A comparative study of blood oxygen binding and carrying capacities of turbot Scophthalmus maximus and sea bass Dicentrarchus labrax, two fish species differing in their demand for oxygen, was carried out under three levels of chronic hypoxia (Po2 = 93, 65 and 40 mmHg) for 40 days. Blood O2 affinity in normoxia was moderately high in both species (P50 was c. 12–13 mmHg at pH 7·7). The Bohr factor was significantly lower in turbot (−0·52) than in sea bass (−0·85). In both species, blood O2 affinity was not significantly affected by oxygen depletion whatever its level and duration. In turbot, however, P50 appeared to slightly decrease at the two more severe levels of hypoxia. In both species, blood O2 carrying capacity was not affected by hypoxia and remained twice as high in sea bass than in turbot.
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O2 binding and carrying capacities;
Document Type: Regular Paper
Laboratoire de Biologie et Physiologie Cellulaires, UFR Sciences et Techniques, Université de Bretagne Occidentale, 6 Avenue Le Gorgeu, BP 809, 29285 Brest CEDEX, France and
Laboratoire Arago, Observatoire Océanologique, 66651 Banyuls-sur-mer, France
Publication date: 2003-04-01