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Red blood cell function and haematology in two tropical freshwater fishes from Australia

Wells, R. M. G., Baldwin, J., Seymour, R. S., Christian, Keith A. and Brittain, T. (2005). Red blood cell function and haematology in two tropical freshwater fishes from Australia. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology,141(1):87-93.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 14 times in Scopus Article | Citations

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IRMA ID 80801157xPUB29
Title Red blood cell function and haematology in two tropical freshwater fishes from Australia
Author Wells, R. M. G.
Baldwin, J.
Seymour, R. S.
Christian, Keith A.
Brittain, T.
Journal Name Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology
Publication Date 2005
Volume Number 141
Issue Number 1
ISSN 1531-4332   (check CDU catalogue  open catalogue search in new window)
Scopus ID 2-s2.0-20444400158
Start Page 87
End Page 93
Total Pages 7
Place of Publication US
Publisher Elsevier
Field of Research 0606 - Physiology
0608 - Zoology
1116 - Medical Physiology
HERDC Category C1 - Journal Article (DEST)
Abstract Salmon catfish and tarpon occur in habitats that periodically become deficient in oxygen resulting in high mortalities of other fish species. The water-breathing catfish, Arius leptaspis, and the facultative air-breathing tarpon, Megalops cyprinoides, both have high haemoglobin and haematocrit, and the oxygen carrying capacity in the air-breather is exceptionally high (15.6 +/- 1.2 vol%). Iso-pH oxygen equilibria of the red blood cells at 25 degrees C revealed high affinity (P-50 = 9 mmHg, pH 7.4) and co-operativity (n(50) > 2.2, pH 7.4) in the catfish, and contrasted with low affinity (P-50 = 32 mmHg, pH 7.4) and co-operativity (n(50) approximate to 1) in the air-breathing tarpon. Oxygen binding was further distinguished by relative pH insensitivity (Bohr factor, circle divide = Delta log P-50/Delta log pH = -0.22) in the catfish, compared with a significant Bohr effect in the tarpon (circle divide = -0.96). The potential for modulation of haemoglobin-oxygen affinity was indicated by a high ratio of GTP to ATP in the erythrocytes of the catfish, whereas regulation in the tarpon appeared due to ATP alone. Differences in blood respiratory functions between the two species are likely to reflect reduced opportunity for activity under extreme hypoxia in the catfish.
Keywords fish
hypoxia
erythrocyte
oxygen transport
air-breathing
catfish
tarpon
catfish hoplosternum-littorale
hemoglobin-function
aquatic hypoxia
molecular adaptations
oxygen equilibria
armored catfish
arapaima-gigas
air
affinity
evolution
DOI http://dx.doi.org/10.1016/j.cbpb.2005.04.005   (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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