This dataset contains the experimental data presented in the paper “Mussel seed is highly plastic to settling conditions: the influence of waves vs. tidal emergence”. The dataset contains morphological and behavioral parameters of mussels subjected to different hydrodynamic conditions in a mesocosm experiment. This study tested i) to what extent are mussel-seed coming from collectors in the water column still capable of adjusting their phenotype, and ii) is exposure to air or wave action more important as a driver of phenotypic adjustments for mussels living in intertidal conditions?