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Navicula subrhynchocephala

Hust. 1935      Category: Symmetrical biraphid

Navicula subconcentrica


Navicula subrostellata

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - March 2011
Length Range: 29-42 µm
Width Range: 7.5-8.9 µm
Striae in 10 µm: 12-14


Valves are linear-lanceolate with variable apices, from subrostrate to capitate. The axial area is narrow and straight. The central area is rounded and slightly asymmetrical. The raphe is straight, with dilated external proximal raphe ends that are hooked towards the secondary side of the valve. The terminal raphe fissures are hooked to the secondary valve side. Striae are radiate, becoming parallel then convergent at the apices. The striae near the center are straight or very slightly bent. The areolae are clearly visible under LM, and number appoximately 24-25 in 10 μm.

Original Description

Author: Hust. 1935
Length Range: 35-45 µm
Width Range: 6-8 µm
Striae in 10 µm: 13-16

Original Description

Navicula subrhynchocephala nov. spec. Schalen lanzettlich mit vorgezogenen, schwach kopfig gerundeten Enden, 35-45 μ lang, 6-8 μ, breit. Raphe gerade, Endspalten nach gleichen Seiten abgebogen. Axialarea sehr eng, linear, Zentralarea quer elliptisch, ziemlich groß. Transapikalstreifen im mittleren Teil der Schale wenig radial, an den Enden konvergent, 13-16 in 10 μ, zart liniert (Taf. I, Fig. 11) .

Original Images

Cite This Page:
Potapova, M. (2011). Navicula subrhynchocephala . In Diatoms of the United States. Retrieved May 23, 2018, from

Species: Navicula subrhynchocephala

Contributor: Marina Potapova

Reviewer: Mark Edlund, Rex Lowe


Hustedt, F. (1935). Die fossile Diatomeenflora in den Ablagerungen des Tobasees auf Sumatra. "Tropische Binnengewasser, Band VI". Archiv für Hydrobiologie, Supplement 14:143-192.

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

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Navicula subrhynchocephala CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46560

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

Navicula subrhynchocephala

EMAP Response Plots

Navicula subrhynchocephala

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.