Amoeba (plural = amoebae) is well known as a unicellular organism, a protist. One of its most common species, the Amoeba Proteus is about 0.2 to 0.3 mm large. Some found are 0.5 mm large, big enough to be seen with the naked eye. The amoeba was first discovered by August von Rosenhof in 1757. Amoeba doesn't have a fixed body-shape and it appears similar to blobs of jelly-like substance. By constantly changing its shape, the amoeba creates body extensions known as pseudopods - which assist in locomotion. The amoeba can also gather food with the help of these pseudopods. The process through which food is consumed by amoeba is referred to as phagocytosis. Important body components of these unicellular organisms include the nucleus, cytoplasm and vacuole. The amoeba is a member of a whole group of amoeboid eukaryotic protists. They are heterotrophs, eating bacteria and other protists. Amoebae are often found within freshwater, typically on vegetation in decay in still or slow moving water, or in the benthic zone of some lakes.