Synedra goulardii

Bréb. ex Cleve and Grunow 1880      Category: Araphid
SYNONYM(S): Fragilaria ulna var. goulardi (Bréb.) Lange-Bert. 1980 

Synedra famelica


Synedra mazamaensis

LM scalebar = 10 µm = 40 pixels.


Contributor: Ian Bishop - November 2015
Length Range: 33-119 µm
Width Range: 8.5-10.5 at center; 8.6-12.4 at maximum µm
Striae in 10 µm: 9-12


Valves are linear-lanceolate with a distinctly constricted mid-valve. The apices are rostrate to subcapitate, and apiculate. The axial area is linear and very narrow. The central area is large, circular, and sometimes asymmetric. Smaller specimens may have short marginal striae in the center valve. Striae are parallel, becoming slightly radiate at the apices. Ghost striae are present in the central area, although they are more visible in larger specimens. Each valve has two rimoportula, with a rimoportula positioned at each apex.

Original Description

Author: Bréb. ex Cleve and Grunow 1880
Length Range: 57-80 µm
Width Range: 9, 8 in the middle µm
Striae in 10 µm: 10.5

Original Description

S. Goulardi Brébisson in litteris. Schaalen in der Mitte etwas verengt, an den Enden zugespitzt, 0,057-0,080 mm. breit, in der Mitte 0,008 mm., Querstreifen 10 1/2 in 0,01 mm., an den Enden schwach radial in der Mitte auf einem fast quadratischen Raume sehr matt (bei schwacher Vergrösserung fehlend). Buenos Ayres, Portorico, Kamtschatka, Jenissey. Taf. VI, Fig. 119 200/1.

Original Images

Cite This Page:
Bishop, I. (2015). Synedra goulardii. In Diatoms of the United States. Retrieved April 23, 2018, from

Species: Synedra goulardii

Contributor: Ian Bishop

Reviewer: Eduardo A. Morales


Cleve, P.T. and Grunow, A. (1880). Beiträge zur Kenntniss der Arktischen Diatomeen. Kongliga Svenska-Vetenskaps Akademiens Handlingar, 17(2): 121 pp., 7 pls.

Schwarzwalder, R.N. and Postek, M.T. (1981). Valve morphology of Synedra goulardi (Bacillariophyceae). Journal of Phycology 17: 412-414.

Williams, D. M. (1986). Comparative morphology of some species of Synedra Ehrenb. with a new definition of the genus. Diatom Research, 1 (1): 131-152.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Synedra goulardi CAS

North American Diatom Ecological Database (NADED)

NADED ID: 66065

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

Synedra goulardi

EMAP Response Plots

Synedra goulardi

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.