How does the nutritional process of euglena go green?

Euglena green refers to animals that have the ability to autotrophic and heterotrophic nutrition. It depends on the presence of light. Being an autotroph, euglena uses photosynthesis in the light. With the participation of chlorophyll in the synthesis process, organic substances are formed to feed the animal. At a time when there is not enough light, the animal becomes a heterotroph. It absorbs organic matter in the water. Since euglena green loves prefers dirty stagnant reservoirs, it is quite enough food.