Amoeba, Amoeboflagellate, Cyst, Discoba, Excavata, Extremophile, Flagellate, Heterolobosea, Naegleria, Pathogen, Protozoa, Slime mold

Heterolobosea is a group of ~150 described species of heterotrophs, almost all free living. Many are “ amoebo flagellates” with a three-phase asexual life cycle, centered on trophic amoebae that can reversibly transform into flagellates (some of which undertake phagocytosis and/or division) and cysts. The amoebae are usually lobose, with “eruptive” pseudopodia. Flagellates typically have two or four near-parallel flagella and, if phagocytic, a feeding groove and/or elongate cytostome. Some taxa have simpler lifecycles, for example, Vahlkampfia spp. apparently lack flagellates, while Percolomonas and Stephanopogon lack amoebae. Stephanopogon ,uniquely, has numerous flagella in rows like the kineties of ciliates. Acrasids, meanwhile, areterrestrial “slime molds” in which amoebae aggregate to form stalked fruiting bodies. The mitochondria are often enveloped in endoplasmic reticulum and usually have discoidal cristae, while the Golgi apparatus lacks dictyosomal stacking. Most flagellates have a “doubled” flagellar apparatus with two sub-identical halves. The flagellar apparatus typically includes a large“R2”microtubular root (or two) and a striated rhizoplast.