In dinoflagellates: phototrophy, mixotrophy, and heterotrophy are seen. Phototrophs are often photoautotrophs or auxotrophs. Mixotrophic dinoflagellates are photosynthetically active but also are heterotrophic. Facultative mixotrophs, during which autotrophy or heterotrophy is sufficient for nutrition, are classified as amphitropic. If both forms are required, the organisms are mixotrophic sensu stricto. Some free-living dinoflagellates don't have chloroplasts but host a phototrophic endosymbiont. Food inclusions contain bacteria, blue-green algae, small dinoflagellates, diatoms, ciliates, and other dinoflagellates.