Lesquereusia Schlumberger 1845

Introduction

This genus was erected by Schlumberger (1845) and obviously named after the swiss naturalist Lesquereux. By lapsus it was first published as Lecqereusia. The currently used spelling was introduced by Hopkinson (in Cash & Hopkinson, 1909)!

Characteristics

The tests are characterised by an asymmetrical neck which is more or less attached to the body. Depending on the species the agglutinate test is either composed of endogenous siliceous rods or other collected mineral particles or a mixture of both.  The idiosomes or xenosomes are always fixed by a structured mesh-like cement (Fig. 1). All Lesqereusia spp. have an ovular nucleus.  16 species have been described, type species: Lesquereusia spiralis (Ehrenberg, 1840). Species differ mainly in shape of the siliceous rods, the amount of mineral particles used and the orientation of the neck.  Stump (1959) and Freeman (1974) have studied the mitosis in cultured material and the cytology (TEM and cytochemistry) has been studied by Harrison et al. (1975, 1976).

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Fig. 1: Structured cement of Lesquereusia modesta . © Ralf Meisterfeld

Habitat: Peryphyton, aquatic mosses or sediments. Feeding: herbivore (diatoms, green algae).

Other Names for Lesquereusia Schlumberger 1845

• Lecqereusia

References

Thomas, R. & Gauthier-Lièvre, L. 1959a. Le genre Lesque¬reusia Schlumberger 1845 (Rhizopodes testacés). Bull. Soc. Hist. Nat. Afr. Nord, 50:34-83 , Pl. I, II.

Thomas, R. & Gauthier-Lièvre, L. 1961. Addenda et corrigenda le genre Lesquereusia Schlumberger. Bull. Soc. Hist. Nat. Afr. Nord, 52:162-163.

Ogden, C. G. & Hedley, R. H. 1980. An Atlas of Freshwater Testate Amoebae. Oxford University Press, Oxford.

Stump, A. B. 1959. Mitosis in the Rhizopod Lesquereusia spiralis. J. Protozool., 6:185-189.

Freeman, C. J. 1974. Shell formation, cell division and longevity in Lesquereusia spiralis (Ehrenberg) Penard and Pontigulasia vas (Leidy) Schouteden. PhD Thesis, Univ. S.C., 66 pp.

Harrison, F. W., Dunkelberger, D., Watanabe, N. & Stump, A. B. 1975. The cytology of the testaceous rhizopod Lesquereusia spiralis (Ehrenberg) Penard. I. Cytochemistry. Acta histochem., 54:71-77.

Harrison, F. W., Dunkelberger, D., Watanabe, N. & Stump, A. B. 1976. The cytology of the testaceous Rhizopod Lesquereusia spiralis (Ehrenberg) Penard. II. Ultrastucture and shell formation. J. Morph., 150:343-358.