Nitzschia sociabilis

Hust. 1957      Category: Nitzschioid

Nitzschia sinuata var. tabellaria


Nitzschia valdecostata

LM scalebar = 10 µm = 80 pixels.


Contributor: Kalina Manoylov - October 2011
Length Range: 22-50 µm
Width Range: 3.5-4.5 µm
Striae in 10 µm: > 35


Frustules are lightly silicified. In girdle view, valves are sigmoid and narrow. Girdle bands are absent. Valves are lanceolate to rhomboid with sharp apices. Striae are not resolvable with light microscopy. The fibulae are irregularly spaced and number 8-11 in 10 µm. Fibulae, however, are not widely spaced at the central part of the valve.

Original Description

Author: Hust. 1957
Length Range: 20-40 µm
Width Range: 3-4 µm
Striae in 10 µm:

Original Description

German: Schalen typisch lanzettlich mit spitzen, nicht vorgezogenen Enden, 20-40 µm, lang, 3-4 µm breit. Kiel stark exzentrisch, Kielpunckte durchschnittlich etwa 10 in 10 µm, mehr oder weniger unregelmäßig gestellt, transapikal strichförmig. Struktur äußerst zart, bisher nicht aufgelöst. Abb.91-94.

Latin: Valvae lanceolatae apicibus acutis non protractis, 20-40 µm longae, 3-4 µm latae. Carina valde excentrica punctis carinalibus plus minusvae 10 in 10 µm, transapicaliter elongatis, irregulariter positis. Structura delicatissima, striae transapicales inconspicuae.

Original Images

Cite This Page:
Manoylov, K. (2011). Nitzschia sociabilis. In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Nitzschia sociabilis

Contributor: Kalina Manoylov

Reviewer: Marina Potapova


Hustedt, F. (1957). Die Diatomeenflora des Flußsystems der Weser im Gebiet der Hansestadt Bremen. Abhandlungen des Naturwissenschaftlichen Verein zu Bremen 34(3):181-440.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Nitzschia sociabilis CAS

North American Diatom Ecological Database (NADED)

NADED ID: 48225

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

Nitzschia sociabilis

EMAP Response Plots

Nitzschia sociabilis

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.