Lobose Amoebae

Percolomonas descissus (Perty, 1852) Larsen and Patterson, 1990. Cells are ovoid to pyriform and about 9 to 15 microns long with a big ventral groove, which extends from the anterior end to half or three quarters the way down the cell. There are four flagella, which insert subapically and are directed ventrally and posteriorly. Three flagella are similar in length and one long flagellum is about 1.5 - 2 times the length of the cell. All flagella usually beat together and close to the groove. The longest flagellum appears to be acronematic. The nucleus is situated behind the apex of the cell. The cells swim by rotating movement and may attach to the substrate by the longest flagellum. The cells have typically with many food vacuoles. Cytoplasmic strands are seen in the posterior end of the cell. Observed more usually from anaerobic sources.

Stachyamoeba (stack-ee-a-me-ba) is a free-living amoeba, usually flattended, expanded anterior margin with broad hyaline zone. With filaments arising from the uroid. At one time treated as a gruberellid and probably related to the acrasids, it can be seen to have a flagellated stage with two flagella which indicates that it is a fairly conventional heteroloboseid. Phase contrast.

Stachyamoeba (stack-ee-a-me-ba) is a free-living amoeba, usually flattended, expanded anterior margin with broad hyaline zone. With filaments arising from the uroid. At one time treated as a gruberellid and probably related to the acrasids, it can be seen to have a flagellated stage with two flagella which indicates that it is a fairly conventional heteroloboseid. Cysts have an irregular wall. Differential interference contrast.

Stachyamoeba (stack-ee-a-me-ba) is a free-living amoeba, usually flattended, expanded anterior margin with broad hyaline zone. With filaments arising from the uroid. At one time treated as a gruberellid and probably related to the acrasids, it can be seen to have a flagellated stage with two flagella which indicates that it is a fairly conventional heteroloboseid. Phase contrast.

Pleurostomum flabellatum Ruinen, 1938. Cell 11-14 microns long, spindle-shaped and round in transverse section with two parallel flagella inserting apically. The flagella are 0.5-1.5 times body length. They are often, but not always, the same length. The flagella were usually observed stuck to the coverslip or slide. When free the flagella beat homodynamically. Subapically there is a wide and deep opening or groove that runs half to three quarters the way down the body in a half spiral and usually ends in close association with a food vacuole. The body was not observed to bend or flex except in one individual where the posterior third of the cell was stuck to the coverslip.

Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus of uncertain affinities and include a small handful of species. Cells are dorso-ventrally flattened, with a wide anterior mouth which may or may not have some barbs. It moves by using flagella which are laid out in longitudinal rows. For a long time erroneously considered to be a primitive ciliate (distinguished from real ciliates because it does not have macronuclei and micronuclei). This encysting cell can be seen to have several conventional nuclei with central nuceoli. Eats diatoms and detritus. Phase contrast.

Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus of uncertain affinities and include a small handful of species. Cells are dorso-ventrally flattened, with a wide anterior mouth which may or may not have some barbs. It moves by using flagella which are laid out in longitudinal rows. For a long time erroneously considered to be a primitive ciliate (distinguished from real ciliates because it does not have macronuclei and micronuclei). Eats diatoms and detritus. Phase contrast.

Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus of uncertain affinities and include a small handful of species. Cells are dorso-ventrally flattened, with a wide anterior mouth which may or may not have some barbs. It moves by using flagella which are laid out in longitudinal rows. For a long time erroneously considered to be a primitive ciliate (distinguished from real ciliates because it does not have macronuclei and micronuclei). Eats diatoms and detritus. Phase contrast.

Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus of uncertain affinities and include a small handful of species. Cells are dorso-ventrally flattened, with a wide anterior mouth which may or may not have some barbs. It moves by using flagella which are laid out in longitudinal rows. This organism was for a long time through to be a ciliate - because it looks like a ciliate. But examination of the cellular organization revealed that it s internal architecture was very different to that of ciliates - and they don t have two kinds of nuclei - like ciliates. Like many ciliates, it has flagella in rows or kineties. The anterior margin is the mouth, and the eat bacteria. Differential interference contrast.

Stephanopogon (steff-ann-owe-poe-gone) apogon Borror, 1965. Cells are about 18 - 32 microns long with several lows of kineties and dorso-ventrally flattened. The cells have a mouth located at the anterior end of a flattened neck of the cell. The cells crawl or swim with flagella. Rarely observed.

Stephanopogon apogon Borror, 1965. Cells are about 18 - 32 microns long with several lows of kineties and dorso-ventrally flattened. The cells have a mouth located at the anterior end of a flattened neck of the cell. The cells crawl or swim with flagella. Rarely observed.

This drawing presents the author’s understanding of the ultrastructural organization of the mouth region of Stephanopogon apogon. The opening of the mouth is to the left, and is surrounded by lips. These are strengthened inside by a quoit of fibrous material. Rods of microtubules support the region leading into the body, and there are many small gland-like folds of the membrane leading into this region. The body is supported by flat ribbons of microtubules. There are flagella on the lower surface of the cell and these are held in place by crown-like arrays of microtubules, and are interconnected by flat plates of material.

Portrait (dorsal surface) of the colorless benthic marine protist, Stephanopogon apogon (Borror, 1965). The closest relatives of Stephanopogon are currently uncertain. Once thought to be a ciliate, electron microscopic studies of S. apogon revealed absence of ciliate characteristics such as pellicular alveoli, infraciliature (e.g. kinetodesmal fibrils, postciliary microtubules and transverse microtubules) and nuclear dualism. S. apogon is elongate and moderately dorsoventrally flattened. The cell is curved slightly to the right. The posterior is round and the anterior end obliquely truncate. There are approximately 6-8 longitudinal files of smooth flagella limited to the ventral surface. The anterior apical cytostome is slit-like and bordered by a slightly raised lip. There are 2-16 homokaryotic nuclei (not seen here). Division occurs while encysted (palintomy). Collected from a commercial saltwater aquarium in Boise, Idaho September 2004. DIC.

Portrait (ventral surface) of the colorless benthic marine protist, Stephanopogon apogon (Borror, 1965). The phylogenetic affinitiees of Stephanopogon are uncertain. Once thought to be a ciliate, electron microscopic studies of S. apogon revealed absence of ciliate characteristics such as pellicular alveoli, infraciliature (e.g. kinetodesmal fibrils, postciliary microtubules and transverse microtubules) and nuclear dualism. S. apogon is elongate and moderately dorsoventrally flattened. The cell is curved slightly to the right. The posterior is round and the anterior end obliquely truncate. There are approximately 6-8 longitudinal files of smooth flagella limited to the ventral surface. The anterior apical cytostome is slit-like and bordered by a slightly raised lip. There are 2-16 homokaryotic nuclei (not seen here). Division occurs while encysted (palintomy). Collected from a commercial saltwater aquarium in Boise, Idaho September 2004. DIC.  

Portrait of the colorless benthic marine protist, Stephanopogon apogon (Borror, 1965)attempting (ambitiously) to ingest a large diatom. The phylogenetic affinities of Stephanopogon are uncertain. Once thought to be a ciliate, electron microscopic studies of S. apogon revealed absence of ciliate characteristics such as pellicular alveoli, infraciliature (e.g. kinetodesmal fibrils, postciliary microtubules and transverse microtubules) and nuclear dualism. S. apogon is elongate and moderately dorsoventrally flattened. The cell is curved slightly to the right. The posterior is round and the anterior end obliquely truncate. There are approximately 6-8 longitudinal files of smooth flagella limited to the ventral surface. The anterior apical cytostome is slit-like and bordered by a slightly raised lip. There are 2-16 homokaryotic nuclei (not seen here). Division occurs while encysted (palintomy). Collected from a commercial saltwater aquarium in Boise, Idaho September 2004. DIC. 

Portrait ((dorsal surface) of the colorless benthic marine protist, Stephanopogon apogon (Borror, 1965). The taxonomic position of Stephanopogon is uncertain. Once thought to be a ciliate, electron microscopic studies of S. apogon revealed absence of ciliate characteristics such as pellicular alveoli, infraciliature (e.g. kinetodesmal fibrils, postciliary microtubules and transverse microtubules) and nuclear dualism. S. apogon is elongate and moderately dorsoventrally flattened. The cell is curved slightly to the right. The posterior is round and the anterior end obliquely truncate. There are approximately 6-8 longitudinal files of smooth flagellae limited to the ventral surface. The anterior apical cytostome is slit-like and bordered by a slightly raised lip (visible here). There are 2-16 homokaryotic nuclei (not seen here).A contractile vacuole is absent. Division occurs while encysted (palintomy). Collected from a commercial saltwater aquarium in Boise, Idaho September 2004. DIC.

Portrait (ventral surface) of the colorless benthic marine protist, Stephanopogon apogon (Borror, 1965). The phylogenetic affinities of Stephanopogon are uncertain. Once thought to be a ciliate, electron microscopic studies of S. apogon revealed absence of ciliate characteristics such as pellicular alveoli, infraciliature (e.g. kinetodesmal fibrils, postciliary microtubules and transverse microtubules) and nuclear dualism. S. apogon is elongate and moderately dorsoventrally flattened. The cell is curved slightly to the right. The posterior is round and the anterior end obliquely truncate. There are approximately 6-8 longitudinal rows of smooth flagella limited to the ventral surface. The anterior apical cytostome is slit-like and bordered by a slightly raised lip. There are 2-16 homokaryotic nuclei (not seen here). Division occurs while encysted (palintomy). Collected from a commercial saltwater aquarium in Boise, Idaho September 2004. DIC.

SCanning EM showing the dorsal face of the cell with ciliary lines and the anterior mouth bordered with lips.

Cell stained by protargol showing the kineties of cilia of one face of the cell and the anterior mouth.

Scanning EM showing the ventral face of the cell with ciliary lines and the anterior mouth bordered with lips.

Adjacent thin sections thropugh a kinety on the ventral surface of this 'flagellate'. Ventral is to the top of the image.

ATCC culture 50096. Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus that includes a small handful of species. This taxon has recently been placed in Heterolobosea.

Stephanopogon apogon (steff-anne-owe-poe-gone) is a marine genus that was recently placed in the Heterolobosea. ATCC culture 50096.