Protozoa: Structure and Locomotor Organelles
The size and shape of protozoa vary based on the types of species. For example, the causative agent of Kala azar, Leishmania donovani has a size range of 1 to 4 micrometers in length, while the Amoeba proteus is 600 micrometers or more in size. Some members of ciliates can reach 2,000 micrometers or 2mm.