Blood Function in the Hydrothermal Vent Vestimentiferan Tube Worm

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Science  17 Jul 1981:
Vol. 213, Issue 4505, pp. 342-344
DOI: 10.1126/science.213.4505.342


Extracellular hemoglobin in the whole blood of Riftia pachyptila has a high oxygen affinity (P50 = 1.8 millimeters of mercury at 3°C), a moderate decrease in oxygen affinity at higher temperatures (P50 = 2.7 millimeters of mercury at 14°C), a small effect of carbon dioxide on oxygen affinity (Δ log P50/Δ pH =–0.12), and a high oxygen carrying capacity (up to 11 milliliters of oxygen per 100 milliliters of blood). These characteristics are compatible with the high oxygen demand of chemoautotrophic metabolism in the variable vent environment.