Title: Test No. 220
Description: This Test Guideline is designed to be used for assessing the effects of chemicals on the reproductive output of the enchytraeid worm, Enchytraeus albidus Henle 1873, in soil. Adult enchytraeid worms are exposed to a range of concentrations of the test substance mixed into an artificial soil. Ten worms are randomly allocated to each test vessel. A range-finding test should be used, for two weeks, in case of no sufficient information. The duration of the definitive test is six weeks. At the end the total number of juveniles produced by parent animal and the survival of parent animals are assessed. The limit test corresponds to one dose level of 1000 mg/kg. The study report should include the adult morphological changes, the number of offspring. The reproductive output of the animals exposed to the test substance is compared to that of the control(s) in order to determine the no observed effect concentration (NOEC) and/or ECx by using a regression model to estimate the concentration that would cause a x % reduction in reproductive output. The test concentrations should bracket the ECx so that the ECx then comes from interpolation rather than extrapolation.
Subjects: Ecology, Euthenics, Nature and nurture, Adaptation (Biology)