Polyester bags used to keep replicates during the non-aquatic exposure showed a mean air temperature (◦C) and relative humid-ity (%RH) of 19.7 ± 0.7◦C and 66.8 ± 9.5%, respectively (n = 308).When animals were left in leaf litter, 0% survival was reached after 3 days of exposure, while in sediment and clay it was reached after 5 days of non-aquatic exposure (Fig. 2). Survival did not significantly differ between sediment and clay (GLM treatment p = 0.19, par-tial regression coefficient for sediment vs clay treatment = −0.69)although snails in sediment died at a faster rate. The highest sub-stratum moisture was found in leaf litter and was similar between sediment and clay (LM treatment p < 0.001, partial regression coef-ficient for treatment = −0.72; pairwise t test between sediment and clay of p = 1, and between clay and leaf litter, and between sediment and leaf litter of p < 0.01) (Fig. 3). However, moisture lost was faster in leaf litter than in the other treatments as leaf litter lost around 80% of humidity during the first three days. In all cases, moisture decreased with time (LM time p < 0.001, partial regression coeffi-cient for treatment = −0.59) (Fig. 3), which is especially remarkable during the first three days. Only one animal died among those (90)used as controls showing that handling was not the cause of death.