| Popis: |
The erythrocytes of the amphibious mudfish, Neochanna burrowsius, contained 6.8 μmol ATP/ml red cells and 4.4 μmol GTP Trinucleotide concentrations were not significantly changed in fish acclimated for 3 wk in moist air. The oxygen affinity, defined by the half-saturation oxygen tension (P50), of whole blood at 12 C was 11 mm Hg at pH 7.8 and 18 mm Hg at pH 7.4 in water-breathing mudfish. No appreciable Root shift was observed. O₂ affinity decreased in air-acclimated fish at low pH (25 mm Hg at pH 7.4). This corresponded to an increase in the Bohr effect (Δlog P50/ΔpH) from -0.6 in water to - 0.8 in air. The similarity between oxygen equilibrium curves and other hematological parameters from the two groups of fish reflects the common mode of gas exchange, with more than 50% of oxygen taken up by skin in either air or water. |
