Sea Stars: digits correspond to arbitrary numbers used to identify individual Pisaster ochraceus. Replicate: refers to the three two-week blocks during which we ran our mesocosm predation trials. Survival: whether individual Chlorostoma funebralis survived (1) or perished (0) during their two week mesocosm predation trial. Activity Level: refers to the distance (cm) individual snails traversed over the designated time interval. N Max: normalized maximum shell diameter for our experimental population. N Anti-pred: normalized predator avoidance response for our experimental population.