How is oxygen uptake conducted in the green sea turtle?

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It is noted that, the "respiratory properties of sea turtle blood are particularly well suited to lung-tissue transport during routine brethhold periods. Substantial changes in blood gas and pH levels are endured" (Lutz, 1985). As opposed to when the lung is the primary oxygen store, "when blood is a major oxygen store, is loaded on to the blood during breathing periods and unloaded to the tissues during the dives" (Lutz, 1985). Yet, when the lung is the major oxygen store the blood must be efficient in its uptake of oxygen from the lungs down to decreased oxygen levels and transport the oxygen to the tissue. Moreover, "oxygen uptake by the blood is therefore not hampered by a fall in oxygen affinity as lung oxygen is depleted" (Lutz, 1985).

 

 

How does the green sea turtle hemoglobin relate to oxygen consumption?

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Oxygen uptake by blood in green sea turtles is performed by hemoglobins. "Sea turtle hemoglobins are unusual, having an oxygen binding site that remains strained under all physiological conditions" (Friedman, 1985). Hemoglobin plays an integral role in oxygen delivery. It seems that sea turtle hemoglobin is well adapted for deep diving. "Sea turtle hemoglobins appear to be better adapted for release of oxygen to tissues than for uptake of oxygen by the blood" (Friedman, 1985). Furthermore, hemoglobins are able to store and transport oxygen. From this, we can see that the circulatory system is congruous with oxygen storage in "maintaining high levels of oxygen saturation in both arterial and venous bloods" (Friedman, 1985). Since green sea turtles are known for their prolonged submergence, it is logical to observe hematological adjustments.