part of develops_from vegetative amoebae DDANAT:0000002 Dictyostelium_discoideum_anatomy Unicellular haploid myxamoebae that feeds on bacteria by phagocytosis and divides by binary fission. The size of vegetative cells range from 12-20 microns by 8-12 microns. The cells exhibit a roughly rounded but rather irregular shape. amoebae vegetative cell stream Dictyostelium discoideum single cell organism spore