OECD 242: Potamopyrgus antipodarum Reproduction Test

So far most ecotoxicological tests with invertebrates are conducted with arthropods. There is a need to consider other groups of animals for the assessment of chemicals. Molluscs are suitable for testing because of their ecological significance and their sensitivity towards chemicals. The review paper on Molluscs Life-cycle Toxicity Testing (OECD 2010) summarizes the responses of molluscs to endocrine disrupting chemicals and recommends a partial life cycle test assessing effects on reproduction and survival of the freshwater mudsnail Potamopyrgus antipodarum over 28 days.

Test Organisms

P. antipodarum is a very small (3 - 5 mm) freshwater snail endemic in New Zealand and invasive in many countries all over the world. Laboratory cultures reproduce parthenogenetic while in their ancestral distribution area populations have an almost balanced ratio of males and females. Build embryos are released through the female aperture when the egg shell tears open. This kind of reproduction is called ovovivipary.

Course of the test

Adult snails are exposed to a concentration range of the test chemical for 28 days. Afterwards survival and the number of embryos in the brood pouch is determined without the distinction of the developmental stage.


  • main endpoint is the effect of the chemicals on embryo numbers expressed as X percent Effect Concentration (ECX)
  • alternatively as the No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC).

Guidelines and Literature

  • OECD Guideline 242: Potamopyrgus antipodarum Reproduction Test.