Physiological responses to prolonged aquatic hypoxia in the Queensland lungfish Neoceratodus forsteri

摘要: The effects of moderate and severe hypoxia on air breathing frequency respiratory properties the blood Queensland (Australian) lungfish Neoceratodus forsteri were measured in fish exposed to these conditions for 14-22 days at 20 degrees C. Haemoglobin oxygen affinity increased after exposure (PwO2 = 60 mmHg), but did not increase further =40 mmHg). P50 whole (20 C, PCO2 =16.0 mmHg) fell from 22.0 +/- 1.5 mmHg normoxic 19.0 1.0 hypoxic conditions. Under both hypoxia, haematocrit, haemoglobin, lactate, erythrocyte phosphate concentrations differ values. observed haemoglobin response aquatic is typical compensatory responses seen obligate water breathers, smaller. This suggests that capacity respond by removes necessity left-shifting equilibrium curve.