Rhizaria

Vampyrellid filose amoeba. Unidentified, but because it has fine pseudopodia, granular cytoplasm and a tinge of yellow or orange colour it is identified as a vampyrellid amoeba - amoebae which are associated with feeding on fungi and algae in terrestrial and freshwater ecosystems respectively. The terrestrial fungivorous taxa are usually assigned to Arachnula, and the freshwater algivorous species to Vampyrella. Both genera are reported to attach to the outside of their prey, to cut little trap doors in the surrounding walls, and they then throw away the trapdoors before consuming the cytoplasm that then flows out. They have been argued to have potential in controlling some plant pathogenic fungal disorders. Phase contrast.

Arachnula (a-rack-new-la), an amoeboid protist which may develop into very extensive organisms with many nuclei. This image of the cytoplasm shows a large food vacuole, many fine granular inclusions, a number of clear vacuoles and a number of nuclei (with the darker nucleolus inside). Phase contrast.

Arachnula (a-rack-new-la), an amoeboid protist which may develop into very extensive organisms with many nuclei, and with an irregular branching appearance of both cytoplasmic tracts and pseudopodia. This is a typical cell. Phase contrast.

Arachnula (a-rack-new-la), an amoeboid protist which may develop into very extensive organisms with many nuclei, and with an irregular branching appearance of both cytoplasmic tracts and pseudopodia. As can be seen here, the pseudopodia may be thin or spatulate. Phase contrast.

Arachnula (a-rack-new-la), an amoeboid protist which may develop into very extensive organisms with many nuclei. The cysts vary in size and typically have a yellowish colour. Differential interference contrast.

Arachnula (a-rack-new-la), an amoeboid protist which may develop into very extensive organisms with many nuclei. Two cysts, note the hint of yellow colour in the wall, and yellow is a common colour for the vampyrellid / arachnulid amoebae. Phase contrast.

Vampyrella, classified currently with the amoebae of uncertain affinities (formerly included with the filose amoebae). Cells may be rounded with few pseudopodia or more flattened with fine branching pseudopodia. The cytoplasm is orange to pinkish in color with numerous granules, which obscure the nucleus, and contractile vacuole in these images. Vampyrella is algivorous, feeding on filamentous algae. The amoeba drills a small hole in the algal cell wall and consumes the contents. From freshwater pond near Boise, Idaho. Phase contrast.

Vampyrella, classified currently with the amoebae of uncertain affinities (formerly included with the filose amoebae). Cells may be rounded with few pseudopodia or more flattened with fine branching pseudopodia. The cytoplasm is orange to pinkish in color with numerous granules which obscure the nucleus and contractile vacuole in these images. Vampyrella is algivorous, feeding on filamentous algae as seen in this image. The amoeba drills a small hole in the algal cell wall and consumes the contents. From freshwater pond near Boise, Idaho. Phase contrast.

Heteromita (het-err-o-might-a), one of the smaller gliding flagellates, mostly from soils and freshwater habitats. Flattened, two unthickened flagella inserting into a subapical depression in the cell. Anterior flagellum beats with a flopping motion, posterior flagellum drags behind. A cercomonad. There can be considerable variation among cells in a population. Phase contrast.

Heteromita (het-err-o-might-a), one of the smaller gliding flagellates, mostly from soils and freshwater habitats. Flattened, two unthickened flagella inserting into a subapical depression in the cell. Anterior flagellum beats with a flopping motion, posterior flagellum drags behind. A cercomonad. There can be considerable variation among cells in a population. Phase contrast.

Heteromita (het-err-o-might-a), one of the smaller gliding flagellates, mostly from soils and freshwater habitats. Flattened, two unthickened flagella inserting into a subapical depression in the cell. Anterior flagellum beats with a flopping motion, posterior flagellum drags behind. A cercomonad. There can be considerable variation among cells in a population. Phase contrast.

Phase contrast image showing two flagella of similar lengths inserting near the anterior pole of rhc ell. The light area posterior to the point of flagellar insertion is the nucleus. This flagellate eats bacteria - such as those around it. 

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. The cells often have an orange or brown colour because of the presence of symbiotic dinoflagellates. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. This image has been taken with polarised light so the the crystalline appearance of the arms is more evident. Phase contrast with polarised light.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. As can be seen in this micrograph, the outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The symbiotic dinoflagellates which give the acantharea an orange or brown colour can be seen here. Differential interference contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. This image shows a young cell attached to a larger cell. Phase contrast.

A light microscopic view of a living nassellarian radiolarian (Eucyrtidium acuminata) showing the reddish pigmented cytoplasm within the siliceous, conical shell.