. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACCOMMODATION TO OSMOTIC PRESSURES 381 The final weight rise beginning at 16 per cent appeared to be due to the breakdown of the osmoregulatory mechanisms, and was characterized by the intake of large amounts of water which made the animals turgid. Up to this point the animals remained firm with no sign of excess water either in the coelom or the integument. The results of the oxygen consumption measurements show much more variation between individual worms. This is probably due to differences in the amount of activity. A ra
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACCOMMODATION TO OSMOTIC PRESSURES 381 The final weight rise beginning at 16 per cent appeared to be due to the breakdown of the osmoregulatory mechanisms, and was characterized by the intake of large amounts of water which made the animals turgid. Up to this point the animals remained firm with no sign of excess water either in the coelom or the integument. The results of the oxygen consumption measurements show much more variation between individual worms. This is probably due to differences in the amount of activity. A rather definite trend of the averages is evident, however, and this is correlated with the weight I I l I I I I I I 1 I 1_1—L_l. 100 FIG. 3. Effects of diluted sea water on the weight and oxygen consumption of Nereis virens. Left hand ordinates represent total weight of five worms in grams; right hand ordinates represent average cu. mm. oxygen per gram per hour. Abscissa; percentage concentration of sea water. Continuous line represents read- ings as animals were carried from 100 per cent sea water to 4 per cent. Dashed line represents the reverse experiment. curve. With moderate dilutions the weight remained constant, but oxygen consumption rose 33 per cent. In the experiment described below a corresponding but much sharper decrease in oxygen consump- tion was found as the worms were returned to normal sea water. We believe that the increased oxygen consumption in dilute sea water repre- sents the expenditure of energy for osmotic work. Below the critical range of 28 to 16 per cent sea water there was a decrease in the amount of oxygen used per gram per hour. Since weight was increasing dur- ing this period it is difficult to separate the decrease due to the intake of metabolically inactive water from that which may be expended in Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colora
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
