Effects of DDT and dicofol on life table demography of the freshwater rotifer Brachionus calyciflorus pallas

Abstract

DDT and dicofol are two typical persistent organic pollutants and raise great concerns around the world because of their resistance to decay in the environment. Little is known regarding their effects on life table variables of rotifers, including age at first reproduction, life expectancy at birth, net reproductive rates, generation time, life span, the intrinsic rate of population increase, and finite rate of increase. In the present study, the effects of DDT and dicofol on survival and reproduction of the rotifer Brachionus calyciflorus were investigated using life table demography. The results showed that treatments with 0.32-1.28 mg/L DDT and 0.64-1.28 mg/L dicofol significantly declined the age-specific survivorship of rotifers. Treatments with 0.32 and 0.64 mg/L DDT and 0.32-1.28 mg/L dicofol significantly prolonged the juvenile period of rotifers. Treatment with 0.08 mg/L DDT significantly prolonged survival time of rotifers. All tested life table variables of rotifers, except generation time, were significantly influenced by DDT and dicofol at concentrations of 0.08-1.28 mg/L. In addition, DDT revealed far greater negative impacts on life table demographic variables of rotifers in comparison to dicofol.