Protozoa

Protozoa

Traditionally the animal kingdom has been divided into two subkingdoms; Protozoa* and Metazoa* .

Protozoa are the most abundant animals in the world in terms of numbers and biomass. Their principal importance is as consumers of bacteria (PROKARYOTES ). Bacteria play a vital role in maintaining the earth as a suitable place for inhabitation by other forms of life and protozoa play a vital role in controlling their numbers and biomass. Protozoa are also important as parasites and symbionts* of multicellular animals.

Protozoa are defined as single-celled eukaryotic* organsims, that feed heterotrophically* and exhibit diverse motility mechanisms. However, it is impossible to draw a line between unicellular animals (consumers), plants (producers) and fungi (decomposers) and it is customary to speak of the Protista* as a separate kingdom of unicellular eukaryotes that embraces both heterotrophic protozoa and autotrophic algae.