ABSTRACT
Terrestrial arthropods exhibit an array of impressive adaptations for conserving water, including highly waterproof cuticles, the ability to reduce excretory losses by resorption of water from the faeces and, in some species, the ability to absorb water vapour from subsaturated atmospheres (Edney, 1977). The possibility of an additional adaptation has been inferred from the observation that gravimetric water loss rates of many terrestrial arthropods increase significantly following death, even when body openings, e.g. spiracles, are sealed. This increase, which may be as large as five-fold (Toolson & Hadley, 1979), has been interpreted as evidence for an energy-dependent process that actively retards loss of water through the cuticle (Winston & Beament, 1969). The mechanistic basis for the phenomenon, however, is controversial (Berridge, 1970; Riddle, 1981; Machin, Lampert & O’Donnell, 1985).
