The freshwater mussel Limnoperna fortunei is adapted to colonize a wide range of aquatic environments, and its ability to contend with environmental stress through phenotypic plasticity has allowed this species to successfully colonize and become established in new regions. Only limited information is currently available on the wide intraspecific variability of this species in response to environmental heterogeneity. Here, we tested the hypotheses that (1) growth and body weight of mussels from a highly polluted environment differed from those from a less polluted habitat, and (2) growth parameters estimated in this study differed from those reported for other invaded ecosystems. We conducted controlled field experiments in two study sites with differing levels of pollution. To compare our results to those reported elsewhere, we considered growth data from studies performed in different locations. We found that mussels from the more polluted habitat showed lower shell growth and body weight than those from the less polluted environment. We also observed differences in the growth performances of the golden mussel between our estimates and those from other invaded habitats. Our findings provide useful information to better understand the striking intraspecific variability of this species in response to stressful conditions. Knowledge on the phenotypic plasticity of L. fortunei is essential for predicting and managing this species.