Growth inhibition in early life-stage tests predicts full life-cycle toxicity effects of lead in the freshwater pulmonate snail, Lymnaea stagnalis

► The ability of ELS snail survival/growth tests to predict full life-cycle results was investigated using Lymnaea stagnalis exposed to Pb for 56d. ► Snail growth at 28d was more sensitive than at 56d, indicating snails partially recovered from early life stage effects. ► Snail reproduction was effected at the same concentration (1μgL−1) as 28d growth. ► Results indicate 28d growth is predictive (within a factor of 3) of full life-cycle results and should be acceptable for setting WQ standards. The freshwater pulmonate snail, Lymnaea stagnalis, is the most sensitive freshwater organism tested to date for several metals (Co, Cu, Pb, Ni) based on 28d early life-stage (ELS) tests in which growth was the most sensitive endpoint. The United States Environmental Protection Agency (USEPA) has expressed concern that growth in 28d ELS tests with mollusks may overpredict toxicity because of the potential for recovery in a full life-cycle (LC) test. Consequently, the USEPA only accepts the survival endpoint for these tests in establishing water quality criteria (WQC). To address this concern, the current study aimed to test the sensitivity of L. stagnalis to Pb in a 56d full LC test evaluating survival, growth, reproductive and embryonic growth endpoints and compare the estimated effect levels to those established using the 28d ELS test design. The most sensitive endpoints in this study were 28d growth and 56d egg mass production, both with a NOEC of