Effects of low levels of lead on growth and reproduction of the Asian earthworm Perionyx excavatus (Oligochaeta)

The effects of sublethal concentrations of lead nitrate on growth and repro duction of the Asian composting earthworm species Perionyx excavatus was st udied experimentally by exposing worms in an organic substrate to lead nitr ate-contaminated food over a period of 76 days. The results revealed that g rowth was affected negatively by the presence of lead while maturation rate and cocoon production was not affected. In agreement with other studies on Eisenia fetida, cocoon viability was affected negatively by lead, making t his a sensitive toxicity endpoint. Lead accumulation was of the same order of magnitude as for other previously studied species. (C) 1999 Academic Pre ss.