacity for fatty acid oxidation despite a progressive decrease in total respiratory capacity as animals mature from pups to adults. This is explained by a progressive increase in phosphorylation control and fatty acid utilization over pyruvate in adult seals compared to humans and seal pups. Interestingly, despite higher indices of oxidative phosphorylation efficiency, juvenile and adult seals also exhibit a ~50% greater capacity for respiratory leak compared to humans and pups. The ontogeny of this phenotype suggests it is an adaptation of muscle to the prolonged breath-hold exercise and highly variable ambient temperatures experienced by mature elephant seals. These studies highlight the remarkable plasticity of mammalian mitochondria to meet the demands for both efficient ATP production and endothermy in a cold, oxygen-limited environment.
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13
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Castellini M. Life under water: physiological adaptations to diving and living at sea. Compr Physiol 2013; 2:1889-919. [PMID: 23723028 DOI: 10.1002/cphy.c110013] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review covers the field of diving physiology by following a chronological approach and focusing heavily on marine mammals. Because the study of modern diving physiology can be traced almost entirely to the work of Laurence Irving in the 1930s, this particular field of physiology is different than most in that it did not derive from multiple laboratories working at many locations or on different aspects of a similar problem. Because most of the physiology principles still used today were first formulated by Irving, it is important to the study of this field that the sequence of thought is examined as a progression of theory. The review covers the field in roughly decadal blocks and traces ideas as they were first suggested, tested, modified and in some cases, abandoned. Because diving physiology has also been extremely dependent on new technologies used in the development of diving recorders, a chronological approach fits well with advances in electronics and mechanical innovation. There are many species that dive underwater as part of their natural behavior, but it is mainly the marine mammals (seals, sea lions, and whales) that demonstrate both long duration and dives to great depth. There have been many studies on other diving species including birds, snakes, small aquatic mammals, and humans. This work examines these other diving species as appropriate and a listing of reviews and relevant literature on these groups is included at the end.
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Affiliation(s)
- Michael Castellini
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska.
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14
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Field CL, Tablin F. Response of Northern Elephant Seal platelets to pressure and temperature changes: A comparison with human platelets. Comp Biochem Physiol A Mol Integr Physiol 2012; 162:289-95. [DOI: 10.1016/j.cbpa.2012.01.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 10/28/2022]
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15
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Soegaard LB, Hansen MN, van Elk C, Brahm J, Jensen FB. Respiratory properties of blood in the harbor porpoise, Phocoena phocoena. J Exp Biol 2012; 215:1938-43. [DOI: 10.1242/jeb.069872] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Harbor porpoises are active divers that exchange O2 and CO2 with the environment during a fast single breath upon surfacing. We investigated blood O2-transporting properties, buffer characteristics, Cl– transport via the erythrocyte anion exchanger (AE1), circulating nitric oxide metabolites and hemoglobin nitrite reduction in harbor porpoises with the aim to evaluate traits that are adaptive for diving behavior. Blood O2 affinity was higher in harbor porpoises than in similar sized terrestrial mammals, as supported by our parallel recordings of O2 equilibria in sheep and pig blood. Further, O2 affinity tended to increase with increasing body mass. A high O2 affinity favors O2 extraction from the lungs, but a normal Bohr effect (ΔlogP50/ΔpH=–0.46) gradually lowers O2 affinity during dives (where CO2 accumulates) to assist O2 off-loading to perfused tissues. The true plasma non-bicarbonate buffer value was moderately higher than in terrestrial mammals and increased upon deoxygenation. Plasma bicarbonate was also relatively high, contributing to increase the overall buffer capacity. The apparent Cl– permeability of harbor porpoise erythrocytes was similar to the human value at 37°C, showing absence of a comparative increase in the velocity of erythrocyte HCO –3/Cl– exchange to aid CO2 excretion. The Q10 for AE1-mediated Cl– transport in harbor porpoises was lower than in humans and seemed to match the Q10 for metabolism (Q10≈2). Plasma nitrite, plasma nitrate and hemoglobin-mediated nitrite reduction were elevated compared with mammalian standards, suggesting that increased nitric oxide bioavailability and nitrite-derived nitric oxide could play important roles in diving physiology.
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Affiliation(s)
- Lisette B. Soegaard
- Institute of Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
- Fjord and Belt, DK-5300 Kerteminde, Denmark
| | - Marie N. Hansen
- Institute of Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | | | - Jesper Brahm
- Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark
| | - Frank B. Jensen
- Institute of Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
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16
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Anholm JD, Foster GP. The 17th International Hypoxia Symposium: Hypoxia and Cancer, February 15-20, 2011. High Alt Med Biol 2012; 12:285-9. [PMID: 21962073 DOI: 10.1089/ham.2011.1032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- James D Anholm
- Pulmonary and Critical Care Section, Veterans Administration Loma Linda Healthcare System, Loma Linda, California 92357, USA.
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17
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Ponganis PJ, Meir JU, Williams CL. In pursuit of Irving and Scholander: a review of oxygen store management in seals and penguins. J Exp Biol 2011; 214:3325-39. [DOI: 10.1242/jeb.031252] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
Since the introduction of the aerobic dive limit (ADL) 30 years ago, the concept that most dives of marine mammals and sea birds are aerobic in nature has dominated the interpretation of their diving behavior and foraging ecology. Although there have been many measurements of body oxygen stores, there have been few investigations of the actual depletion of those stores during dives. Yet, it is the pattern, rate and magnitude of depletion of O2 stores that underlie the ADL. Therefore, in order to assess strategies of O2 store management, we review (a) the magnitude of O2 stores, (b) past studies of O2 store depletion and (c) our recent investigations of O2 store utilization during sleep apnea and dives of elephant seals (Mirounga angustirostris) and during dives of emperor penguins (Aptenodytes forsteri). We conclude with the implications of these findings for (a) the physiological responses underlying O2 store utilization, (b) the physiological basis of the ADL and (c) the value of extreme hypoxemic tolerance and the significance of the avoidance of re-perfusion injury in these animals.
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Affiliation(s)
- Paul J. Ponganis
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| | - Jessica U. Meir
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Cassondra L. Williams
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA, 92697, USA
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