Tetramitus

1. Tetramitus aberdonicus (ref. ID; 7050)
2. Tetramitus descissus Perty (ref. ID; 3517)
3. Tetramitus entericus (ref. ID; 7050)
4. Tetramitus jugosus (ref. ID; 7050)
5. Tetramitus lobospinosus (ref. ID; 7050)
6. Tetramitus pyriforms Klebs, 1892 (ref. ID; 4656) reported year? (ref. ID; 1618)
7. Tetramitus pyriformis Perty (ref. ID; 3517)
8. Tetramitus rostratus Perty, 1852 (ref. ID; 4088, 7755) reported year? (ref. ID; 1618, 1796) reported author and year? (ref. ID; 4060, 7050, 7289)
9. Tetramitus salinus Entz (ref. ID; 1618)
10. Tetramitus thorntoni (ref. ID; 7050)

Tetramitus aberdonicus (ref. ID; 7050)

Descriptions

Tetramitus entericus (ref. ID; 7050)

Descriptions

Tetramitus jugosus (ref. ID; 7050)

Descriptions

Tetramitus lobospinosus (ref. ID; 7050)

Descriptions

Tetramitus pyriforms Klebs, 1892 (ref. ID; 4656) reported year? (ref. ID; 1618)

Descriptions

Measurements

Tetramitus rostratus Perty, 1852 (ref. ID; 4088, 7755) reported year? (ref. ID; 1618, 1796) reported author and year? (ref. ID; 4060, 7050, 7289)

Descriptions

• Amoeba and Cyst stage: Tetramitus amoebas have limax-type of organization, progressing by means of an ectoplasmic pseudopod lacking the usually cytoplasmic inclusions at the anterior end. The contractile vacuole generally occurs at the posterior end of the amoeba, at lest in its presystolic phase. The posterior or uroid of these limax-type amoebas is also characterized by the presence of elongate sticky filopodia, which are best observed in living cells moving over a slide substrate. Amoebas actively feeding upon a bacteria contain large numbers of food vacuoles with bacteria in various stages of digestion. Typically, bacteria being digested take the form of myelin whorls. The nucleus is a prominent feature of the amoeba. It contains a central nucleolus or endosome, giving the nucleus a vesicular appearance. In living cells, the nucleus circulates during cyclosis and/or amoeboid locomotion. Mitochondria are also present in the cytoplasm, as is endoplasmic reticulum; the later, however, is not particularly well-defined, consisting mostly of randomly scattered vesicles. No Golgi complex has been observed. Following an initial rounding of the trophic amoebas, wall material begins to appear outside of the plasma membrane. First, the developing wall is little more than irregular wisps of fuzzy material at the periphery; then, a definite wall structure appears, followed by a distinct wall made up of layers with different electron densities. The mature wall is made up of a thin ectocyst component (~70 nm thick), and a thick endocyst layer (150-200 nm thick). The source of the wall material appears to be scattered vesicles found in the cytoplasm of the rounded amoeba. Paralleling wall formation, encysting amoebas show a pronounced increase in electron density probably through a loss of fluid during encystment. The contractile vacuole remains active during the initial stages of this process. Vesicles of endoplasmic reticulum often become better defined during encystment, and are observed surrounding mitochondria. No pores develop in the Tetramitus cyst wall; when ready to excyst, the reactivated amoeba dissolves the entire wall leaving no trace of the structure. (ref. ID; 4088)
• Flagellate stage: As a flagellate, Tetramitus has a rigid pellicle and is shaped like a toy spinning top. As its generic name implies, four flagella arise from its anterior surface. A collar or rim circumscribes the anterior end of the body. The collar is drawn out on the right (the organism's right) into a protruding rostrum; on the organism's left, the collar descends diagonally and then curves up again to produce the ventral groove, a depression on the anterior ventral surface. The kinetosomes of the flagella are located on the right lateral surface of the collar. Hollande (1942) has described the flagella as arising from two dimorphic blepharoplasts, one shaped like a granule and the other like a rod. In squashed fresh and osmium-fixed material, the rod-shaped blepharoplast can be resolved into a row of three kinetosomes. Each of the four flagella arises from a separate kinetosomes. One flagellum arises a little to the right of the other, but there is no special orientation to the flagellar beat which could be related to the position of the kinetosomes. Radiating basally from the row of three kinetosomes are long, slender, refringent fibers, the multiple rhizoplasts. These extend ventro-posteriorly or dorsally or laterally. A contractile vacuole, arising from confluent small vacuoles, is generally situated anterior and on the left side of the organisms. No evidence is found of a permanent pore through which vacuolar contents are expelled. The nucleus, as in the amoeba, is a round or slightly elongate vesicle located in the upper third of the body. The nucleolus appears to diminish with age of the culture, and an increase in nucleolar abnormalities (e.g. double nuclei) accompanies aging. Light microscopy reveals a structure that is apparently constant in Tetramitus, but difficult to see in actively growing cultures. It is a funnel-shaped extension of the ventral groove which projects laterally or dorsally into the interior of the body. Cells stained with nigrosin indicate that the extension is restricted to the middle third of the body. It appears to function as a gullet since, in this sections, bacteria have been seen in the lumen of this structure. The posterior third other body is drawn out into a long, cone-shaped tail. In living cells, this region is densely packed with food vacuoles and refractile granules. (ref. ID; 4088)

Comments

Tetramitus salinus Entz (ref. ID; 1618)

Descriptions

Measurements

Tetramitus thorntoni (ref. ID; 7050)

Descriptions