OECD 243: Lymnaea stagnalis Reproduction Test

Molluscs are an important group for ecotoxicological testing due to their ecological significance and 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 testing with the hermaphrodite freshwater snail Lymnaea stagnalis. An OECD test guideline describing a 28 days reproduction and survival test for this species is available since 2016.


Test Organisms

L. stagnalis is a very common freshwater snail distributed in the northern hemisphere. The hermaphrodite can self-fertilize but cross fertilisation is common. 

Course of the test

Reproducing adult snails are exposed to a concentration range of the test chemical for 28 days. During the course of the test, survival and the number of egg-clutches is determined.


  • Main endpoint is the cumulated number of egg-clutches produced per snail during a 28-day exposure.
  • Snail growth (e.g., increase in shell length) and the number of eggs produced per snail can be used as additional test endpoints.
  • The toxic effect of the test chemical is expressed as X percent Effect Concentration (ECx).
  • Alternatively, the toxic effect of the test chemical can be expressed as the No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC).

Guidelines and Literature

  • OECD Guideline 243: Lymnaea stagnalis Reproduction Test