Navicula oppugnata

Hustedt 1945      Category: Symmetrical biraphid
BASIONYM: Navicula oppugnata Hustedt 1945

Navicula oblonga


Navicula peregrina

LM scalebar = 10 µm = 40 pixels.


Contributor: Loren Bahls - October 2012
Length Range: 29-41 µm
Width Range: 8.6-10.1 µm
Striae in 10 µm: 9-11


Valves are lanceolate with obtusely rounded apices. Axial area is narrow and completely filled by the lateral raphe. Central area is small and irregular, typically bordered by alternately short-long-short striae on one or both sides. The distinctly lateral raphe becomes reverse lateral near the proximal ends, which are bent to the secondary side and distinctly inflated. Striae are radiate, becoming parallel to weakly convergent near the apices. Areolae are coarse and number 24-26 in 10 µm.

Original Description

Basionym: Navicula oppugnata
Author: Hustedt 1945
Length Range: 44 µm
Width Range: 10 µm
Striae in 10 µm: 12

Original Description

Schalen lanzettlich mit kaum merklich vorgezogenen, ziemlich spitz gerundeten Enden, um 44 µ lang, etwa 10 µ breit. Raphe gerade, mit etwas seitlich abgebogenen Zentralporen, Axialarea schmal linear, um den Zentralknoten plötzlich zu einer kleinen, querelliptischen Zentralarea erweitert. Transapikalstreifen im mittleren Teil radial und mit vereinzelten eingeschobenen kürzeren Streifen, an den Enden senkrecht zur Mittellinie, 12 in 10 µ, grob liniert, Längslinien etwa 25 in 10 µ, dem Schalenrand annähernd parallel, um den Zentralknoten nach aussen konvexe Bogen bildend.

Original Images

Cite This Page:
Bahls, L. (2012). Navicula oppugnata. In Diatoms of the United States. Retrieved October 21, 2016, from

Species: Navicula oppugnata

Contributor: Loren Bahls

Reviewer: Marina Potapova


Hustedt, F. (1945). Diatomeen aus Seen und Quellgebieten der Balkan-Halbinsel. Archiv für Hydrobiologie 40(4):867-973.

Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.

Simonsen, R. (1987). Atlas and Catalogue of the Diatom Types of Friedrich Hustedt. J. Cramer, Berlin & Stuttgart 1: 525 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Navicula oppugnata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46979

Autecology Discussion

These images are from a population living in Sheridan Lake in the Black Hills National Forest, western South Dakota. Here, on the sample date, pH measured 9.73 and specific conductance measured 327 µS/cm. Lange-Bertalot (2001) reports this taxon from eutrophic to mesotrophic, calcium-rich standing waters in Europe. This taxon has been recorded infrequently in the United States.

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

Navicula oppugnata

EMAP Response Plots

Navicula oppugnata

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.