Pelomyxa Greeff, 1874 (ref. ID; 3652, 3687)

[ref. ID; 1618]
Large amoeboid organisms, ranging from 0.5 to 4 or 5 mm. in length when clavate and moving progressively; nuclei numerous less than 100 to 1000 or more; many small contractile vacuoles; refringent bodies of various dimension and number; with or without bacterial inclusions (which Penard and others consider as symbiotic); holozoic on plant or animal organisms or detritus; plasmotomy simple or multiple; in fresh water. (ref. ID; 1618)

[ref. ID; 1923]
Large amoebae with indeterminate pseudopods directing locomotion. Many nuclei; body usually enclosing symbiotic bacteria. Many species. Modern authors tend to consider as Pelomyxa the large or medium-sized amoebae showing a fixed polarity, with a single anterior pseudopod and a posterior urosphaera (= spherical zone ending the body, often provided with a tuft of very delicate pseudopods). (ref. ID; 1923)

[ref. ID; 3652]
A genus containing one species, P. palustris, a giant multinucleate amoeboid flagellate with three kinds of cytoplasmic bacteria (oxidative, glycolytic, methanogenic) often adhering to nuclei; many nonmotile flagella; many microtubules. Life cycles includes cysts. (ref. ID; 3652)


Pelomyxa carolinensis Wilson, 1900 (ref. ID; 3687) reported year? (ref. ID; 1618, 1923)
Description; Locomotion active; nuclei up to 1000 or more, circular in front view, about 20 um in diameter and ellipsoid in profile; fluid and food vacuoles, crystals, many contractile vacuoles; feeds on various protozoa and invertebrates; easily cultivated in laboratory; plasmotomy into 2-6 individuals; nuclear division simultaneous and synchronous. (ref. ID; 1618)
Without symbiotic bacteria. (ref. ID; 1923)
Measurements; Monopodal forms 1-5 mm. long; polypodal forms 1-2 mm. in diameter. (ref. ID; 1618)
Pelomyxa caulleryi (ref. ID; 3652)
Description; Pelomyxa caulleryi recognized as a recently excysted form of P. palustris. (ref. ID; 3652)
Pelomyxa illinoisensis Kudo (ref. ID; 1618, 1923)
Description; The organism resembles P. carolinensis, but much smaller in size; several hundred nuclei, spherical, 14-16 um in diameter; peripheral granules of the nuclei are large and often discoid, irregularly distributed; crystals occur abundantly in all physiological conditions; chalky white in reflected light; plasmotomy into 2-5 daughters; encystment and excystment take place freely in cultures; cysts with usually 2 membranes, a multinucleate amoeba emerges from a cyst after several weeks. (ref. ID; 1618)
Measurements; 500-1000 um in length; clavate forms seldom 1.5 mm.; cyst 250-350 in diameter. (ref. ID; 1618)
Pelomyxa laureata Penard (ref. ID; 1923)
Description; Without symbiotic bacteria. (ref. ID; 1923)
Pelomyxa palustris Greeff, 1874 (ref. ID; 3652, 3665, 3687) reported year? (ref. ID; 1618, 1923, 3693) reported author and year? (ref. ID; 3292, 3946, 4672)
Syn; Pelomyxa villosa Leidy (ref. ID; 1618)
Description; Large; sluggish, with usually one broad pseudopodium; undifferentiated cytoplasm with many nuclei and various inclusions such as fragments of plant bodies, numerous small sand particles, etc., which brings about opacity and dark coloration of body; in addition bacteria (Cladothrix pelomyxae Veley, Myxococcus pelomyxae Keller and Bacterium parapelomyxae Keller) occur in the cytoplasm which some observers consider as symbionts; cyst with 2-3 envelopes; feeds on plant and inorganic debris; polysaprobic in still stagnant water, buried in mud. (ref. ID; 1618)
Nuclei numerous. Endoplasm enclosing sand, brilliant corpuscles and bacteria simple and double rod. Habitat ooze of ponds, water with putrefying leaves, sphagnous swamps. (ref. ID; 1923)
The giant amoeba Pelomyxa palustris is a peculiar eukaryotic organism. It lacks Golgi-bodies, mitochondria, a mitotic apparatus, and any "9+2" organelle. Pelomyxa is a multinucleate herbivorous organism. (ref. ID; 3665)
Measurements; 2-3 mm. or larger in diameter. (ref. ID; 1618)