Symbiotic relationship

Sea anemones also maintain a symbiotic relationship with single-celled photosynthetic organisms [inside their cells} called that provide most of their food [glucose]. The color of sea anemones [and corals} is due to the photosynthetic pigment in these intracellular organisms. Bleaching of the coral reef [and their demise] is due to the death of these organisms that provide most of the food for corals and sea anemones.