Microworld

world of amoeboid organisms

Menu
Acanthocystis penardi
Acanthocystis penardi, body 130 µm, with attached empty Arcella test.

 

Acanthocystis penardi  Wailes, 1925

Diagnosis: Periplast 9-125 μm, average 30 μm. Radial spine scales long, 6-25 μm, sometimes distinctly separated into long and short spines, which differ only in length. Long needles average three-thirds of the envelope diameter. Shaft 0.25-0.5 μm thick, straight, hollow and cylindrical, slightly enlarged and provided with 8-14 magical teeth. Basal disc 1.0-3.5 μm in diameter, with central shank. Tangential scales 2.2-3.6 μm x 3.1-5.7 μm, oval, often with concave sides, without distinct structure, slightly thickened in the centre, sometimes with slightly thickened margin. Cyste with long, narrow scales, which have a longitudinal bead in the middle. Axopodia usually relatively short, rarely longer than twice the body diameter. Nucleus shape-changing and highly eccentric. Constantly moving, rarely resting. Large individuals sometimes with zoochlorella. The habitus form can be very different. In their typical form, determination by light microscope is not difficult.

Ecology: Widespread in various water types: moors, ponds, ditches and lakes; both in dystrophic and eutrophic waters; between aquatic plants and on sediments. Up to 35 m depth in Lake Geneva (Penard, 1904). Europe, Canada, Chile, Malaysia.

Acanthocystis penardi
Drawing Ferry Siemensma
Acanthocystis penardi
Recent posts

Velamentofex

Velamentofex tyrolensis Family Velamentofexidae Völcker and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to pyriform, usually surrounded by a broad layer of mucus-like

Read More »

Claparedellus lachmannii

Claparedellus lachmannii, common shape (Riedensee) Claparedellus lachmannii  Khanipour Roshan and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to elongated pyriform or irregularly shaped, with a

Read More »

Claparedellus

Claparedellus lachmannii Genus Claparedellus Khanipour Roshan and Clauß, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test spherical to elongated pyriform or irregularly shaped, with a hyaline, flexible,

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 »

Edaphoallogromiidae

Edaphoallogromia australica Family Edaphoallogromiidae Siemensma, Holzmann, Apothéloz-Perret-Gentil, Clauß, Voelcker, Bettighofer, Khanipour Roshan, Walden, Dumack and Pawlowski, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera with a spherical

Read More »

Lachmanni spec.

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

Read More »