Microworld

world of amoeboid organisms

Menu
Netzelia oviformis
Netzelia oviformis
Netzelia oviformis, 76 µm

Netzelia oviformis (Cash, 1909) Ogden, 1979

Diagnosis: Shell elongate ovoid, usually yellow or brown in color; symmetrical and smooth with a broadly-rounded dorsal part; sides curving downwards to the rather narrow and usually tri- or four-lobed mouth which is furnished with an thick wavy lip or collar; shell constructed of flat mineral grains, fragments of diatom frustules and secreted siliceous idiosomes in assorted mixtures to give a smooth surface. Organic cement building units seen as part of general shell matrix, each unit having distinct pores on both inner and outer faces. Single, vesicular nucleus with central nucleolus, one contractile vacuole, cytoplasm not filling shell cavity; pseudopodia numerous simply branched.

Dimensions: Cash 110 µm long and 80 µm broad; other workers: 65-95 µm. My dimensions: 66-85 µm.

Ecology: Between water plants and in mosses like Sphagnum; usually rare, but sometimes locally abundant.

Remarks: Usually the aperture is 3-5 lobed, but a two-lobed specimen has been reported by Bruce Taylor (pers. comm.). The aperture is surrounded by a thick layer of organic cement which obscures the necklace of small particles. This covering was described as “an expanded wavy collar of thin chitinous substance” by Cash (1905) and clearly figured by Ogden (1980).This rare species is easy to identify. I have seen it in material from the Kromme Rade in Kortenhoef, the Netherlands. In September 2012 I found a very rich population in an isolated forest pond in Baarn. The population occurred in debris on water plants and all specimens had a four-lobed aperture. Within this population specimens with slender and broad ovoid shells occurred.

Netzelia oviformis
N. oviformis, 70 µm
Netzelia oviformis
Netzelia oviformis
Original drawing of N. oviformis in Cash, Wailes & Hopkinson.
Netzelia oviformis
Netzelia oviformis
Netzelia oviformis, four and five lobed aperture
Netzelia oviformis
Netzelia oviformis
N. oviformis, from Haaksbergen, Netherlands
Netzelia wailesi
Netzelia wailesi
N. oviformis, 85 µm, forest pond, Baarn; right: detail of a collar.
Netzelia oviformis
Netzelia oviformis, 85 µm, brownish red – forest pond, Baarn
Netzelia oviformis
Netzelia oviformis
N. oviformis, from Ogden, 1980
Recent posts

Foraminifer drome

Unknown species, collected from the river Drôme, France, 2021 Unknown species September 2021, I found three specimens of an agglutinated foraminifer in a sample collected

Read More »

Cyclopyxis spec

Cyclopyxis spec., 168 µm Cyclopyxis spec. Diagnosis: Shell circular in ventral and dorsal view, more or less hemispherical in lateral view (height/diameter ≈ 0.5); lateral

Read More »

Difflugia fallax

Difflugia fallax, from Penard, 1902 Difflugia fallax Penard, 1890 Diagnosis: Shell hyaline or yellowish-greenish, black at low magnification, round in cross section, formed of a

Read More »

Zivkovicia compressoidea

Z. compressoidea, a-b after Chardez, 1958; c after Jung, 1942 Zivkovicia compressoidea  (Jung, 1942) new.comb. Basionym: Pontigulasia compressoidea Jung, 1942 Diagnosis: Shell ovoid and compressed,

Read More »

Zivkovicia flexa

Z. flexa, from Cash and Hopkinson, 1909 Zivkovicia flexa  (Cash and Hopkinson, 1909) Ogden, 1983 Basionym: Pontigulasia compressa var. flexa  Cash and Hopkinson, 1909 Diagnosis:

Read More »

Lagenodifflugia epiouxi

L. epiouxi, after Chardez, 1984 3 Lagenodifflugia epiouxi (Chardez, 1983) new comb. Basionym: Pontigulasia epiouxi Chardez, 1983 Diagnosis: Shell elongate, circular in cross-section or very

Read More »

Centropyxis lapponica

Centropyxis lapponica, after Grospietsch, 1954 Centropyxis lapponica  Grospietsch, 1954 Diagnosis: Shell nearly circular in circumference, without spines. Aperture clear square with rounded corners. Shell viewed

Read More »

Chaos spec. 6

Chaos spec., Crailoo, 2021 Chaos spec. This specimen was found in a samples from Crailoo, Netherlands. It was remarkable because of the absence of crystals.

Read More »

Bullinularia maxima

Bullinularia maxima – from Bobrov and Mazei, 2020 Bullinularia maxima Bobrov et Mazei, 2020 Diagnosis: Shell brown, opaque, elliptical in ventral view; ventral surface is

Read More »