. The comparative physiology of respiratory mechanisms. Respiration. FUNCTIONS OF BLOOD 105 days at lower tensions. In their natural habitats the Chiro- nomid larvae can stand much lower oxygen tensions and per- haps even complete oxygen lack (Juday, 1908), probably by changing over partially or completely to anaerobic me- tabolism (Harnisch, 1936). Willmer (1934) describes the very peculiar situation of fishes in tropical swamps in British Guiana. The oxygen is so low (and often practically absent) that the fishes have had to develop accessory organs for breath- ing air. At the same time they
. The comparative physiology of respiratory mechanisms. Respiration. FUNCTIONS OF BLOOD 105 days at lower tensions. In their natural habitats the Chiro- nomid larvae can stand much lower oxygen tensions and per- haps even complete oxygen lack (Juday, 1908), probably by changing over partially or completely to anaerobic me- tabolism (Harnisch, 1936). Willmer (1934) describes the very peculiar situation of fishes in tropical swamps in British Guiana. The oxygen is so low (and often practically absent) that the fishes have had to develop accessory organs for breath- ing air. At the same time they are exposed to water with a C02 tension which is sometimes very high. In these circumstances their dissociation curves are not very steep, but the C02 effect is very much reduced (Fig. 60). In one fish, the yarrow (Erythrinus), Willmer studied the complex relations between the gas content of the water and. 20 30 40 50 60 70 80 90 100 Oxygen pressure in mm. Hg Fig. 60. Oxygen dissociation curves for blood of electric eel at C02 tensions from 0 to 25 mm. (Willmer.) u 45 45 N 40 40 n u 35 35 N o 30 30 •" u 25 25 c 0 20 20 O 1 ) —> !5 15 c C3 in 10 10 3 in \n 5 5 a, t ? mm. cc. o Hg per u litre CO, too high|Aeidaemia(?)) Gill operculum actively closed . u . :• kept vntu". Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Krogh, August, 1874-1949. Philadelphia, University of Pennsylvania press
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Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectrespiration
