Penard Labs

The Fascinating World of Amoebae
Choanoflagellates
Unikonta:
AMOEBOZOA Lühe 1913 emend. Cavalier-Smith 1998
Cells naked or testate; uni-, bi- and multinucleate; cysts common; sexual or asexual; pseudopodia of the lobopodia type.
Tubulinea Smirnov et al. 2005
Tubular, sub cylindrical pseudopodia or capable of altering the locomotive form from a flattened, expanded one to a sub cylindrical one. Monoaxial flow of the cytoplasm in every pseudopodium or in the entire cell.
Discosea Cavalier-Smith et al. 2004
Flattened naked amoeba that never produce tubular, subcylindrial pseudopodia and never alter their locomotive form. Cytoplasmic flow polyaxial or without a pronounced axis. Subpseudopodia short or absent.
Variosea Cavalier-Smith 2004, emend. Smirnov 2011


Aerobic ciliated amoebae with conical microtubular cytoskeleton and only temporary pointed pseudopodia or non-ciliate amoebae with long, tapering, usually pointed, often branched subspseudopodia.
Archamoebae Cavalier-Smith 1983


Anaerobic or microaerobic mostly ciliated amoebae with reduced mitochondrial organelles and endosymbiotic bacteria. Amoeboid movement with eruptive lobopodia. Free-living or endobiotic.
OPISTHOKONTA Cavalier-Smith 1987, emend. Adl et al. 2005
Single posterior cilium without mastigonemes, present in at least one life cycle stage, or secondarily lost.
Nucletmycea Brown et al. 2009
This clade includes Fungi, Fonticula and Nuclearia.
Bikonta:
AH
AH is a clade that contains Archaeplastida (red algae, green algae, and plants) as well as Hacrobia and is based purely on molecular data.
Hacrobia Okamoto and Keeling 2009
Sometimes also called CCTH (Cryptophyta, Centrohelea, Telonemia and Haptophyta).
Centrohelea Kühn 1926

Axonemes insert at a central microtubule organizing center (MTOC); uninucleate, nucleus eccentrically placed; reproduction by binary fission; kinetocysts developed in the rough endoplasmic reticulum; sometimes with cysts and sometimes with a mucous stalk.
SAR Burki et al. 2007
SAR is a clade that contains Stramenopiles (Heterokonts), Alveolata and Rhizaria and is like AH based purely on molecular data.
Stramenopiles Patterson 1989, emend. Adl et al. 2005
Motile cells typically biciliate, typically with heterokont ciliation – anterior cilium with tripartite mastigonemes in two opposite rows and a posterior usually smooth cilium.
Actinophryidae Dujardin 1841

Axonemal pseudopodia emerging from amorphous centrosome near nuclei; axonemal microtubules; single central nucleus or several peripheral nuclei; two types of extrusomes for prey-capture along axopodia; cysts covered with siliceous elements; autogamy reported within cysts.
Chrysophyceae Pascher 1914

Predominately ciliated cells, swimming cells biciliated – one anteriorly directed and one laterally directed; cell coverings, when present, include organic scales, silica scales, organic lorica, and cellulose cell wall; eyespots present or absent.
Synurales Andersen 1987

Predominately ciliated cells, benthic palmelloid colonies known; swimming cells usually with two anteriorly directed cilia – one bearing tripartite tubular hairs with short and long lateral hairs on their shafts. Cells covered with bilaterally symmetrical silica scales; stigma absent.
Dictyochophyceae Silva 1980

Single cells, colonial ciliated cells or amoebae; swimming cells usually with one cilium, anteriorly directed. Cells naked, with organic scales or with siliceous skeleton; eyespots absent.
Mainly osmotrophic cells capable of producing an ectoplasmic network of branched, anastomosing, wall-less filaments via a specialized organelle known as the bothrosome; Golgi-derived scales; biciliate zoospores with lateral insertion in many species.
Rhizaria Cavalier-Smith 2002
With fine pseudopodia varying as simple, branching, or anastomosing patterns (filopodia), often supported by microtubules.
Cercozoa Cavalier-Smith 1998, emend. Adl et al. 2005
Ancestrally biciliated and/or amoeboid, usually with filopodia.
Glissomonadida Howe & Cavalier-Smith 2009, emend. Hess et al. 2013
Small (<15 µm), naked biciliated cells, bacteri- or algaevorous, not strongly amoeboid.
Granofilosea Cavalier-Smith and Bass 2009
With very delicate filopodia bearing frequent regular extrusomes (reticulopodia).
Thecofilosea Cavalier-Smith 2003, emend. Cavalier-Smith 2011
Robust organic extracellular theca unlike other Cercozoa which are usually naked or with scales; ventral filopodia emerge from ventral groove.
Vampyrellida West 1901, emend. Hess et al. 2012
Exclusively heterotrophic, naked, phagotrophic amoeboid organisms; life cycle includes amoeboid, free-moving trophozoites alternating with an obligatory digestive cyst, in which cell division usually take place; several taxa can fuse to form plasmodia and reach considerable sizes; sexual processes unknown; cytoplasm often differentiated into a finely granular, sometimes highly vacuolated part and structure-less hyaloplasm, the latter often surrounding the main cell body, but at least constituting the pseudopodia.
Imbricatea Cavalier-Smith 2012
Cells with secreted surface silicious scales.
Retaria Cavalier-Smith 2002
Mainly marine heterotrophs, with reticulopodia or axopodia, and usually having various types of skeleton.
Foraminifera d’Orbigny 1826
Filopodia with granular cytoplasm, forming branching and anastomosing network (reticulopodia); bidirectional rapid (10 mm/s) transport of intracellular granules.