Amoeba (Ameba)

A single-celled organism that has no rigid body structure. Examples of parasitic amoebae include Entamoeba histolytica (cause of amoebic dysentery) and Naegleria sp. and Acanthamoeba sp. (causes of eosinophilic meningitis). Amoebae usually move around in water and take in food by extending pseudopods.