Biomyxa Leidy

Synonym Gymnophrys (Cienkowski) (ref. ID; 1618)

[ref. ID; 1618]
Body form inconstant; initial form spherical; cytoplasm colorless, finely granulated, capable of expanding and extending in any direction, with many filopodia which freely branch and anastomose; cytoplasmic movement active throughout; numerous small contractile vacuoles in body and pseudopodia; with one or more nuclei. (ref. ID; 1618)

[ref. ID; 1923]
Without shell. Pseudopodia formed from any part of the surface. (ref. ID; 1923)

[ref. ID; 5694]
Circumscription; Amoeboid protist, with stiff pseudopodia that may branch and anastomose, may produce cysts and exist as uninucleate or multinucleate amoebas. Historically classified either as a member of the ill-defined proteomyxids or the equally ill-defined athalamid granuloreticulosea. Affinities with foraminifera possible but need to be confirmed.
Ultrastructural identity: Ultrastructural studies not coupled with light microscopical studies, so there is some debate as to the identity of the organism(s) studied by electron microscopy. Mitochondria tubulocristate. With dark inclusions; microtubules in the pseudopodia are not in geometric arrays. (ref. ID; 5694)
Synapomorphy; None specified. (ref. ID; 5694)
Composition; Small and uncertain number of species. (ref. ID; 5694)
References; Anderson and Hoeffler 1979; Patterson et al. 1999 (ref. ID; 5694)

  1. Biomyxa cometa (Cienkowski) (ref. ID; 1618)
  2. Biomyxa merdaria Hollande (ref. ID; 1335, 1618)
  3. Biomyxa vagans Leidy (ref. ID; 1315, 1335, 1618, 1923, 3497, 3693)

Biomyxa cometa (Cienkowski) (ref. ID; 1618)


Subspherical or irregularly ellipsoidal; pseudopodia small in number, formed from two or more points; Cienkowski maintained that this was a moneran. (ref. ID; 1618)


Body 35-40 um, or up to 80 um or more; pseudopodia 400 um long or longer. (ref. ID; 1618)

Biomyxa merdaria Hollande (ref. ID; 1335, 1618)


Cytoplasm granular, undifferentiated; filaments, some branching; coprozoic in Hippopotamus faeces. (ref. ID; 1618)


Size variable, 10-95 um. (ref. ID; 1618)

Biomyxa vagans Leidy (ref. ID; 1315, 1335, 1618, 1923, 3497, 3693)


Main part of body, of various forms; size varies greatly; in sphagnous swamps, bog-water, etc. (ref. ID; 1618)
The body moves slowly but continuously; no distinction between ectoplasm and endoplasm observed. Pseudopodia long, branching and anastomosing, with a perceptible circulation of minute granules along the filaments. Nucleus granular. Habitat Sphagnum swamp. (ref. ID; 1923)
The protoplasmic network is usually well developed, and the plasma current is active. Therefore, the form is always changeable. A single nucleus is in the main part of the form, and many minute vacuoles are scattered in the entire form. (ref. ID; 3497)


Dimensions extremely variable; large individuals may measure 480 um between the tips of the pseudopodia. (ref. ID; 1923)
Length including pseudopodia 200 um. (ref. ID; 3497)