Abstract Symbiont-bearing large benthic foraminifers (LBFs) are widely distributed around coral reefs. If the physiological responses of LBFs to environmental changes can be recognized at an individual level, LBFs could serve as highly accurate bioindicators. In this study, chlorophyll a, respiration, and photosynthesis of Baculogypsina sphaerulata individuals were measured, and whether thes…