world of amoeboid organisms


Stratorugosa  Melton et Tekle, 2018

Diagnosis: Flattened flabellate amoebae forming lobate subpseudopodia. During locomotion, the uroidal part of the cell is dragged forward. Contains a perinuclear MTOC, and microtubules wrap around the nucleus.
Type species: Stratorugosa tubuloviscum

Stratorugosa tubuloviscum Melton et Tekle, 2018

Diagnosis: Cells rugose and sometimes striate. Cells broadly fan-shaped, triangular, to spatulate during locomotion. A knob-shaped or elongated uroid frequently present while moving. Cells changing direction bi- to tri-lobate. Lobose or finger-like subpseudopodia sometimes present at anterior or posterior positions. Average locomotive cell sizes 89.8 µm (range from 47.5 µm to 134.9 µm) in length and 72.6 µm (range from 34.7 µm to 122.1 µm) in width. Floating cells with many radiating pseudopodia up to 60 µm in length. Cells uninucleate (average: 10.6 µm; range: 8.5 µm to 13 µm; oval to round in shape) with a single, central and spherical to oval-shaped nucleolus under the light microscope (average 6.5 µm; range: 5.5 µm to 7.9 µm); the nucleolus was never fragmented in pieces. MTs fibrillar, organized in a prominent, perinuclear MTOC always juxtaposed directly behind the nucleus, wrapped around the nucleus, and never extend throughout the whole granuloplasm or into the hyaloplasm.

Type location: Exact type locality is unknown as this sample came from a freshwater Amoeba proteus Ward’s Scientific Culture.

Differential diagnosis: While this amoeba most closely resembles a slow moving, rugose Thecamoeba, it can be differentiated from Thecamoeba species by the presence of fibrillar MTs and an MTOC, its broad fan shape and anterior and posterior lobose or finger-like subpseudopodia during locomotion, and a peculiar locomotive mechanism with two sections, front and back (uroidal), of the cells moving in a pulling and piggy back movement, respectively.

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