Pseudothecamoeba proteoides Page, 1976

Pseudothecamoeba proteoides 1-2: locomotive; 3 - cell, changing the direction of movement; 4: uroid; 5: nucleus in alive speciemen.
Scale bar 20 mkm

  • Locomotive form usually very elongate, a much flattened cylinder. The cell could be monopodial or divided into several branches like polypodial amoebians. Amoeba always have the anterior hyaline cap, if the cell is branched, every of branches bears the hyaline cap. The posterior end of the cell is narrowed, usually shrivelled-looking (Page, 1977). Dorsal surface is always wrinkled, longitudinal surface folds are usual along the posterior part of the body. Branched forms could have extended hyaline web between the branches. Length of the monopodial locomotive form 60-275 mkm (average 174 mkm), L/B 1.4 - 10.5 (average 4.0). Length of the polypodial form 95-280 mkm (average 171 mkm).
  • Afloat cell is irregular, it changes often the form and suspends soon at the substrate.
  • One oblong nucleus, 12-24 mkm in length, with numerous endosomal granules, situated beneath the nuclear membrane. Cytoplasm of the cell is highly vacuolised. Among numerous optically empty vacuoles, 2-3 contractile one could be differentiated. Cyst are not known.
  • Pseudothecamoeba proteoides Page, 1976 has filamentous cell coat; the filaments are about 80 nm in length. However, Valamo isolate (which is illustrated here) under our fixations has amorphous glicocalyx, which may be an artefact. The nucleus has inner filamentous lamina with the evidence of honeycomb-like structure.


    1. Page, F.C. 1976. An illustrated key to freshwater and soil amoebae. Inst. Terr. Ecol., FBA Sci. pub. 34.
    2. Page, F.C. 1977. The genus Thecamoeba (Protozoa, Gymnamoebia). Species distinction, locomotive morphology and protozoan prey. J. nat. Hist. 11: 25-63.
    3. page, F.C. An electron-microscopical study of Thecamoeba proteoides (Gymnamoebia), intermediate between Thecamoebidae and Amoebidae. Protistologica 14: 77-85.
    4. Page, F.C. 1988. A new key to freshwater and soil Gymnamoebia. Inst. of Feshwater Ecol., FBA.
    5. Page, F.C. 1991.Nackte Rhizopoda. Protozoenfauba, b.2: 1-170. Gustav Fisher Verlag, Stuttgart, New York.

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