Supplementary Table 1. Selection differentials (±95% CIs) on size-adjusted shell trait values for (A) uninduced, (B) predator-induced, and (C) uninduced with predator-induced snails. Calculations, formatting and abbreviations follow Table 1.

A / Linear / Nonlinear
Mass / Shell L / Shell W / Aperture L / Aperture W / Shell Thick
Shell L / 0.08±0.43 / 0.32±0.30 / -0.08±0.34
Shell W / -0.28 ±0.39 / 0.19±0.29 / -0.10±0.29 / 0.01 ±0.35
Aperture L / -0.11 ±0.43 / 0.28±0.31 / 0.00 ±0.30 / 0.05±0.32 / 0.16±0.30
Aperture W / 1.47±0.41 / 0.94±0.51 / 0.09±0.68 / -0.44±0.63 / -0.10±0.70 / 2.35±1.24
Shell Thick / 1.01±0.26 / 0.45±0.36 / -0.20±0.48 / -0.52±0.44 / -0.42 ±0.47 / 1.21±0.59 / 0.98±0.55
B / Linear / Nonlinear
Mass / Shell L / Shell W / Aperture L / Aperture W / Shell Thick
Shell L / 0.68±0.31 / 0.14±0.23 / 0.78±0.46
Shell W / 0.40±0.33 / 0.18±0.20 / 0.66±0.33 / 0.63±0.37
Aperture L / 0.62±0.35 / 0.10±0.24 / 0.81±0.38 / 0.74±0.33 / 0.89±0.49
Aperture W / 2.32±0.38 / 0.45±0.59 / 1.83±0.79 / 1.34±0.83 / 1.72±0.88 / 5.72±1.81
Shell Thick / 0.28 ±0.28 / -0.03±0.16 / -0.13±0.28 / -0.23±0.24 / -0.19±0.28 / 0.47±0.71 / 0.21±0.41
C / Linear / Nonlinear
Mass / Shell L / Shell W / Aperture L / Aperture W / Shell Thick
Shell L / 0.04±0.42 / 0.00±0.56 / 0.53±0.40
Shell W / -0.31±0.41 / -0.15±0.56 / 0.28±0.34 / 0.41±0.50
Aperture L / -0.20±0.44 / -0.14±0.60 / 0.50±0.37 / 0.47±0.35 / 0.75±0.50
Aperture W / 1.33±0.52 / 1.68±0.90 / 0.46±0.70 / -0.06±0.70 / 0.19±0.76 / 2.78±1.46
Shell Thick / 0.94±0.35 / 0.99±0.56 / -0.26±0.47 / -0.44±0.47 / -0.48±0.50 / 0.89±0.76 / 0.81±0.78

Supplementary Figure 1. Induction effects of predator cues on mass-adjusted trait values are shown as the grand mean of tub means (± 1 S.E.) of our initial samples (i.e., snails that were reared in the presence or absence of crayfish cues, brought into the lab, but not exposed to lethal predators). Individual trait values were transformed prior to analysis (see text for details), and tub means were back-transformed to present values on their original scale (mm). Inset test results show the results of one-way ANOVAs conducted on mass-adjusted data; dfs are the same for all tests.