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Changes in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon

Clark, T. D., Seymour, R. S., Christian, Keith A., Wells, R. M. G., Baldwin, J. and Farrell, A. P. (2007). Changes in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology,148(3):562-571.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 9 times in Scopus Article | Citations

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IRMA ID 80801157xPUB35
Title Changes in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon
Author Clark, T. D.
Seymour, R. S.
Christian, Keith A.
Wells, R. M. G.
Baldwin, J.
Farrell, A. P.
Journal Name Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology
Publication Date 2007
Volume Number 148
Issue Number 3
ISSN 1531-4332   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-34748859191
Start Page 562
End Page 571
Total Pages 10
Place of Publication US
Publisher Elsevier
Field of Research 0606 - Physiology
0608 - Zoology
1116 - Medical Physiology
HERDC Category C1 - Journal Article (DEST)
Abstract Pacific tarpon (Megalops cyprinoides) use a modified gas bladder as an air-breathing organ (ABO). We examined changes in cardiac output (V-b) associated with increases in air-breathing that accompany exercise and aquatic hypoxia. Juvenile (0.49 kg) and adult (1.21 kg) tarpon were allowed to recover in a swim flume at 27 'C after being instrumented with a Doppler flow probe around the ventral aorta to monitor band with a fibre-optic o en sensor in the ABO to monitor air-breathing frequency. Under normoxic conditions and in both juveniles and adults, routine air-breathing frequency was 0.03 breaths min(-1) and V-b was about 15 mL min(-1) kg(-1). Normoxic exercise (swimming at about 1.1 body lengths s(-1)) increased air-breathing frequency by 8-fold in both groups (reaching 0.23 breaths min(-1)) and increased Rb by 3-fold for juveniles and 2-fold for adults. Hypoxic exposure (2 kPa O-2) at rest increased air-breathing frequency 19-fold (to around 0.53 breaths min(-1)) in both groups, and while V-b again increased 3-fold in resting juvenile fish, V-b was unchanged in resting adult fish. Exercise in hypoxia increased air-breathing frequency 35-fold (to 0.95 breaths min(-1)) in comparison with resting normoxic fish. While juvenile fish increased V-b nearly 2-fold with exercise in hypoxia, adult fish maintained the same V-b irrespective of exercise state and became agitated in comparison. These results imply that air-breathing during exercise and hypoxia can benefit oxygen delivery, but to differing degrees in juvenile and adult tarpon. We discuss this difference in the context of myocardial oxygen supply.
Keywords air-breathing fish
aerial respiration
cardiac output
exercise
compact myocardium
heart rate
megalops cyprinoides
trout oncorhynchus
coronary blood flow
fish amia calva
rainbow trout
synbranchus marmoratus
megalops cyprinoides
cardiovascular responses
ectothermic vertebrates
oxygen transport
gas exchange
DOI http://dx.doi.org/10.1016/j.cbpa.2007.07.007   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
 
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