Amoeba proteus
Amoeba proteus

 

Amoeba proteus (Pallas, 1766) Leidy, 1878

Diagnosis: Locomotive cells, often 220 to 760 µm in length; usually polypodial with one dominant pseudopodium, usually with dorsal and lateral folds or ridges; resting or well fed, cells irregularly rounded; floating forms wit h long radiating pseudopodia; cytoplasm granular in appearance, often with truncated bipyramidal or plate-shaped crystals; posterior uroid morulate; nucleus discoid or ovoid, sometimes with peripheral granules; nucleolar material often scattered.

Dimensions: 220-760 µm (mean 425 µm); nucleus 22-62 µm (mean 38-47 µm), discoid, often biconcave.

Ecology: freshwater and wet Sphagnum, in different types of water. Not rare.

Remarks: Though this amoeba has been described as uninucleate, I have often seen multinucleate specimens. In one sample there were amoebae with one nucleus and specimens with several nuclei (see the graph below.)

Amoeba proteus
Amoeba proteus, polytactic form 400 µm – quaking bog, Bert Bospad
Amoeba proteus, monotactic form, with two nuclei
Amoeba proteus, c. 830 µm long
Amoeba proteus
Amoeba proteus
Nucleus c. 42 µm, and the same nucleus in lateral view
Amoeba proteus
Amoeba proteus
Nucleus, lateral view
Amoeba proteus
Amoeba proteus
Nucleus, lateral view
Amoeba proteus
Amoeba proteis
Nucleus, irregular outline
Amoeba proteus
Amoeba proteus
Nucleus, lateral view, 40 µm, nucleus, lateral view, 42 µm
Amoeba proteus

 

Amoeba proteusA-C polypodial locomotion; D monopodial locomotion; E amoeba in preparation for division; bipyramidal crystal; G plate-shaped crystal; clustered crystals.
Amoeba proteus

 

floating form; B amoeba changing from floating form to Cnumber of nuclei per amoeba; E-N different shapes of nuclei: G-N lateral view.
Recent posts

Cryptodifflugia collum

Cryptodifflugia collum, after Chardez, 1971 Cryptodifflugia collum  (Chardez, 1971) Bobrov et Mazei, 2017 Difflugiella collum Chardez, 1971 Diagnosis: Shell globose, transparent, hyaline, chitinous, aperture topped

Read More »

Cryptodifflugia brevicolla

Cryptodifflugia brevicolla, after Golemansky, 1979 Cryptodifflugia brevicolla  Golemansky, 1979 Diagnosis: Shell ovate, laterally compressed, with clearly expressed chitinous collar around an aperture, neck circular in

Read More »

Cryptodifflugia bassini

Cryptodifflugia bassini, after Bobrov, 2001 Cryptodifflugia bassini  Bobrov, 2001 Diagnosis: Shell small, axially symmetrical, circular in transverse section, flattened in longitudinal section, widely elliptical. Aperture

Read More »

Cryptodifflugia apiculata

Cryptodifflugia apiculata, after Cash, 1904 Cryptodifflugia apiculata  (Cash, 1904) Page, 1966 Difflugiella apiculata  Cash, 1904 Diagnosis: Shell ovoid, not compressed laterally, chitinous, smooth, transparent, colorless,

Read More »

Cryptodifflugia angusta

Cryptodifflugia angusta, after Schönborn, 1965 Cryptodifflugia angusta  (Schönborn, 1965) Page, 1966 Difflugiella angusta  Schönborn, 1965 Diagnosis: Shell small, organic, elongated-ovate, not transparent, yellow-brown, covered with

Read More »

Cryptodifflugia angulata

Cryptodifflugia angulata, after Playfair Cryptodifflugia angulata Playfair, 1917 Diagnosis: Shell small, oval, transparent, lateral sides flattened, fundus rounded-conic, widest shell part in the middle, lateral

Read More »