Microworld

world of amoeboid organisms

Menu

Family Vannellidae Bovee, 1970

Diagnosis: Amoebae have locomotive forms markedly flattened, fan-shaped, or linguiform with a prominent anterior hyaline zone without subpseudopodia. No posterior uroid. Floating form of most with radiating pseudopodia, either blunt or tapered. Nucleus of most with prominent central nucleolus, rarely with parietal lobes. Cytoplasmic crystals rare.
Glycocalyx of the only two genera studied by TEM differentiated into either pentagonal glycostyles (Vannella) or hexagonal arrangements (Platyamoeba).

Remarks: Family diagnosis emended by Page (1987) on the basis of this ultrastructural information. The present grouping of genera is based on morphological similarities at the LM level since ultrastructural details are unavailable for most.

 

1Hyaloplasm smooth2
 –Hyaloplasm with surface features3
2Hyaloplasm extends posteriorly as borderDiscamoeba
 –Hyaloplasm predominantly anteriorVannella
3Surface features faint4
 –Surface features obvious5
4Usually with faint longitudinal edge ridgesPlatyamoeba
 –Usually with faint lateral foldsClydonella
5Hyaloplasm with series of superimposed wavesUnda
 –Hyaloplasm with conoidal bossesPessonella
Recent posts

Penardochlamys arcelloides

P. arcelloides – after Penard, 1904 Penardochlamys arcelloides  (Penard, 1904) Deflandre, 1953 Diagnosis: Colorless or very slightly yellowish envelope, bag or cauldron-shaped, very thin, chitinous,

Read More »

Haplomyxa spec

Fig. 1: Main cell body of specimen A, partly hidden by debris Haplomyxa sp. Three specimens were observed in a Petri dish, along with two

Read More »

Lachmannia spec.

“Lachmannia” spec., body length 127 µm “Lachmannia” spec. I found two cells, size about 125 µm when ovoid, with an organic-walled membranous test and a

Read More »

Diplophrys spec. 7

Diplophrys spec., with three tufts of filopodia Diplophrys spec. These cells are granular, never seen before. I found them in a sample from the Bert

Read More »

Psammonobiotus spec.

I found this specimen in a sample from the Oppad, near Hilversum, 2020. It is similar to Psammonobiotus linearis, but lacks a clear spine at

Read More »

Sphenoderia compressa

Sphenoderia compressa, after Badewitz, 2002 Sphenoderia compressa Badewitz, 2002 Diagnosis: Test ovoid, oval in cross section, hyaline, covered with relatively small, oval, rather irregularly arranged

Read More »