An antioxidant, sodium hypophosphite (SHP-1 X 10(3) microM), when added to the diet of Zaprionus paravittiger, induces various shifts in the age-related biochemical parameters. It maintains the viability of protein synthesis and normal energy-yielding processes through longer intervals besides decelerating the rate of loss of nucleic acids (Sharma and Wadhwa, 1986). Reduced body weight which indicates the low level of food restriction, and adaptive changes in amino acids and proteins, could be the important factors for the favourable effect of this antioxidant on life span.