In this study, we used controlled aquaria experiments to investigate the effects of acidification and elevated temperature treatments on nutrient cycling in the larval hostSymbiodiniaceae symbiosis to elucidate the processes shaping symbiotic interactions. Using P. damicornis larvae harboring Durusdinium spp., we combined physiological measurements of larval performance with stable isotope labeling and analysis to explore the role of carbon and nitrogen assimilation in the symbiosis. First, we tested how experimental acidification (1000 µatm) and elevated temperature (32 °C) affect Symbiodiniaceae density and primary production. Second, we examined the effects of these conditions on larval carbon and nitrogen assimilation.This dataset is included in the OA-ICC data compilation maintained in the framework of the IAEA Ocean Acidification International Coordination Centre (see https://oa-icc.ipsl.fr). Original data were downloaded from FigShare (see Source) by the OA-ICC data curator. In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2024) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2024-12-05.