Age-related increase of cuticle permeability in the nematode Caenorhabditis briggsae

The external cuticular surface of nematodes, which resembles cellular membranes in certain ways, appears to deteriorate with age. For example, when the permeabilities to radioactive water of young and old nematodes were compared, and the data were corrected for the different surface: volume ratios, the older nematodes were significantly more permeable. In both living and dead nematodes, the same rates of water exchange were observed, indicating that the major route of exchange was probably by passive diffusion through the cuticle rather than by active processes such as swallowing or excreting water.