Longamoebia

Thecamoeba, a flattened naked amoeba with a cell covering of thick mucoprotein, which is thrown up into longitudinal folds. Locomotion is monopodial. The broadly rounded pseudopod has a prominent hyaline cap. Crystalline cytoplasmic inclusions and a large posterior contractile vacuole are seen in this image. The morphology of the nucleus, important for species identification, is not well seen here. From fresh water pond near Boise, Idaho. Phase contrast.

Acanthamoeba (a-can-tha-me-ba), collection of cysts. Irregular shape of cyst wall and with pores is characteristics of this and closely related genera. Differential interference contrast.

Acanthamoeba (a-can-tha-me-ba), fine extensions are referred to as subpseudopodia, because they emerge from the hyaline cap. Anterior is to north. Nucleus with dark nucleolus is in the centre of the cell. Large vacuole near base of cell is the contractile vacuole. Phase contrast.

Acanthamoeba (a-can-tha-me-ba), detail of hyaline cap with subpseudopodia. Nucleus also evident. Differential interference contrast.

Protacanthamoeba (prote-a-can-tha-me-ba), free-living lobose amoeba with extensive hyaline zone and fine subpseudopodia arising from the margins of the cell. Trophic cells and cysts, contractile vacuole and nuclei visible in both. Phase contrast.

Balamuthia (bah-lah-moo-thee-a) is an amoeba which was first isolated as an infectious agent of primate (not human) brains. Irregular appearance. Differential interference contrast.

Balamuthia (bah-lah-moo-thee-a) is an amoeba which was first isolated as an infectious agent of primate (not human) brains. Irregular appearance. This image shows various cysts. Differential interference contrast.

Comandonia (come-and-own-ee-a) - one of the acanthamoebid amoebae, with a hyaline region from which some fine subpseudopodia may emerge. This cell has a well developed hyaline region and the contractile vacuole is also evident. Distinguished by leaving the cyst through an operculum. Phase contrast.

Description: Amoeba with a pellicle-like surface noticeable by a rather stiff appearance and, in this case, numerous wrinkles. Movement with a tractor-like rolling of the surface.  Size of locomotive form in this specimen 90x70 µm. Hyaloplasm as an antero-lateral crescent. Contractile vacuole located in posterior end of the cell. Nucleus spherical to ovoid, nucleolus of granular texture (see picture in lower right angle), sometimes divided in 2 or 3 fragments. Phase contrast ; nucleus in modified phase contrast. Amoeba was cultured in filtered water from original habitat and fed with Oscillatoria (Cyanobacteria), rests of which are seen in a food-vacuole in the centre.  It is one of the rugose species of the genus as described by Page and one of the typical representatives of Smirnov’s rugose morphotype.  A future zip-file may contain tables showing the peculiar phagocytosis of oscillatoria by Thecamoeba sphaeronucleolus as well as the fusion of two cells followed by encystment and cell division.  

Description: Amoeba with a pellicle-like surface noticeable by a rather stiff appearance and, in this case, numerous wrinkles. Movement with a tractor-like rolling of the surface.  Size of locomotive form in this specimen 90x70 µm. Hyaloplasm as an antero-lateral crescent. Contractile vacuole located in posterior end of the cell. Nucleus spherical to ovoid, nucleolus of granular texture, sometimes divided in 2 or 3 fragments. Phase contrast. Amoeba was cultured in filtered water from original habitat and fed with Oscillatoria (Cyanobacteria), rests of which are seen in a food-vacuole in the centre.  It is one of the rugose species of the genus as described by Page and one of the typical representatives of Smirnov’s rugose morphotype.  

Description: Amoeba with a pellicle-like surface noticeable by a rather stiff appearance and, in this case, numerous wrinkles. This image shows the nucleus at higher magnification (in the centre). It is spherical to ovoid, the nucleolus of granular texture, sometimes divided in 2 or 3 fragments. In the upper right corner a part of the contractile vacuole can be seen.  Modified Phase contrast.