Hyalosphenia Stein 1859

Introduction

About 20 species, type species: H. ligata (Tatem, 1870), Synonym: H. cuneata Schulze, 1875.

Characteristics

Species with compressed, chitinoid transparent shell with no foreign material; aperture often with a thickened lip. Two principal shell types: wedge-shaped or flask-shaped. All species have an ovular nucleus, some like H. papilio have a symbiosis with Zoochlorellae. The cell is fixed in the test by long epipodes (see title illustrations).

Discussion of Phylogenetic Relationships

In a first SSU rRNA-tree the genus is not monophyletic and Hyalosphenia papilio and H. elegans are mixed in a clade with Nebela spp. (Lara et al. 2008).

Ecology

The most common species of the wedge-shaped cell type is H. papilio Leidy, 1879. It is a dominant species in the green parts of wet sphagnum and therefore an excellent indicator in palaeoecological studies. H. elegans is a typical flask-shaped species, it is herbivorous and common in mosses and acid soils.

References

Bonnet, L. 1989. Données écologiques sur quelques Hyalospheniidae et Paraquadrulidae (Thécamoebiens) des sols (Première partie). Bull. Soc. Hist. Nat. Toulouse, 125:17-22.

Grospietsch, T. 1965. Monographische Studie der Gattung Hyalosphenia STEIN, (Rhizopoda, Testacea). Hydrobiologia, 26:211-241.

Charret, R. 1964. Contribution a l'étude cytologique et biologique de Hyalosphenia papilio (Leidy), Rhizopode Testacé. Bull. Biol. France Belg., 98:369-390.

Lara, E., Heger, T.J., Ekelund, F, Lamentowicz and Mitchell, E.A.D. 2008: Ribosomal RNA Genes challenge the monophyly of the Hyalospheniidae (Amoebozoa: Arcellinida). Protist 159: 165-176.

Meisterfeld, R. 1977. Die horizontale und vertikale Verteilung der Testaceen (Rhizopoda, Testacea) in Sphagnum. Arch. Hydrobiol., 79:319-356.

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

Schönborn, W. 1962. Die Stratigraphie lebender Testaceen im Sphagnetum der Hochmoore. Limnologica, 1:315-321.