Metamonada

Monocercomonas are small trichomonad flagellates (5-15 µm) with three anteriorly directed flagella and a recurrent one slightly adhering on its proximal part to the cell body. Well developed axostyle protruding posterioly. Parabasal body rod-, disc- or V-shaped. About 20 species occurring in the intestinal tract of vertebrates such as M. caviae from the caecum of guinea pigs (Nie 1950) or invertebrates such as termites, roaches, tipulid larvae. Unidentified species from the gut of the cockroach Parasphaeria boleiriana from Brazil (interference contrast) 

Tricercomitus (try-sir-ko-mite-us), small cells, drop shaped. The anterior seems to be the narrow end. There is obviously one very long flagellum attached to each cell, but also a rather short one. Usually in clusters. Not uncommon, from the termite Incisitermes. Phase contrast.

Hexamastix (hex-a-mas-sticks) is a monocercomonad - a member of the trichomonads. It is relatively small. It has five flagella, three can be seen in front of the cell, one passes under the cell and to the left, and one curves round to the right of the cell. The point projecting from the back of the cell is a skeletal element called an axostyle. From the termite Zootermopsis. Phase contrast.

Hexamastix (hex-a-mas-sticks) is a monocercomonad - a member of the trichomonads. It is relatively small. It has five flagella, three can be seen in front of the cell, one passes under the cell and to the left, and one curves round to the right of the cell. The point projecting from the back of the cell is a skeletal element called an axostyle. From the termite Zootermopsis. Phase contrast.

Pseudotrichomonas (sue-dough-trick-owe-moan-ass) one of the very few free-living trichomonad flagellates. With four unequal flagella arising near the anterior apex of the cell, and with an axostyle which emerges at the back of the cell. One flagellum usually forming an undulating membrane, although that is not evident here. Phase contrast.

Pseudotrichomonas (sue-dough-trick-owe-moan-ass) one of the very few free-living trichomonad flagellates. With four unequal flagella arising near the anterior apex of the cell, and with an axostyle which emerges at the back of the cell. One flagellum usually forming an undulating membrane, although that is not evident here. Phase contrast.

This free living trichomonad has three flagella projecting anteriorly and one passing backwards over the cell. This cell was not uncommon in organically rich sediments around the margins of Mono Lake. 

Pseudotrichomonas keilini Bishop, 1939. Cells plastic, especially when compressed, but usually pyriform, sometimes with a stiff posterior spike, encountered in both brackish and freshwater environments. The brackish strain is 7 to 17 microns long and the freshwater strain 8 to 12 microns long. The spike, when present, is usually less than 10 microns, but may be as long as 20 microns in compressed cells. Usually four flagella insert subapically but some cells were observed with three or five flagella. Three subequal flagella, the longest up to twice the length of the body, beat anteriorly with a co-ordinated clawing motion. The posterior flagellum is up to one and half times the length of the body, is usually attached to the cell body and beats as an undulating membrane. The length of the undulating membrane varies from less than 2 microns to almost the length of the cell. The nucleus is located in the anterior half of the cell and may be seen surrounded by granules. Food vacuoles are present in the cell. Cells may produce thin posterior threads of cytoplasm, which often adhere to the substrate. Cells swim with a jerky rotating motion.

Ditrichomonas honigbergii Farmer, 1993. Cells (4-5 microns in diameter) are variable in shape ranging from round or teardrop-sahped to nearly fusiform. In some cells the undulating membrane extends outwards producing a prominent flap along the cell s ventral / right surface. Cysts are round and 6-7 microns in diameter.

Monotrichomonas carabina Bernard et al., 1999. Cells 5 to 11 microns long, often with a fine posterior spike which may be as long as the body. Cells are bi-flagellated and normally rounded. The anterior flagellum inserts slightly subapically and is two to three times the length of the body. The posterior flagellum inserts slightly more posteriorly in a latero-posterior plane and is one to two times the length of the body. The proximal portion of the posterior flagellum attaches to the cell body as an undulating membrane, ranging from less than 2 pm long to almost the whole length of the cell. There is a small apical crest. The nucleus is located anteriorly and is surrounded by small, closely packed granules. In some cells a delicate cone of cytoskeletal material was observed running from the nuclear region to merge with the posterior spike. Food vacuoles contain bacteria. Cells swim with a jerky spiralling progression, with the anterior flagellum beating with a clawing motion and the posterior flagellum beating with wide amplitude waves. Compressed or detritus-bound cells may be very plastic, may occasionally produce fine cytoplasmic threads and may glide. During gliding, the distal portion of the flagellum forms a three-quarter loop which travels down the flagellum during cell movement, but is held stationary relative to the substrate. When the loop reaches the proximal end of the flagellum, the movement stops and the flagellum unloops. Further gliding may occur with the flagellum extending anteriorly and forming a new distal loop.

Tritrichomonas (try-try-koe-moan-ass), a trichomonas with three anterior flagella and one recurrent flagellum forming an undulating membrane. Also with an axostyle extending beyond the posterior end of the cell. Group shot, phase contrast.