To elucidate how reef-building corals respond and/or resist to OA, three levels of pCO2 (350.06 ± 30.67, 818.93 ± 76.09, 1694.92 ± 105.77 μatm) were used to mimic OA in ambient seawater to culture A.gemmifera larvae and juveniles. Developmental states and growth were recorded and gene expression were compared between corals in the three treatments at 3 days post-settlement (d p.s.) (short-term) and 40 d p.s. (long-term).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 extracted from tables in the related paper (see Related to) 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 2025-09-23.