Microworld

world of amoeboid organisms

Menu
Trichamoeba sinuosa
Trichamoeba sinuosa, 170 µm

Genus Trichamoeba Fromentel, 1874

Diagnosis: active locomotion form limax-like, regularly monopodial, slender to broad and thick, most between 75 and 250 µm in length; bulbous uroid or with short villi, some with fine filaments; floating form, where known, with radiating blunt pseudopodia; nucleus usually granular, with nucleoli arranged peripherally; commonly uninucleate; cytoplasm often with bipyramidal crystals.

Type species: Trichamoeba hirta (Fromentel, 1974)

Ecology: Freshwater and marine.

Remarks: These are the uninucleate, regularly monopodial, free-living Amoebidae. Other members of the family may occasionally become monopodial in rapid locomotion or under special conditions, and some such monopodial forms have pronounced uroids. It was to such a normally polypodial amoeba that Wallich gave the name Amoeba villosa. But Trichamoeba is always monopodial during steady locomotion in one direction, putting out another pseudopodium only for a marked change in direction (Page, 1988).
Trichamoeba may be confused with the more common Saccamoeba. With the light microscope these are most easily distinguished by the nucleus, which is ovular in all known species of Trichamoeba and has a single central nucleolus in known species of Saccamoeba. The floating form of most species of Trichamoeba has the pseudopodia characteristic of such forms in the Amoebidae, while that of Saccamoeba is irregularly rounded without pseudopodia (Page, 1988).

References: Bovee (1972); Schaeffer (1926); Siemensma & Page (1986).

Key to the species:

1 Locomotive form usually > 150 µm 2
Locomotive form usually < 150 µm T. cloaca
2 Amoeba slender, with a zigzag movement T. sinuosa
Amoeba broad elliptical or ovoid T. myakka
Recent posts

Amoeba proteus var.

Amoeba proteus var. Amoeba proteus var.  Diagnosis: This variety differs from the type by its oval nucleus. Dimensions: 250-400 µm (n=2); nucleus 34 x 29

Read More »

Reticulomyxa hannae

R. hannae, plasmodium – photomicrograph Steffen Clauß Reticulomyxa hannae Völcker and Clauß, 2020 Diagnosis: Trophozoites surrounded by a very thin mucous envelope, with slowly moving plasmodia, variable

Read More »

Velamentofex

Velamentofex tyrolensis (photomicrograph Steffen Clauß) Family Velamentofexidae Völcker and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to pyriform, usually surrounded by a broad

Read More »

Claparedellus lachmannii

Claparedellus lachmannii, common shape (Riedensee) Claparedellus lachmannii  Khanipour Roshan and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to elongated pyriform or irregularly shaped, with a

Read More »

Claparedellus

Claparedellus lachmannii Genus Claparedellus Khanipour Roshan and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to elongated pyriform or irregularly shaped, with a hyaline, flexible,

Read More »

Velamentofex tyrolensis

V. tyrolensis (photomicrograph Steffen Clauß) Velamentofex tyrolensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 98-125 μm, with reticulopodia up to 300 μm long, with a hyaline,

Read More »