world of amoeboid organisms

Cryptodifflugia oviformis
Cryptodifflugia oviformis
Cryptodifflugia oviformis – 26 and 25 µm long

Genus Cryptodifflugia Penard, 1890

Diagnosis: Shell oval, egg-shaped, pyriform with a short neck, circular or oval cross-section, with adhering foreign particles or smooth surface, colorless, yellow or brown, composed of an outer proteinaceous material usually lined, aperture terminal, circular or oval. Pseudopods are in the form of ectoplasmic anastomosing reticulolobopods.
Type species: Cryptodifflugia oviformis Penard, 1890.

Ecology: Fresh water, soil and mosses.

Key to the species

1Shell distinctly compressed laterally2
Shell not or slightly compressed laterally7
2Oval aperture3
Circular apertureC. compressa angustioris
3Shell length 45–63 µmC. angustastoma
Shell length 32–45 µmC. paludosa
Shell is smaller than 25 µm4
4Shell width > lengthC. compressa australis
Shell width < length5
5Shell lanceolateC. lanceolata
Shell pyriformC. brevicolla
Shell ovate6
6Thick organic lip around the apertureC. compressa
No lip around the aperture C. compressa ovata
7Shell surface crenulate8
Shell surface not crenulate10
8Shell shape ovoid9
Shell shape globose or subgloboseC. crenulata globosa
9Shell length < 20 µmC. crenulata
Shell length > 23 µmC. splendida
10Shell pyriform with prominent neck; surface covered by rare sand grains11
Shell ovoid or globular, without prominent neck13
11Shell surface covered by rare sand grains12
Shell surface smoothC. collum
12Shell length 16–26 µm; aperture 4–5 µm; neck  1/3 of shell lengthC. sacculus
Shell length 27–30 µm; aperture 10–13 µm; neck  1/4 of shell lengthC. sacculus sakotschawi
13Lateral sides conical (angular)C. angulata
Lateral sides rounded14
14Aperture diameter equal to shell width15
Aperture diameter considerably smaller than shell width16
15Shell width equal to shell lengthC. pusilla
Shell width considerably smaller than shell lengthC. pusilla conica
16Shell length > 40 µm27
Shell length < 40 µm17
17Shell length 8–12 µm18
Shell length higher20
18Shell length higher than shell widthC. minuta
Shell length considerably smaller than shell width19
19Shell surface covered by scarce sand grainsC. patinata
Shell surface smoothC. bassini
20Shell surface covered by scarce sand grains25
Shell surface smooth21
21Aperture large, its diameter about 1/3–1/4 of maximal shell width23
Aperture small, its diameter about 1/6–1/8 of maximal shell width22
22Aperture diameter 1.5–2.5 µmC. leachi
Aperture diameter 3.5–4.5 µmC. vulgaris
23Shell ovoid24
Shell pyriformC. crenulata glabra
24Shell colorlessC. oviformis
Shell yellowish-brown, ovalC. oviformis fusca
25Shell subsphaerical, width/length ratio > 0.8C. horrida
Shell elongated, width/length ratio < 0.726
26Shell length 24–27 µmC. voigti
Shell length 20–24 µmC. psammophila
Shell length 17–21 µmC. angusta
27Shell length 40 µm, broadest width at the middle of the shellC. apiculata
Shell length 55 µm, broadest width at the upper third of the shellC. valida

After Bobrov and Mazei, 2017

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