COMPARATIVE-STUDY ON THE BEHAVIORAL, VENTILATORY, AND RESPIRATORY RESPONSES OF HYPOGEAN AND EPIGEAN CRUSTACEANS TO LONG-TERM STARVATION ANDSUBSEQUENT FEEDING

Survival, oxygen consumption, locomotory activity and ventilatory acti vity were recorded during a 180-day starvation period and a subsequent 15-day feeding phase in 3 hypogean crustaceans, Niphargus rhenorhodan ensis, Niphargus virei, and Stenasellus virei. For comparison, these p arameters were also recorded during a 28-day starvation period and a s ubsequent 7-day feeding phase in two morphologically close epigean cru staceans, Gammarus fossarum and Asellus aquaticus. Hypogean crustacean s were better adapted to lack of food than epigean ones and all crusta ceans previously studied, with survival times largely longer than 200 days. During long term starvation, the locomotory, ventilatory, and re spiratory rates were drastically lowered in subterranean species, wher eas surface species showed lower decreases in these rates and responde d by a marked and transitory hyperactivity. The higher reduction in me tabolic rate by hypogean species would ensure their survival during pr olonged periods of food deprivation. We propose an energy strategy for food-limited hypogean crustaceans involving the ability 1) to withsta nd long-term starvation, and 2) to use the consumed food very efficien tly. Resistance to starvation would probably involve a state of tempor ary torpor during which the subterranean crustaceans subsist on a high energy reserve, such as lipid stores.