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Navicula radiosa

Kütz. 1844      Category: Symmetrical biraphid

Navicula pseudolanceolata


Navicula recens

LM scalebar = 10 µm = 40 pixels.


Contributor: Marina Potapova - March 2011
Length Range: 52-105 µm
Width Range: 8.8-11.2 µm
Striae in 10 µm: 9-11


The valves are narrow and lanceolate, with acutely rounded ends. The axial area is narrow and linear. The central area is rhombic. The raphe is straight with proximal ends that are hooked to the secondary side. The transapical striae are strongly radiate, bent in the valve center and convergent near the poles. Lineolae number 28-32 in 10 μm.

Note that this concept of N. radiosa is similar to that of Lange-Bertalot (2001) and includes considerable morphological variation, especially in the overall shape of the valve and in the shape of the apices. Further investigations may reveal pseudocryptic species within N. radiosa.

Original Description

Author: Kütz. 1844
Length Range: 75 µm
Striae in 10 µm: 6.6-8.0

Original Description

  1. NAVICULA RADIOSA. Taf. 4. Fig. XXIIl, (420/1). N. mediocris lanceolata, gracilίs, acuta, striis radiantibus distinctis, in 1/100’’’15-18. Long.1/30‘‘‘ In Süsswassergräben bei Halle! Weissenfels ! Nordhausen! — Die Streifen sind stärker und deutlicher als bei N. gracilis, der sie übrigens sehr ähnlich ist.

Original Images

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

Species: Navicula radiosa

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Kützing, F.T. (1844). Die kieselschaligen Bacillarien oder Diatomeen. Nordhausen. 152 pp., 30 pls.

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)

Original INA

California Academy of Sciences (CAS)

Navicula radiosa CAS

NCBI Genbank Taxonomy

Navicula radiosa NCBI

North American Diatom Ecological Database (NADED)


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 radiosa

EMAP Response Plots

Navicula radiosa

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.