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Diatoms of the United States is now known as Diatoms of North America.
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Diatoma tenuis

C.Agardh 1812      Category: Araphid
SYNONYM(S): Diatoma elongatum var. tenuis (C.Agardh) Van Heurck 
REPORTED AS: Diatoma tenue var. elongatum (Patrick and Reimer 1966) 

Diatoma moniliformis


Diatoma vulgaris

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - June 2010
Length Range: 20-85 µm
Width Range: 2.9-4.9 µm
Striae in 10 µm: 45-60


Cells form zig-zag colonies. Frustules are biconcave in girdle view. In valve view, valves are linear with capitate apices. Valves at the smaller end of the size range have rostrate or subrostrate apices. Transapical ribs number 6-11 in 10 µm. Striae are uniseriate, but not visible under LM. Axial area is linear and very narrow. A rimportula is positioned within in a transapical rib or between ribs at one apex. Apical pore fields are present at both apices.

Original Description

Author: C.Agardh 1812
Length Range: µm
Striae in 10 µm:

Original Description

Diatoma Tenuis, filis decumbentibus linearibus fusco-luteis, articulis post copulationem alternatim solutis. Habitat in foliis dejectis aquaque submersis, ut in rivulo Luci Foglesång prope Ludam, unde inter alias algas apportavit amic. Ph. Doct. Bruzelius.

Original Images

Cite This Page:
Potapova, M. (2010). Diatoma tenuis. In Diatoms of the United States. Retrieved May 24, 2018, from

Species: Diatoma tenuis

Contributor: Marina Potapova

Reviewer: Rex Lowe


Agardh, C.A. (1812). Algarum decas prima. Litteris Berlingianis, Lundae. 56 pp.

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.

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.

Snoeijs, P. and Potapova, M. (1998). Ecotypes or endemic species? A hypothesis on the evolution of Diatoma taxa (Bacillariophyta) in the northern Baltic Sea. Nova Hedwigia 67: 303-348.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Diatoma tenuis CAS

NCBI Genbank Taxonomy

Diatoma tenuis NCBI
Diatoma tenue NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 27012

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

Diatoma tenuis

EMAP Response Plots

Diatoma tenuis

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.