Thecamoeba aesculea Kudryavtsev and Hausmann, 2009

Diagnosis: Spatulate during locomotion, sometimes slightly posteriorly tapering and almost fan shaped. Dorsal surface with 2—5 longitudinal folds and numerous irregular wrinkles, especially in the uroidal part. Single vesicular nucleus with spherical central non-homogeneous nucleolus.

Dimensions: According to Kudryavtsev and Hausmann (2009): Length of the locomotive form 70—119 µm; width 56—117.5 µm; length/width ratio 0.81—1.93; nucleus 16—22 µm in diameter; nucleolus 7.5—14.4 µm in diameter.
Ultrastructure: Glycocalyx up to 33 nm thick, consisting of a basal electron-dense layer 8—10 nm thick and a less dense outer layer about 10—15 nm thick, separated from the basal layer by an 8—10 nm thick electron-transparent space.

Ecology: Dry epiphytic mosses and bark surface of Aesculus hippocastanum

Geographical distribution: Northwestern Russia.

Remarks: Almost identical to Th. sphaeronucleolus in the size, ultrastructure of nucleus and cytoplasm, but differs from the former type strain of this species (CCAP 1583/3) in having a broader locomotive form, spatulate or fan-shaped, rather than elongated drop-shaped; also differs in the structure of the glycocalyx. Slightly resembles Th. similis, but differs from this species in the structure of the nucleus and glycocalyx.

References: Kudryavtsev and Hausmann, 2009