LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Paula Furey - March 2012
Length Range: 13-16 µm
Width Range: 1.9-2.1 µm
Striae in 10 µm: 18-22 in the center valve
Description
Frustules are narrow and rectangular in girdle view. Ventral margins are weakly concave, with two slight swellings marking the position of the proximal raphe ends. Dorsal margins are irregular and weakly triundulate, with the central undulation most prominent. Valve ends are protracted and capitate to subcapitate. Helitoglossae are located close to the apices. The raphe extends in a short curve on to the valve face. Striae are parallel. The areolae are unresolved in the LM. One apical rimoportula is located just above the center of the apex.
Original Description
Basionym: Eunotia microcephala
Author: Krasske 1932
Length Range: 10-15 µm
Width Range: 2-3 µm
Striae in 10 µm: 18-22
Original Description
Original Images
Cite This Page:
Furey, P. (2012). Eunotia microcephala. In Diatoms of the United States. Retrieved September 28, 2016, from http://westerndiatoms.colorado.edu/taxa/species/eunotia_microcephala
Species: Eunotia microcephala
Contributor: Paula Furey
Reviewer: Marina Potapova
Image Credit: Paula Furey
- Ventral margin weakly concave
- Dorsal margin with central undulation
- Apices capitate to subcapitate
Ventral margins are weakly concave, with two slight swellings marking the position of the proximal raphe ends. Dorsal margins are irregular andly weakly triundulate, with the central undulation being most prominent. Valve ends are protracted and capitate to subcapitate. Helictoglossae are located close to the apices. The raphe extends in a short curve on to the valve face.
Compare
The morphology of E. microcephala is most similar to E. trinacria and E. rushforthii. The central undulation on the dorsal margin of E. microcephala is more prominent than the faint hint of a swelling on the dorsal margin of E. microcephala. The two ventral undulations are more prominent on valves of E. microcephala than those on valves of E. trincacria and are not visible on E. rushforthii.
Eunotia rushforthii
Eunotia trinacria
Citations
Furey, P.C., Lowe, R.L. and Johansen, J.R. (2011). Eunotia Ehrenberg (Bacillariophyta) of the Great Smoky Mountains National Park, USA. Bibliotheca Diatomologica 56: 1-134.
Krammer, K. and Lange-Bertalot, H. (1991). Bacillariophyceae. 3. Teil: Centrales, Fragilariaceae, Eunotiaceae. In Ettl, H., Gerloff, J., Heynig, H. & Mollenhauer, D. (Eds.). Süsswasserflora von Mitteleuropa. 2(3): 1-576. Gustav Fisher Verlag, Stuttgart, Germany.
Krasske, G. (1923). Die Diatomeen des Casseler Beckens und seiner Randgebirge, nebst einigen wichtigen funden aus Niederhessen. Botanisches Archiv. Konigsberg 3(4):185-209.
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.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
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 microcephala
Distribution
The distribution map represents the relative abundance of this Eunotia microcephala in the western EMAP study. Relative abundance is a measure of the proportion of cells of this species based on a "fixed count" of 300 total diatom cells counted and identified. Each of the western EMAP sample sites is shown, either with a black dot for sites where Eunotia microcephala was not recorded, or with a red circle indicating the relative abundance of Eunotia microcephala.
Note that the size of the proportional symbols varies between species to help show both abundant and rare species.
Scale for the map to the left
EMAP Response Plots
Eunotia microcephala
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.