The respiration of the porpoise, tursiops truncatus

Irving, Laurence; Scholander, P. F.; Grinnell, S. W.

doi:10.1002/jcp.1030170203

Cited by 146 publications

(78 citation statements)

References 10 publications

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“…Such a variable dive response raises questions about the management of blood gases during submergence. Although there is a premium to conserve oxygen through bradycardia and an associated redistribution of blood flow (Scholander, 1940;Irving et al, 1941;Harrison and Tomlinson, 1960;Elsner, 1965;Elsner et al, 1966), heart rate varies with the intensity of underwater behaviors (Figs4, 5), as does peripheral blood flow, as evident from changes in skin temperature and heat flow from the extremities of diving dolphins Noren et al, 1999). Rather than a hindrance to diving, alterations in blood flow (as facilitated by alterations in heart rate) throughout submergence theoretically facilitate more effective unloading of endogenous oxygen stores by enabling the parallel depletion of the blood and muscle oxygen reserves .…”

Section: Discussionmentioning

confidence: 99%

“…In their original experiments with forcibly submerged animals, Scholander and colleagues (Scholander, 1940;Irving et al, 1941;Scholander et al, 1942) described the suite of physiological adjustments that occur during breath-hold across terrestrial and aquatic animals alike. Originally termed the 'diving reflex', the adjustments included a characteristic, pronounced slowing of the heart (bradycardia) and peripheral vasoconstriction that accompanied the cessation of breathing upon submergence.…”

Section: Introductionmentioning

confidence: 99%

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The dive response redefined: underwater behavior influences cardiac variability in freely diving dolphins

Noren

Kendall

Cuccurullo³

et al. 2012

Journal of Experimental Biology

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SUMMARYA hallmark of the dive response, bradycardia, promotes the conservation of onboard oxygen stores and enables marine mammals to submerge for prolonged periods. A paradox exists when marine mammals are foraging underwater because activity should promote an elevation in heart rate (f H ) to support increased metabolic demands. To assess the effect of the interaction between the diving response and underwater activity on f H , we integrated interbeat f H with behavioral observations of adult bottlenose dolphins diving and swimming along the coast of the Bahamas. As expected for the dive response, f H while resting during submergence (40±6beatsmin , and occurred during post-dive surface intervals. During submergence, the level of bradycardia was modified by activity. Behaviors such as simple head bobbing at depth increased f H by 40% from submerged resting levels. Higher heart rates were observed for horizontal swimming at depth. Indeed, the dolphins operated at 37-58% of their f H,max while active at depth and approached 57-79% of their f H,max during anticipatory tachycardia as the animals glided to the surface. f H was significantly correlated with stroke frequency (range0-2.5strokess -1 , r0.88, N25 dives) and calculated swim speed (range0-5.4ms -1 , r0.88, N25 dives). We find that rather than a static reflex, the dive response is modulated by behavior and exercise in a predictable manner.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The dive response redefined: underwater behavior influences cardiac variability in freely diving dolphins

Noren

Kendall

Cuccurullo³

et al. 2012

Journal of Experimental Biology

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“…The activity of these respiratory enzymes in dolphin tissues was lower than that of the corresponding rat tissues. Since the oxygen consumption of dolphins is somewhat higher than that for man per unit weight (8), it is unlikely that the lower respiratory enzyme activity in dolphin tissues as compared with rats is due to adaptation for possible diminished oxygen supply, but it is probably rather a reflection of a slower rate of metabolism in dolphins as compared with rats. A comparison of the enzyme activities obtained in dolphin tissues with those of the tissues of large terrestial mammals would be of interest when data on the latter animals obtained by the same methods become available.…”

Section: Discussionmentioning

confidence: 99%

“…Irving, Scholander, and Grinnell (8) studied the respiration of dolphins during rest and diving and found that the resting oxygen consumption was less than that for seals but somewhat greater than for man per unit of weight. They reported that the lactic acid content of the muscle tissue of dolphins did not change significantly during the dive and that blood lactate values were not altered during or after diving, in contrast to the results obtained on rats and ducks (9) and on seals (8) in which lactic acid increased in the muscle during diving and in the blood during recovery.…”

mentioning

confidence: 84%

Studies on the Intermediary Carbohydrate Metabolism of Aquatic Animals

DuBois

Geiling

McBride

et al. 1948

Journal of General Physiology

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The differences and similarities between aquatic and terresfial mammals have been the subjects of several investigations (1-3). Studies of the gross and hlstologic anatomy of the lungs of several marine mammals have disclosed some structural modifications peculiar to these species (4, 5). The problems of adaptation of physical structure to an aquatic environment have been discussed by Kellogg (6) and the physiology of respiration of diving animals has been reviewed by Irving (7).The mechanisms for controlling the oxygen supply to the tissues and the ability of many marine mammals to undergo long periods of submergence have been of great interest. Irving, Scholander, and Grinnell (8) studied the respiration of dolphins during rest and diving and found that the resting oxygen consumption was less than that for seals but somewhat greater than for man per unit of weight. They reported that the lactic acid content of the muscle tissue of dolphins did not change significantly during the dive and that blood lactate values were not altered during or after diving, in contrast to the results obtained on rats and ducks (9) and on seals (8) in which lactic acid increased in the muscle during diving and in the blood during recovery.With some information on the over-all physiology of the dolphin at hand, it was of interest to study the intermediary cellular metabolism, since fundamental differences in the metabolism of aquatic and terrestial mammals must certainly reflect variations in enzymatic processes. Except for the findings of Manery, Welch, and Irving (10) that excised seal skeletal muscle can glycolyze to the same extent as rabbit muscle, data on the concentrations of the intermediates of glycolysis and on the respiratory and glycolytic enzymes in the

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“…Some species can hold their breath for as long as 2 h during deep dives, resulting in a greater magnitude and duration of exposure to inhaled toxic chemicals (Irving et al 1941, Ridgway et al 1969, Green 1972, Ridgway 1972, Schorr et al 2014. They also lack turbinates that filter air en route to the lungs, and they have an extensive blood supply in their lungs, facilitating absorption of toxicants into the blood.…”

Section: Inhalationmentioning

confidence: 99%