Amoeba – Microworld

Amoeba proteus

Genus Amoeba Bory de St. Vincent, 1822

Diagnosis: locomotive cells commonly polypodial, with several tubular pseudopodia with hemispherical tips and usually hyaline caps; one pseudopodium dominant at one time, often with ectoplasmic ridges; monopodial in rapid locomotion; nucleus single, granular in most described species; resting cells irregularly rounded, floating form with long radiating pseudopodia; cytoplasm often with truncated bipyramidal crystals; posterior uroid morulate.

Ecology: Freshwater. In all kind of water types.

Key to the species:

1	Nucleus large, mean 40 µm, discoid, often biconcave	A. proteus
–	Nucleus smaller, spherical, ovoid or compressed	2
2	Nucleus compressed spherical, ovoid or lens-shaped, mean 29 µm; crystals mainly squared	A. borokensis
–	Nucleus spherical, often slightly compressed; numerous bipyramidal crystals	A. leningradensis

Amoeba proteus: A-B-C polypodial forms; D monopodium; C specimen with numerous crystals; E dividing stage (fission sphere); F bipiramidal crystal; G tile-shaped crystal; H four crystals in a row.