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Permeability and Water Relations of Hygroscopic Skin of the File Snake, Acrochordus granulatus

Harvey B. Lillywhite and Veronica Sanmartino
Vol. 1993, No. 1 (Feb. 11, 1993), pp. 99-103
DOI: 10.2307/1446299
Stable URL:
Page Count: 5
Subjects: Biological Sciences Zoology Aquatic Sciences
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Permeability and Water Relations of Hygroscopic Skin of the File Snake, Acrochordus granulatus
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Rates of evaporative water loss were measured in the aquatic file snake Acrochordus granulatus and were used to evaluate permeability and resistance of the skin to evaporative flux in air. Similar measurements were made from a xerophilous terrestrial rattlesnake, Crotalus atrox. The cutaneous water vapor permeability of A. granulatus is high in comparison with other snakes and exceeds that of C. atrox tenfold. The evaporative flux is roughly one-tenth that of a free water film. The granular skin of Acrochordus is hygroscopic and imbibes water which moves rapidly over the body surface through interscalar channels. Consequently, the integument is easily wetted to bear a superficial aqueous film = 5.4 mg water per cm2 of skin surface. Although file snakes are aquatic, they can become entrapped in drying ephemeral pools and have been observed on tidal mud flats where they are potentially exposed to intense heat and dehydration. Superficial water films, therefore, have a potentially important biological role in reducing dehydration of skin or body while extending the time available for terrestrial sojourns between areas of water.

Notes and References

This item contains 21 references.

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