Eunotia sudetica

O.Müll. 1898      Category: Eunotioid

Eunotia subherkiniensis


Eunotia superbidens

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - August 2013
Length Range: 22-43 µm
Width Range: 5.0-7.6 µm
Striae in 10 µm: 10-15


Valves are dorsiventral. The dorsal margin is moderately arched, somewhat convex to nearly flat (or weakly concave in larger specimens) and subtly biundulate. The ventral margin is weakly concave to nearly flat. Apices are rostrate, broadly rounded and distinctly set off from the high dorsal ‘shoulders’. Terminal raphe ends are positioned on the ventral margin, some distance from the apices. Striae are weakly radiate, composed of fine areolae and nearly evenly spaced, although an occasional short stria may be interspersed along the dorsal margin. Under the SEM, the areolae can be seen to lie in separate depressions and number about 30 in 10 µm. Internally, the raphe fissure terminates in a raised helictoglossa.

Original Description

Author: O.Müll. 1898
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bahls, L. (2013). Eunotia sudetica. In Diatoms of the United States. Retrieved April 23, 2018, from

Species: Eunotia sudetica

Contributor: Loren Bahls

Reviewer: Rex Lowe


Alles, E., Nörpel-Schempp, M. and Lange-Bertalot, H. (1991). Taxonomy and ecology of characteristic Eunotia species in headwaters with low electric conductivity. Nova Hedwigia 53: 171-213.

Lange-Bertalot, H., Bak, M., Witkowski, A. and Tagliaventi, N. (2011). Eunotia and some related genera. Diatoms of the European Inland Waters and Comparable Habitats. 6: 747 pp.

Müller, O. (1898). Bacillariales aus den Hochseen des Riesengebirges. Forschungsber. Biol. Stat. Plön 6: 1-40.

Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Siver, P.A., Hamilton, P.B., Stachura-Suchoples, K. and Kociolek, J.P. (2005). Diatoms of North America. The Freshwater Flora of Cape Cod. Iconographia Diatomologica 14: 1-463.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Eunotia sudetica CAS

North American Diatom Ecological Database (NADED)

NADED ID: 33059

Autecology Discussion

Patrick and Reimer (1966) report Eunotia sudetica from acid to circumneutral waters in Pennsylvania and the southeastern United States. Siver et al. (2005) report this species from two acidic ponds on Cape Cod, Massachusetts. Lange-Bertalot et al. (2011) report that E. sudetica prefers small, running waters or wet bryophyte habitats. The one record of this species in the Montana Diatom Collection is from a lake high in the Sierra Nevada Mountains of California (photo below).

In Europe, E. sudetica is found in waters with a pH optimum of 5.0, specific conductance under 100 µm and tannic waters with high concentrations of fulvic acids (Alles et al. 1991). It was reported to be in waters with slightly elevated sulfate and aluminum concentrations.


Evolution Lake at an elevation of 3,313 m in the Sierra Nevada Range of central California, home of Eunotia sudetica.


EMAP Assessment

The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.

EMAP Distribution

Eunotia sudetica

EMAP Response Plots

Eunotia sudetica

EMAP citations

Results are published in:

Johnson, T., Hermann, K., Spaulding, S., Beyea, B., Theel, C., Sada, R., Bollman, W., Bowman, J., Larsen, A., Vining, K., Ostermiller, J., Petersen, D. Hargett, E. and Zumberge, J. (2009). An ecological assessment of USEPA Region 8 streams and rivers. U.S. Environmental Protection Agency Region 8 Report, 178 p.

Stoddard, J. L., Peck, D. V., Olsen, A. R., Larsen, D. P., Van Sickle, J., Hawkins, C. P., Hughes, R. M., Whittier, T. R., Lomnicky, G. A., Herlihy, A. T., Kaufman, P. R., Peterson, S. A., Ringold, P. L., Paulsen, S. G., and Blair, R. (2005). Environmental Monitoring and Assessment Program (EMAP) western streams and rivers statistical summary. U.S. Environmental Protection Agency Report 620/R-05/006, 1,762 p.

Stoddard, J. L., Peck, D. V., Paulsen, S. G., Van Sickle, J., Hawkins, C. P., Herlihy, A. T., Hughes, R. M., Kaufman, P. R., Larsen, D. P., Lomnicky, G. A., Olsen, A. R., Peterson, S. A., Ringold, P. L., and Whittier, T. R. (2005). An ecological assessment of western streams and rivers. U.S. Environmental Protection Agency Report 620/R-05/005, 49 p.