. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. -80 - -100 10 -20 - -40 - -60 - -80 - -too B. Initial Weight (g) o 123 » 294 • 186 a 211 ' 275 • 478 5 Day 10 Figure 2. Cumulative change in weight of specimens exposed to the dehydration of a simulated tidal stranding of 12 h and then returned to stable seawater. All regained weight with their re-establishment of osmotic equilibrium after return to seawater. (A) Intact animals (n = 6). (B) Madreponte-obstructed animals (n = 6). After the first day, intact animals (A) show 41 daily periods of gain and 13 loss; test animals (
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. -80 - -100 10 -20 - -40 - -60 - -80 - -too B. Initial Weight (g) o 123 » 294 • 186 a 211 ' 275 • 478 5 Day 10 Figure 2. Cumulative change in weight of specimens exposed to the dehydration of a simulated tidal stranding of 12 h and then returned to stable seawater. All regained weight with their re-establishment of osmotic equilibrium after return to seawater. (A) Intact animals (n = 6). (B) Madreponte-obstructed animals (n = 6). After the first day, intact animals (A) show 41 daily periods of gain and 13 loss; test animals (Bl 10 minor gains, 39 loss, and 5 no change. The minor gains in the latter group might be due to seal leakage, fluid taken into the stomach, or residual osmotic factors. four similarly treated normal animals. After 12 h of de- hydration, their coelomic fluid osmolality (mean ± ) was elevated ± mosmol kg'1 () above am- bient seawater. while their weight (mean ± ) had dropped ± g (). After 12 h of reimmersion in seawater, their coelomic fluid osmotic level had equil- ibrated to within ± mosmol kg"1 () of ambient seawater, but their weight was still ± g () below the initial mean. Thus, they had gained some water in recovery, but had mainly lost osmolytes. All the control animals quickly assumed normal behavior once they were back in seawater. They then showed 41 daily intervals of weight gain and 13 of loss. The test group (Fig. 2b), like the control animals, also rapidly recovered some weight in seawater. in correspondence with the period of osmotic readjustment. Thereafter, while the control animals gained and fluctuated in weight daily, the test group mostly lost weight: 39 instances to 10 minor gains and 5 instances of no change. The episodes of minor weight gain were ob- served in 2 of the 6 test animals and could have been caused by leakage around the madreporite seals, fluid taken into the stomach, or
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
