Penard Labs

The Fascinating World of Amoebae

Index of Genera

When you click on a link, you may have to scroll down a little to reach the selected taxon.

Glossery of Terms

Acanthopodia: pointed, tooth-shaped pseudopodia.
Algaevorous: feeds primarily or entirely on algae.
Anastomosis: interconnection between different pseudopodia.
Aperture: opening in the test through which cytoplasm can extend.
Athalamid: without a single chamber; no test (= naked Foraminifera).
Axoneme: stiff core of microtubules that forms the skeleton of cilia and axopodia. The microtubular pattern of the axoneme for cilia is identical in all eukaryotic taxa (9x2+2 arangement) and differs within the axopodia of the Centrohelids and within the Actinophryids.
Axopodia: ray-shaped pseudopodia with an axoneme and extrusomes.

Bacterivorous: feeds primarily or entirely on bacteria.
Binucleate: with two nuclei.
Bothrosome: organelle to produce ectoplasmic networks which absorbs nutrients from surrounding environments (Labyrinthulida and Thraustochytrida).

Centrosome: microtubule organizing center (MTOC).
Cilium: eukaryotic flagellum; an intracellular organelle.
Cocolith: calcareous plate-shaped scale; Golgi-derived (Haptomonads).
Cospecific: of the same species.
Crystal: vacuole with crystal of nitrogenous waste products; the form of the crystals is an important trait.
Cyst: vegetative resting stage with a protective wall.
Cytostome: cell mouth; pseudostome.
Cytoplasm: the entire liquid portion of a cell; liquid cytosol, organelles and inclusions.
Cytoproct: cell anus; region where waste material is ejected to leave the cell.

Dactylopodia: finger-shaped pseudopodia (Mayorella, Korotnevella)
Dystrophic: brown- or tea-colored water; high concentration of humic substances and organic acids.

Ectoplasm: gelatinized cortical cytoplasm of an amoeba; used to describe amoeboid movement.
Encystment: forming a cyst or becoming enclosed in a cyst.
Endoplasm: liquid inner cytoplasm of an amoeba; used to describe amoeboid movement.
Endocytosis: transport of material into the cell.
Endosymbiotic bacteria: symbiotic bacteria in vacuoles within the cytoplasm.
Epipodium: plasma projection in shelled amoebae to connect the protoplast with the shell.
Exocytosis: export of material (non-digestible food particles) out of the cell; defecation.
Extrusome: membrane-bound structure that can be extruded (e.g. trichocyst, haptocyst, kinetocyst).
Excystment: emergence from a cyst by local softening the cyst wall or by passing through a pre-formed annulus.
Eyespot: pigmented area; stigma.

Filopodia: fine filamentous pseudopodia, containing no granuloplasm or microtubules, sometimes branching, but never anastomosing.

Glycocalix: cell coat; layer of polysaccharids and proteins anchored in the cell membrane.
Glycogen body: structure composed of the carbohydrate glycogen (animal starch).
Glycostyle: vertical and prismatic structures in the glycocalix of amoebae.
Granuloplasm: cytoplasm with visible inclusions (granules).
Granulopodia: fine filamentous pseudopodia, with granules (extrusomes), sometimes branching and anastomosing.
Granuloreticulopodia: network of reticulopodia with internal bundles of microtubules and granuloplasm; bidirectional plasma streaming (Foraminifera).

Heterotroph: organisms that cannot fix carbon and need pre-formed organic material.
Hyaloplasm: inclusion-free, almost transparent cytoplasm.
Hydrogenosome: membrane-bound organelle in some anaerobic protists; generates H2 to turn oxygen into H2O; of endosymbiotic origin.

Idiosome: self-produced element; used to form a test.
Inclusions: crystals, endosymbiotic bacteria and glycogen bodies.

Kinetocyst: extrusome of heliozoans that is involved in capturing prey.
Kinetosome: basal body; not membrane-bound intracellular organelle with an MTOC where a cilium can emerge.

Lamellipodia: very thin and flat lobopodia.
Lobopodia: more or less broad pseudopodia with cytoplasmic streaming.
Lysotroph: heterotrophic mode were enzymes are released and the resulting soluble nutrition is moved by diffusive transport across the plasma membrane.

Mastigoneme: tripartate tubular hairs arising at right angles to the cilium along its length (Stramenopiles).
Meroplasmodium: form of plasmodium where multiple cells share a common filopodial network.
Microtubule: polar tubular polymers of tubulin.
Mixotroph: organisms that can obtain nutrition by phototrophy or heterotrophy or both simultaneously.
Monopodial: with only a single pseudopodium.
Monothalamic: test with only one chamber (Foraminifera).
Monospecific: a genus with only one known species.
Morphotype: morphodynamic-organization pattern of a cell.
MTOC: microtubule organizing center.

Osmotroph: soluble nutrition is moved by diffusive transport across the plasma membrane.

Periplast: part of a cell, external to the plasma membrane; often composed of scales, plates etc.
Phagotroph: form of nutrition for heterotrophs where solid organic material is ingested by phagocytosis.
Phagocytosis: „cellular eating“; process of engulfing solid food, often with pseudopods; forming a surrounding vesicle (food vacuole) and digesting the food.
Pinocytosis: „cellular drinking“; process of obtaining liquid nutrients by forming a vesicle at the cell membrane.
Plasma membrane: cell envelope; plasmalemma.
Plasmodium: multinucleate cell with mitosis without fission.
Phototroph: organisms that can fix carbon through photosynthesis and need no further pre-formed organic nutrition.
Protoplast: part of a cell that is inside of the plasma membrane.
Pseudostome: cell mouth; cytostome.
Pseudopodium: transient plasma projection for locomotion and/or food uptake.

Reticulopodia: fine anastomosing pseudopodia; containing no granuloplasm; sometimes forming a network.

Scale: Golgi-derived element of specific shape; organic, siliceous or calcareous; used to form a periplast.
Septum: separating wall; partition.
Spicula: delicate, pointed element lying on the plasma membrane; often needle shaped.
Spine: pointed element.
Spore: agent of reproduction.
Statospore: siliceous resting stage produced by some algae (e.g. Chrysophyceae and Synurophyceae).
Subpseudopodium: hyaline projections of different shape, usually anteriorly directed, which do not take part in the relocation of the main cell mass.
Syncytium: multinucleate, mostly large or giant cell; formed by fusion of individual cells.

Tectum: layer of scales covering the dorsal side of the cell ( as in Cochliopodium).
Test: cell covering; shell; theca.
Theca: unspecific term for cell covering.
Trait: property of a taxon.
Trophozoite: active form of a cell.

Uroid: posterior end of an amoeba; the form of the uroid is an important trait.

Xenosome: foreign element; often grains or diatom frustules used for the construction of a test; agglutinated by organic cement.

Zoochlorellae: green algae in vacuoles as intracellular symbionts; often of the genus Chlorella.