Control and Co-Ordination of Gas Exchange in Water Breathers

摘要: Approximately equal amounts of oxygen and carbon dioxide2 are transferred across the gills fish, but in opposite directions, whereas ammonia1 excretion is only 10 to 30% uptake. This is, course, a reflection metabolic utilization production these compounds by fish. The dioxide/oxygen exchange ratio usually between 0.7 1, ammonia/carbon dioxide around 0.1 0.3. Variations ratios outside levels result from changes body stores and/or ammonia, not oxygen, because too small have significant effect on Body ammonia about three times rate per hour, so can marked, nevertheless short-term ratios. Oxygen ignoring that swim bladder, low would supply requirements fish for few minutes, uptake environment approximately utilization. however, act as an store (as well float, sound guide generating organ), bladder being utilized during hypoxia (see Randall Daxboeck 1984). Assuming contains utilize all present, then could maintain tissue several hours.