Photosynthetic plasticity of endosymbionts in larger benthic coral reef Foraminifera

► Photosynthetic performance of all endosymbionts in Foraminifera is shown for the first time. ► Photosynthetic yields of endosymbiotic algae are similar to their free-living counterparts. ► Photosynthetic yields undergo light-driven fluctuation under experimental light. ► All Foraminifera acclimatize to changing light conditions in the short-term.