. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. OXYGEN CONSUMPTION IN GOLDFISH 71 oxygen uptake is plotted gainst oxygen tension. These curves were derived by tak- ing tangents from the appropriate graphs similar to Figure 3. Owing to the low level at which the oxygen uptake becomes dependent on oxygen tension, the data on which the descending portions of these curves are based are rather meager and no precise accuracy is claimed for them such as was attained by Maloeuf (1937) in his investigations. In particular, the curve determined at 20° C. is not consistent with the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. OXYGEN CONSUMPTION IN GOLDFISH 71 oxygen uptake is plotted gainst oxygen tension. These curves were derived by tak- ing tangents from the appropriate graphs similar to Figure 3. Owing to the low level at which the oxygen uptake becomes dependent on oxygen tension, the data on which the descending portions of these curves are based are rather meager and no precise accuracy is claimed for them such as was attained by Maloeuf (1937) in his investigations. In particular, the curve determined at 20° C. is not consistent with the trend of the remaining data. However, although the proportional error may be considerable, the absolute error must be of no great order since the range of ten- sions occupied by this portion of the curve is in all cases less than 40 mm. u o 10 C o o 01 CP ITI X. -35 •20° •15° -10° . s° _L _L _L ao eo Tension so mm. aoo FIGURE 4. The relation of the maximum steady rate of oxygen consumption to oxygen tension at various temperatures. While the physiological significance of the phenomenon commonly known as respiratory dependence has been often discussed at length since the beginning of the century, its ecological implications do not appear to ever have been clearly stated, except in connection with man in the case of the conquest of Mount Everest (Hen- derson, 1939). The data in Figures 2 and 4 appear to us to offer two physiological indices that may be of great use to the ecologist. These have been designated by Fry (1947) as "the incipient limiting level" and "the level of no excess ; The incipient limiting level is that level of oxygen tension below which the rate of oxygen uptake at the maximum steady state of activity begins to be reduced. This is the point of inflection of the curves in Figure 4. The incipient limiting levels of oxygen tension thus determined for the goldfish are given in Table I. The point of inflec- tion in Toryu's dat
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
