Amoeba are protozoans that consist of a single cell (unicellular). Whilst most protozoans are microscopic, some amoeba can reach 4-5mm. Amoeba proteus achieves a size of around 600µm and has a single disk-shaped nucleus (30µm) and contractile vacuole. It is a carnivore, and feeds on bacteria and other protists.
Protozoans are classified according to their means of locomotion. The shape of Amoeba proteus constantly changes as it puts out false feet (pseudopodia) from any part of its body. The pseudopodia also engulf particles of food (phagocytosis).
Amoeba proteus moves over various substrates such as surface films, moist surface soils, and bottom debris. The requirement is the availability of water.