Microworld

world of amoeboid organisms

Menu
Menu
Difflugia elegans angustata
Difflugia elegans var. angustata, Gaasterland, 2019

Difflugia elegans var. angustata  (Penard, 1890) Deflandre, 1926

Diagnosis: The variety differs from the type by its more slender pace and its smaller size and the commonly curved spine. The width is proportionately smaller, the mouth remaining substantially similar; nucleus with a limited number of nucleoli; nucleoli with small lacunae.

Dimensions: Deflandre (1926): Length (ex. icon.) 70 µm; Length/Width ratio 2.52 to 2.71. Ogden (1984): Length 95–118 μm, Width 44–51 μm, aperture diameter 24–27 μm (n=4). My measurements: Length 61-96 µm (n=20); nuclear diameter 14.3 µm (n=1).

Remarks: I found this variety together with a population of of the typical D. elegans in Gaasterland, 2019. The distinction between both groups was clear. Maybe this is not a variety but a separate species. According to Ogden (1984), the only features that differentiate this variety from the type are the elongate shape of the shell and the absence of a constriction near the aperture.

Ecology and distribution: Freshwater. Venezuela (Deflandre, 1926), Serbia (Ogden, 1984), Netherlands.

Original description (Deflandre, 1926): “Malgré de notables variations de la forme chez D. elegans je crois néanmoins bon de distinguer comme variété une série d’individus que j’ai trouvés plusieurs fois, suffisamment semblables entre eux pour admettre une certaine fixité: var. angustata var. nov. (Penard, 1902 page 247, fig. 11). La variété diffère du type par son allure plus élancée. La largeur est proportionnellement plus faible, la bouche restant sensiblement semblable. Le rapport de la longueur à la largeur qui, dans les formes typiques varie entre 1,54 et 1,77, atteint ici de 2,52 à 2,71 (fig. 10)
Distribution. Mare Mangas Goberas, Venezuela.” (Translated: Despite notable variations in form in D. elegans, I nevertheless believe it is good to distinguish as a variety a series of individuals that I have found several times, sufficiently similar to each other to admit a certain fixity: var. angustata var. nov.. The variety differs from the type by its more slender appearance. The width is proportionately smaller, the mouth remaining substantially similar. The ratio of the length to the width which, in typical forms varies between 1.54 and 1.77, reaches here from 2.52 to 2.71 (fig. 10)).

Difflugia elegans angustata
D. elegans var. angustata, a after Penard, 1902; b after Deflandre, 1926; c after Ogden, 1984
Difflugia elegans - Ferry Siemensma
Difflugia elegans, all shells descended from one specimen which multiplied in a moist-chamber-mount, 79-86 µm long – Naardermeer, 2016.
Difflugia elegans - Ferry Siemensma
Difflugia elegans var. angustata, all shells from the same culture as above, 83-96 µm long – Naardermeer, the Netherlands
Difflugia elegans angustata
Difflugia elegans var. angustata, Gaasterland
Difflugia elegans angustata
D. elegans var. angustata, nucleus
Difflugia bicornis
D. elegans var. angustata; plot of a number of measurements of shells from the Gaasterland location, July 2019. It might be possible that D. bicornis falls within the variation of D. elegans, though the latter has smaller tests, but D. angustata seems a distinct species and not just a variety.
Recent posts

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

Zivkovicia 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 »

Bullinularia macroporum

Bullinularia macroporum – from Bobrov and Mazei, 2020 Bullinularia macroporum Bobrov et Mazei, 2020 Diagnosis: Shell yellow-brownish, transparent, circular in ventral view; ventral surface is

Read More »

Nebela golemanskyi

N. golemanskyi, after Todorov, 2010 Nebela golemanskyi Todorov, 2010 Diagnosis: Shell large, colourless and pyriform, with a distinct short neck about one fourth of the

Read More »

Nebela nebeloides

N. nebeloides, after Gauthier-Lièvre and Thomas, 1958 Nebela nebeloides (Gauthier-Lièvre and Thomas, 1958) Todorov et al., 2010 Basionym: Difflugia nebeloides Gauthier-Lièvre and Thomas, 1958 Diagnosis:

Read More »