The Vannellidae are a family of
Amoebozoa, which are found in soil, fresh- and salt water.
The most common genus is ''Vannella''.
Description
''Vannellidae'' tend to be flattened and fan-shaped during motion, although some are long and narrow, and have a prominent clear margin at the
anterior.
In most amoebae, the
endoplasm
Endoplasm generally refers to the inner (often granulated), dense part of a cell's cytoplasm. This is opposed to the ectoplasm which is the outer (non-granulated) layer of the cytoplasm, which is typically watery and immediately adjacent to the ...
glides forward through the center of the cell, but vannellids undergo a sort of rolling motion with the outer membrane sliding around like a
tank tread. These amoebae are usually 10-40 μm in size, but some are smaller or larger.
''Vannellidae'' are surrounded by an outer covering called the
glycocalyx
The glycocalyx, also known as the pericellular matrix, is a glycoprotein and glycolipid covering that surrounds the cell membranes of bacteria, epithelial cells, and other cells. In 1970, Martinez-Palomo discovered the cell coating in animal c ...
, which is generally 10-20 nm across, though the thickness varies among species. In some species, a layer of hair-like filaments called
glycostyles protrudes from the glycocalyx.
Taxonomy
Molecular phylogenies include them in the class
Flabellinia
The Flabellinia are a subclass of Amoebozoa. During locomotion the cells are flattened and have a clear layer called ''hyaloplasm'' along the front margin. Some form slender subpseudopodia projecting outward from the hyaloplasm, but the cell ma ...
as a
sister group to the others, which have subpseudopodia.
References
Amoebozoa families
Discosea
{{Amoebozoa-stub