Respiratory exchange and transport of oxygen inNautilus pompilius

✍ Scribed by Johansen, K. ;Redmond, J. R. ;Bourne, G. B.

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 737 KB
• Volume: 205
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402050105

✦ Synopsis

Respiratory exchange of oxygen and the role of the hemocyanin-containing blood in gas transport have been studied in the cephalopod Nautilus pompilius.

Nautilus has a blood 0, capacity of 2.30 * 0.57 ~0 1 % .

The oxygen affinity is high compared to that of other cephalopods, Pb0 being 16.9 mmHg a t pH 7.45 and 18°C. The n-value (Hill coefficient) is 2.7 under those conditions. The Bohr factor, 0, is low (i.e. -0.20). The temperature sensitivity, expressed by AH, = -9.8 Kcal. MolHCY-'.

Average values for circulating blood Po2 are 99.2 (* 31.7 mmHg SD) for arterial and 20.4 (* 12.9 mmHg) for venous blood. Arterial blood is fully 0, saturated while the average venous 0, saturation is about 65%. Direct measurements of ventilation average 296 ml. kg-'. min-' while breathing rates vary between 40-60 min-' a t 18-20°C. Breathing rates and ventilation increase during locomotor activity and exposure to hypoxic water.

The results are compared and analysed with available data for other cephalopods. Nautilus, one species of Octopus and the squid Loligo show ascending transport efficiency for 0, correlated with increasing metabolic rates.