The Archamoebae are an important group of amoebae.[1] They are unusual among protists because they have no mitochondria.[2]

Entamoeba histolytica 01.jpg
Entamoeba histolytica cyst
Scientific classification

Cavalier-Smith, 1983

The group includes many genera which are internal parasites or commensals of animals: for example Entamoeba and Endolimax. Some are human pathogens, causing diseases such as amoebic dysentery. Other genera of archamoebae live in freshwater habitats, and have flagella. Most have a single nucleus and flagellum, but the giant amoeba Pelomyxa has many of each.

Analysis of 100 genes shows that the Archamoebae are part of the Amoebozoa which have lost their mitochondria. They are close relatives of the slime moulds. Parasitic and commensal forms like Entamoeba and Endolimax developed separately from free-living ancestors.[3]


  1. Cavalier-Smith T 1998. "A revised six-kingdom system of life". Biol Rev Camb Philos Soc. 73 (3): 203–66. doi:10.1111/j.1469-185X.1998.tb00030.x. PMID 9809012.
  2. Cavalier-Smith T. 1991. "Archamoebae: the ancestral eukaryotes?". BioSystems. 25 (1–2): 25–38. doi:10.1016/0303-2647(91)90010-I. PMID 1854912.
  3. Bapteste E; Brinkmann H; Lee J.A. et al 2002. The analysis of 100 genes supports the grouping of three highly divergent amoebae: Dictyostelium, Entamoeba, and Mastigamoeba. Proc. Natl. Acad. Sci. U.S.A. 99 (3): 1414–9. PMID 11830664. [1]