. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 1 0 20 40 60 80 100 120 140 160 180 Time (h) Figure 1. Time course of changes in ECF osmolality (upper panel) and body water content (lower panel) in Anodonta grandis simpsomana during 144 h emersion and 24 h reimmersion in pondwater at 10°C. Symbols are mean values for five clams; bars are standard errors of the mean. Asterisks indicate values significantly different from control (P < ). The arrows indicate the time of reimmersion in pondwater. Osmolality = (±) + (±) X emersion time (h) (±SE;R: = 0
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 1 0 20 40 60 80 100 120 140 160 180 Time (h) Figure 1. Time course of changes in ECF osmolality (upper panel) and body water content (lower panel) in Anodonta grandis simpsomana during 144 h emersion and 24 h reimmersion in pondwater at 10°C. Symbols are mean values for five clams; bars are standard errors of the mean. Asterisks indicate values significantly different from control (P < ). The arrows indicate the time of reimmersion in pondwater. Osmolality = (±) + (±) X emersion time (h) (±SE;R: = ; df = 1, 38) This translates to an increase in osmolality of approxi- mately 2 mOsm kg ' d~'. Reimmersion resulted in return of water weight to control within 2 h. ECF osmolality declined to control within 6 h of resubmergence. During the first hour of emersion the clams displayed a significant decline in ECF P0,; thereafter, a further, but slower decrease occurred over the course of the emersion period (Fig. 2). Values remained above 20 Torr through- out the time that the animals were exposed. During reim- mersion, the ECF was rapidly reoxygenated, but not to pre-emersion controls values, even after 24 h of resub- mergence. ECF Pco, rose steadily during the first 24 h of emersion, reaching ± Torr (Fig. 2). Thereafter, PCO; contin- ued to rise, but at a slower rate, and after 96 h of emersion values stabilized near 13 Torr. On reimmersion, ECF Pco, declined to pre-emersion values within 6 h of resub- mergence. Emersion resulted in an ECF acidosis, with pH falling significantly below pre-emersion values after the clams had been in air for 7 h (Fig. 2). Although the acidosis was progressive, the rate of pH decline slowed after 24 h and reached a seemingly stable level near ; there it remained until the end of the emersion period. But the steady pH is misleading, as [H+] continued to rise until 96 h after the onset of emersion; then it remained unchanged. ECF p
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
