The effect of lipids on transepidermal water permeation in snakes

Transepidermal water permeation was measured for the shed skin of 8 species of snakes under conditions where the skin formed an interface between liquid water and dry air. Extraction with chloroform: methanol removed lipids amounting to 4.9-8.7% of the dry weight of skin and increased transepidermal water permeation 35- to 175-fold. Initial extraction of snake skin with hexane removed only 25-35% of the total extractable lipid but increased water permeation 3- to 10-fold. For totally delipidized skin, water-to-air permeation was much faster than air-to-air permeation, and was also faster than evaporation from a free water surface.