Full life-cycle toxicity assessment using rotifer resting egg production: implications for ecological risk assessment

Environ Pollut. 2001;114(3):399-406. doi: 10.1016/s0269-7491(00)00232-3.


The majority of standardized toxicity tests incorporate only a fraction of the test organism's life-cycle. However, in natural ecosystems, organisms may be exposed at various times during their life-cycle or throughout their life-cycle. Thus, ecotoxicological data from standardized toxicity tests is of limited ecological relevance. Existing standardized toxicity tests using the freshwater rotifer Brachionus calyciflorus utilize 24-h survival or 48-h asexual reproduction as endpoints, despite evidence that sexual reproduction is more sensitive. A 96-h B. calyciflorus resting egg toxicity test was developed and used to estimate the toxicity of pentachlorophenol (PCP) and copper. Results were compared to a variety of acute and sublethal endpoints for both toxicants. The B. calyciflorus 96-h resting egg production NOEC for PCP of 10 micrograms/l was 20 times lower than the 48-h asexual reproduction no observed effect concentration (NOEC) and 120 times lower than the 24-h acute lethal concentration 50%. The 96-h resting egg production NOEC for copper of 2.8 micrograms/l was 7 times lower than the 48-h asexual reproduction NOEC and nine times lower than the 24-h acute LC50. Resting egg production was a more sensitive indicator of toxicity than several other sublethal endpoints as well. These results indicate that partial life-cycle toxicity tests are not sufficiently sensitive to detect ecologically relevant adverse effects.

MeSH terms

  • Animals
  • Chlorophenols / toxicity
  • Copper / toxicity
  • Dose-Response Relationship, Drug
  • Ecology
  • Eggs
  • Female
  • Reproduction, Asexual / drug effects*
  • Risk Assessment
  • Rotifera / physiology*
  • Sensitivity and Specificity
  • Survival Analysis
  • Time Factors
  • Toxicity Tests


  • Chlorophenols
  • Copper