Microworld

world of amoeboid organisms

Menu
Vannella simplex
Vannella simplex
Vannella simplex

Genus Vannella Bovee, 1965

Diagnosis: Locomotive form commonly flabellate or fan-shaped, often semi-circular with broad hyaline margin around sides, or in some spatulate with long tail; flattened anterior hyaloplasm occupying up to half the length of the cell; breadth usually greater than length making the cell commonly fan-shaped; no longitudinal wrinkles; floating form of all freshwater species and most marine species with pseudopodia tapering markedly, sometimes pointed, sometimes tightly helical; nucleus with central nucleolus; cysts have not been found in any species classified with certainty in this genus.
Ultrastructure: cell coat of examined species has pentagonal glycostyles slightly more than 100 nm tall.

Remarks: Common in both fresh water and marine habitats. The species problem seems difficult in Vannella. Given its commonness, it may not be possible to assign all isolates to named species. Vannella is hard to distinguish with certainty from Platyamoeba (Page, 1988). and the recently described Ripella.

 
Recent posts

Arcella marginata

Arcella marginata, after Deflandre, 1929 Arcella marginata Daday, 1905 Diagnosis: Shell roughly hemispherical, rather overhanging, with a flattened, smooth edge. In dorsal view showing a

Read More »

Arcella lobostoma

Arcella lobostoma, after Deflandre, 1929 Arcella lobostoma Deflandre, 1929 Diagnosis: Shell hemispherical. In ventral view, irregular circular outline, often a little elliptical; pseudostome irregularly lobed:

Read More »

Pelomyxa video

Pelomyxa palustris Pelomyxa palustris, found below decaying leaves in the hollow of a beech Pelomyxa palustris, found below decaying leaves in the hollow of a

Read More »

Hoogenraadia galeata

H. galeata – from Stepanek, 1963 Hoogenraadia galeata  (Stepanek, 1963) n. comb. Gillardella galeata Stepanek, 1963 Diagnosis: Shell somewhat similar to the shell of Corythion dubium

Read More »

Arcella grospietschi

Arcella grospietschi, after Stepanek, 1963 Arcella grospietschi  Stepanek, 1963 Diagnosis: Shell disc-shaped, yellow-brown, in ventral view with a undulated border, with seven large and seven smaller

Read More »

Arcella oyei

Arcella oyei, after Stepanek, 1963 Arcella oyei  Stepanek, 1963 Diagnosis: In dorsal view, the shell is circular, with 10 apparent broken lobes on the surface. In

Read More »