Oxygen and Carbon Dioxide Transport by Blood Containing Haemocyanin 



of some interest in relation to the increase of metabolic rate at rising 

 temperatures in poikilothermic animals. In the second place there is 

 an enormous Bohr effect {Figure 3). 



100 



10 20 JO 40 SO 60 70 80 90 100 I/O 120 I JO 



Po 2 



Figure 3. Oxygen dissociation 

 curves of the blood of the lobster. 



Figure 4. Oxygen dissociation 



curves of the blood of the 



edible crab. 



p o 2 



The displacement of the dissociation curve of the edible crab {Cancer 

 pagurus L) by carbon dioxide on the contrary, is comparatively small 

 {Figure 4). 



The crab is a very sluggish animal feeding on mussels. One is 

 particularly struck by the extraordinarily slow movements of the 

 powerful claw muscles. The lobster spends much of its life in hiding 

 places but will, when capturing a prey or trying to escape some enemy, 

 execute a series of vigorous quick movements, during which the oxygen 

 consumption must rise considerably, and this call for extra oxygen 





H— 20 



305 



