Supporting data for "Individual and interactive effects of temperature and salinity on the phenotypic plasticity of the euryhaline seagrass Halophila ovalis"

Environmental temperature plays a central role in modulating the phenotypic variation of seagrasses. These characteristics, however, are also sensitive to temporal and spatial changes in salinity conditions. It remains unclear to what extent the interaction of these factors can regulate variation in the performance and thermal biology of seagrasses. In this study, we assessed the thermal reaction norm for the growth rate of the seagrass Halophila ovalis, investigating the potential influence of salinity on the shape of this non-linear relationship. We found that H. ovalis exhibits the classic thermal performance curve, with a Topt higher (~1°C) than the median summer temperature experienced in its natural habitat. In contrast, a significant decline in performance occurred at lower temperatures (e.g., average winter conditions). No significant effect was detected on the overall shape of this reaction norm likely due to the euryhaline nature of this species.