Microworld

world of amoeboid organisms

Menu
Mayorella augusta
Mayorella augusta, 320 µm

Mayorella augusta Schaeffer, 1926

Diagnosis: Locomotive form triangular, with parallel dorsal folds; narrow, with anterior end sometimes divided into two branches, Y-shaped; subpseudopodia usually present; nucleus spherical, with a central somewhat granular nucleolus; cytoplasmic crystals irregular or crystals attached to spherical bodies; many vacuoles; floating form more or less symmetrically, with a number of tapering pseudopodia.

Dimensions: Schaeffer: 250-350 µm; nucleus 18 µm (n=1). My measurements: 200-320 µm, nucleus 19-27 µm, crystals up to 4 µm.

Ecology: Freshwater, in Sphagnum bogs. The amoeba feeds on both algae and protists. It can capture and digest large prey like Difflugia tuberculata, Lesquereusia spiralis and Euastrum oblongum. It can survive for months in samples.

Remarks: Schaeffers description comes from one single specimen.

Mayorella augusta
Mayorella augusta
Mayorella augusta, crystals, and nucleus, 24 µm.
Mayorella augusta crystals
Mayorella augusta crystals
Mayorella augusta, crystals attached to spherical bodies.
Mayorella augusta
Mayorella augusta, dorsal folds.
Mayorella augusta
Mayorella augusta, splitting in Y-shape.
Mayorella augusta
A: Locomotive form; B: With large diatom; C: With Lesquereusia spiralis; D: Nuclei; E: Crystals; H: amoeba with Euastrum oblongum; F: Narrow locomotive form; G: Floating form (Drawings: Ferry Siemensma, 1987
Recent posts

Euglypha bryophila

Euglypha bryophila, after Brown, 1911 (L), from Ecuador (R) Euglypha bryophila  Brown, 1911 Diagnosis: (Original description) The test is very regular in form and subject

Read More »

Vernalophrys

(A) A Scenedesmus cell (arrow) is engulfed by a trophozoite. (B) Several Scenedesmus cells adhere to the surface of a plasmodium that has numerous vacuoles

Read More »

Actinosphaeridium spec.

Actinosphaeridium spec. Diagnosis: Cell surrounded by a membranous shell, with an outer mucous layer. Filopodia with granules, sometimes branching. Cell stalked. Ecology: I found this

Read More »

Euglyphidion

Euglyphidion enigmaticum – after Bonnet, 1960 Genus Euglyphidion Bonnet, 196 Diagnosis: Shell hyaline, ovoid, pseudostome circular or slightly elliptical. Shell loosely covered with two types of

Read More »

Leptomyxa spec.

Leptomyxa sp., slowly retracting in response to the light of the microscope Leptomyxa sp. Diagnose: This is a very large amoeba which I found in

Read More »

Zivkovicia spec.

Zivkovicia spec., 200 µm long; the right image is viewed through the aperture Zivkovicia spec.  Diagnosis: Shell pyriform, circular in oral view, with a clear

Read More »