Euglena is connecting link between plant and animal and has mixotropic mode of nutrition. In presence of sunlight they are photosynthetic and in absence of light they show holozoic nutrition. They are biflagellate having two unequal flagella. They are surrounded by protein rich layer called as a pellicle. When acting as a heterotroph, the Euglena surrounds the particle of food and consumes it by phagocytosis, or in other words, engulfing the food through its cell membrane. Euglena are considered mixotrophs, autotrophs in the light and heterotophs in the dark.
