Identification key to the Euglypha species living in Sphagnum
Translated and adapted from the following sources: (Cash & Wailes 1915; Corbet 1973; Grospietsch 1958; Harnisch 1958; Luftenegger et al. 1988; Ogden & Hedley 1980; Penard 1902; Schönborn 1992)
Disclaimer. This is a grossly simplified key of some main types. The true diversity of the genus is much higher both considering described taxa, and certainly even more so if pseudo-cryptic and cryptic taxa are considered. Still imperfect as this document is hopefully it will be useful. Any suggestions for improvement are very welcome!
Copyright Edward Mitchell 2003-. All material can be used freely for non-profit educational purposes. An acknowledgement for such a use would be appreciated.
Version June 5th 2003
1 Test with stout spines 2
No spines, or thin scattered spines (most common species) 6
2 Spines long and sinuous, never straight, pointing backwards with a 45o angle, inserted either only around the neck, or at various distances from the aperture and constituting 2 or 3 rings of spines. Length 60-120 µm E. brachiata
Very wet Sphagnum
Spines inserted all around the edge, or only at the posterior end of the test 3
3 Spines inserted only at the posterior end of the test 5
Spines inserted all around the edge of the test 4
4 Spines pointing in all directions, more or less perpendicular to the test surface
Length 53-70 µm, width 25-35 µm, aperture width 10-14 µm E. filifera
Spines pointing backwards, inserted in the posterior third of the test. Length 53-100 µm, width 28-46 µm, aperture width 14-25 µm E. acanthophora
In fen Sphagnum
5 Test small, less than 90 µm, narrow, length equals three times breadth.
Length 33-80 µm, width 12-23 µm, aperture width 6-12 µm. E. cristata
Test long, over 90 µm, 1-2 long stout spines. Length 108-140 µm.
Wet Sphagnum. E. mucronata
6 Test compressed 7
Test round in cross section E. alveolata group
Three species fall into this group:
- E. alveolata, Length (60)-74-100 µm, scales round or oval. Moss and Sphagnum in bogs, fens, ponds, and springs
- E. tuberculata, scales round or oval. Length 45-100 µm, width 24-50 µm, aperture width 10-20 µm. In fen Sphagnum
- E. scutigera, scales scutiform. Length 75-90 µm
7 Mouth round 8
Mouth oval 9
8 Small species, length usually under 50 µm, without spines. E. rotunda = E. laevis
Length 22-54 µm, width 11-36 µm, aperture width 6-12 µm.
Wet moss, common in fen Sphagnum.
Note: Schönborn (1992) concluded from a clone culture experiment than E. laevis is polymorphic and the range of variations covers the description of E. rotunda. Therefore E. rotunda is included in E. laevis.
Larger species, length usually > 50 µm. Apertural scales clearly larger than the shell scales, aperture usually round or slightly oval Length 45-100 µm, width 30-60 µm, aperture width 12-23 µm. E. strigosa
Spines sometimes absent (form glabra) Moss, bogs, fens, particularly in bog hummocks
9 Test very compressed, angular in cross section. Spines when present stouter than those of E. ciliata and E. strigosa E. compressa
Length 70-132 µm, width 38-80 µm, aperture width 16-28 µm
Test less compressed, oval in cross section, spines usually thinner 10
10 Small species (length 30-60 µm and under), usually < 60 µm, no spines
See taxonomic note above E. rotunda = E. laevis
Larger species (40-100 µm) usually > 50 µm, usually with numerous thin, transparent spines, either along the margins or covering the whole test. 11
11 Apertural scales about the same size as the shell scales E. ciliata
Length usually > 60 µm Spines sometimes absent (form glabra).
In fen Sphagnum, but also reported in many other habitats
Apertural scales clearly larger than the shell scales (about twice as wide) and appearing thicker, aperture usually round or slightly oval E. strigosa
Length usually > 50 µm. Spines sometimes absent (form glabra)
Length 45-100 µm, width 30-60 µm, aperture width 12-23 µm.
Moss, bogs, fens, particularly in bog hummocks
References
Cash, J. & Wailes, H. (1915) The British Freshwater Rhizopoda and Heliozoa Ray Society, London.
Corbet, S.A. (1973) An illustrated introduction to the testate rhizopods in Sphagnum, with special reference to the area around Malham Tarn, Yorkshire. Field Studies, 3, 801-838.
Grospietsch, T. (1958) Wechseltierchen (Rhizopoden) Kosmos Verlag, Stuttgart.
Harnisch, O. (1958). II. Klasse: Wurzelfüssler, Rhizopoda. Die Tierwelt Mitteleuropas, Band 1: Urtiere-Hohltiere-Würmer, Lieferung 1b (eds P. Brohmer, P. Ehrmann & G. Ulmer), pp. 1-75, pls. 1-26. Quelle & Meier, Leipzig.
Luftenegger, G., Petz, W., Berger, H., Foissner, W. & Adam, H. (1988) Morphologic and Biometric Characterization of 24 Soil Testate Amebas (Protozoa, Rhizopoda). Archiv Fur Protistenkunde, 136, 153-189.
Ogden, C.G. & Hedley, R.H. (1980) An atlas to freshwater testate amoebae Oxford University Press, Oxford.
Penard, E. (1902) Les Rhizopodes du bassin du Léman Kündig, Genève.
Schönborn, W. (1992) Adaptive polymorphism in soil-inhabiting testate amoebae (Rhizopoda): Its importance for delimitation and evolution of asexual species. Archiv für Protistenkunde, 142, 139-155.
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