Microworld

world of amoeboid organisms

Menu
Metachaos kerrii
Metachaos spec.

Genus Metachaos Schaeffer, 1926

Diagnosis: Locomotive form usually between 75 and 500 µm in length, slender and fast moving; pseudopodia cylindrical and smooth with clear hyaline zone; cytoplasm often very granulated with bipiramidal and/or irregular crystals; nucleus discoid or spherical; uroid morulate and temporary. Distinguish from Polychaos.

Ecology: Freshwater and marine.

Type species: Metachaos discoides (Schaeffer, 1916)

Species: Metachaos spec.

The description of Schaeffer (1926) is:

“This genus, for which I propose the name Metachaos, comprises large amebas that move during locomotion by means of determinate pseudopods, that is, pseudopods that direct locomotion. The general shape of the body is oblong, resembling an antler or staghorn. The mass of the body is divided into blunt pseudopods which are cylindrical or sub-cylindrical in shape, without longitudinal folds, such as are observed in the genus Chaos. The granular endoplasm fills the entire ameba, or all but the extreme tips of the advancing pseudopods, and the granules are very evenly distributed, indicating a unified streaming of the endoplasm which involves the whole of the endoplasmic contents. A main pseudopod which leads in locomotion is distinguishable at all times. The whole ameba is therefore continually flowing through a single pseudopod, the main one, though it is always forming a number of others. Or, with a change of tense, the whole ameba will flow through the tip of its one main pseudopod. As the type species I designate the common discoides Schaeffer. The large laureata of Penard belongs in this genus.”

Metachaos kerrii
Metachaos kerrii
Metachaos spec.
Recent posts

Organic-walled species

Specimen with an optical cross-section of the peduncle (left) Organic-walled species Diagnosis: Multinucleated organic-walled monothalamous foraminifera. Test spherical to oval shaped, with a hyaline, flexible,

Read More »

Velamentofex tyrolensis

V. tyrolensis, two specimens Velamentofex tyrolensis Völcker and Clauß, 2020 April 2022, I found two specimens in a sample from the pond in Crailoo, Netherlands. I could

Read More »

Raphidiophrys spec. nov.

Raphidiophrys n. sp. Raphidiophrys n. sp. Diagnosis: Plate-scales canoe-shaped, elongated, with tapering, rounded poles, slightly curved upwardly. Light microscopically, these plate-scales show a clear rim;

Read More »

Lacogromia spec. Naardermeer

Lacogromia sp., Naardermeer, the Netherlands, 2022 (n=nucleus) Lacogromia sp. Six living specimens were found in an old sediment sample from a freshwater ditch in nature

Read More »

Sphenoderia rhombophora

S. rhombophora , after Bonnet, 1966 Sphenoderia rhombophora Bonnet, 1966 Diagnosis: Test hyaline, ellipsoidal, very slightly compressed. Fundus relatively narrow. Pseudostome largely truncated. Neck very

Read More »

Sphenoderia ovoidea

S. ovoidea , after Jung, 1942 Sphenoderia ovoidea Jung, 1942 Diagnosis: Shell with four layers of plate-scales. Distinguished from S. fissirostris by the ovoid tapering

Read More »

Sphenoderia truncata

S. truncata , after Van Oye, 1949 Sphenoderia truncata Van Oye, 1949 Diagnosis: Shell smooth and diaphanous, with usually pentagonal, sometimes hexagonal, inconspicuous plates. The

Read More »

Nebela gimlii

N. gimlii, from Singer and Lara, 2015 Nebela gimlii Singer and Lara, 2015 Diagnosis: Test wide pyriform or drop-shaped, laterally compressed, with a protruding narrow

Read More »

Sphenoderia, with granules

Overview Sphenoderia S. compressa S. fissirostris S. labiata S. lenta S. macrolepis S. minuta S. ovoidea S. rhombophora S. sphaerica S. splendida S. truncata

Read More »

Nebela overview

Nebela overview N. acolla N. aliciae N. aliciae N. barbata N. bohemica N. carinatella N. collaris N. flabellulum N. gimlii N. golemanskyi N. nebeloides N.

Read More »