. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. WATER AND SALT REGULATION IX CRABS 451 other hand. Figure 1 shows thai Hemigrapsus can hyporegulate in concentrated sea water. This is contrary to the findings of Jones (1941). However, this conflict of findings has been explained by Gross (l(>63b). Thus. Figure 1 and Table II demonstrate that all crabs examined, showing some degree of t'errestrialness, are hypoosmotic regulators as well as hyper- osmotic regulators. This confirms and expands a phenomenon first reported by Jones (1941). Also, it will be noted that there i
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. WATER AND SALT REGULATION IX CRABS 451 other hand. Figure 1 shows thai Hemigrapsus can hyporegulate in concentrated sea water. This is contrary to the findings of Jones (1941). However, this conflict of findings has been explained by Gross (l(>63b). Thus. Figure 1 and Table II demonstrate that all crabs examined, showing some degree of t'errestrialness, are hypoosmotic regulators as well as hyper- osmotic regulators. This confirms and expands a phenomenon first reported by Jones (1941). Also, it will be noted that there is some correlation between degree of hypoosmotic regulation and the degree of terrestrialness. This corre- lation as illustrated in Figure 1 is far from perfect, for G'ccarciuns. which un- o -5. o <D O O Q O O _J m I50n 140- 130 H £ 120- z o iio- h- ^ 100- LU o 90 80- 70- 60-. 40 50 60 70 80 90 100 110 120 MEDIUM (% Sea water) 130 140 150 160 170 FIGURE 1. Comparative osmoregulatory ability of crabs showing different degrees of terrestrialness. Habitats of crabs are described in text and in Table I. Curves are estimated from mean values in Table II. doubtedly is the most terrestrial, was only the third strongest hyporegulator. Also, it will be recalled that this crab was incompletely immersed in 50% and 150% sea water for only 8 to 10 hours rather than 24 hours. It therefore seems that the ability to osmoregulate in this land crab is not as powerful as indicated in Figure 1. Also, Uca according to Figure 1 does not maintain its blood as low in concentration in hypersalinities as does Ocypodc; still, Uca has been considered to be somewhat more exposed to terrestrial stresses than Ocypode because of its diurnal activity. On the other hand it can be said that the most terrestrial crabs, with the possible exception of Cecarciiins, were stronger hyporegulators for these. Please note that these images are extracted from scanned page images that may have been digitally enhanced fo
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
