Cryptodifflugia Penard 1890

Introduction

Fig. 1: Pointed ectoplasmatic pseudopodia in Cryptodifflugia oviformis. © Ralf Meisterfeld

About twenty usually small species. Species with agglutinate tests can easily be mixed up with small Difflugia spp. of comparable size. The pointed ectoplasmatic pseudopodia are the differentiating character (Fig. 1).

Deflandre (1953) has placed species with circular cross-section in the genus Difflugiella and all compressed forms in Cryptodifflugia. This distinction is not made here. Following Page (1966) Difflugiella is considered to be a synonym of Cryptodifflugia.

Characteristics

The tests of Cryptodifflugia spp. have a circular or oval cross-section, either with adhering foreign particles (agglutinate) or a smooth surface.

Type species: Cryptodifflugia oviformis Penard, 1890. Here the test: smooth, clear, flask- or egg-shaped, circular in cross-section, aperture terminal. Shell wall in C. oviformis with two distinct layers, outer surface thin organic, inner layer thick from calcified material (Hedley et al., 1977).

Whether this is a common character of all Cryptodifflugia spp. has to be proven. The nucleus is always vesicular. Cyst: in test, by mucous plug.

Ecology

Cryptodifflugia species live in all freshwater habitats, mosses and soil. Due to their  small size they feed mainly on bacteria and yeasts.

Other Names for Cryptodifflugia Penard 1890

• Difflugiella

References

Grospietsch, T. 1964. Die Gattungen Cryptodifflugia und Difflugiella (Rhizopoda, Testacea). Zool. Anz., 172:243-257.

Schönborn, W. 1965a. Studien über die Gattung Difflugiella CASH (Rhizopoda, Testacea). Limnologica, 3:315-328.

Page, F. C. 1966. Cryptodifflugia operculata n. sp. (Rhizopodea: Arcellinida, Cryptodifflugiidae) and the status of the genus Cryptodifflugia. Trans. Am. Microscop. Soc., 85:506-515.

Griffin, J. L. 1972. Movement, fine structure and fusion of pseudopods of an enclosed amoeba, Difflugiella sp. J. Cell Sci., 10:563-583.

Hedley, R. H., Ogden, C. G. & Mordan, N. J. 1977. Biology and fine structure of Cryptodifflugia oviformis (Rhizopodea: Protozoa). Bull. Br. Mus. Nat. Hist. Zool., 30:313-328.