N. scintillans is a heterotroph (nonphotosynthetic) that engulfs by phagocytosis food which includes plankton, diatoms, other dinoflagellates, fish eggs, and bacteria. Diatoms are often found in the vacuoles (internal membrane-bound storage compartments) within these single-celled creatures. These green nonfeeding symbioses can grow photoautotrophically for generations.[2] Diatoms of Thalassiosira have been noted as a favored food source of these organisms.