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Amphora copulata

(Kütz.) Schoeman and R.E.M.Archibald 1986      Category: Asymmetrical biraphid
BASIONYM: Frustulia copulata Kütz. 1833

Amphora calumetica


Amphora minutissima

LM scalebar = 10 µm = 40 pixels.


Contributor: Joshua Stepanek | Pat Kociolek - January 2011
Length Range: 12-62 µm
Width Range: 4-10 µm
Striae in 10 µm: 14-17


Valves semi-lanceolate to semi-elliptical, dorsal margin smoothly arched, ventral margin concave. Valve ends narrowly rounded. Axial area narrow, raphe arched and positioned towards the ventral margin with proximal and distal ends deflected dorsally. Dorsal fascia distinct, round to elliptical and typically “closed” to the axial area and dorsal margin by a row of short striae. Ventral fascia typically longitudinally wider than dorsal and extending to the ventral margin. Dorsal striae weakly radiate in central area becoming more radiate at apices, and broken longitudinally by intercostal ribs. Thickened hyaline bar often visible on the dorsal margin separating vale face and mantle. Ventral striae uninterrupted, radiate in the middle, becoming convergent towards the apices and consisting of a single areola.

Original Description

Basionym: Frustulia copulata
Author: Kütz. 1833
Length Range: µm
Striae in 10 µm:

Original Description

Frustulis sparsis lanceolatis acutis, apicibus hyalinis, binalim copulatis, opposite incurvatis, luteo-fuscis, medio subinflatis et macula hyalina orbiculari notatis.

Unter schwarzbraunem Schaume, der sich am Uter eines kleinen Baches bei Bruckdorf unweit Halle gebildet hatte, sie war noch mit Frustulia acuminata vermischt und schein ganz bewegungslos.

Original Images

Cite This Page:
Stepanek, J., and Kociolek, P. (2011). Amphora copulata. In Diatoms of the United States. Retrieved May 26, 2018, from

Species: Amphora copulata

Contributor: Joshua Stepanek | Pat Kociolek

Reviewer: Sarah Spaulding


Lee, K. and Round, F.E. (1988). Studies on freshwater Amphora species. II. Amphora copulata (Kütz.) Schoeman & Archibald. Diatom Research 3(2): 217-225. 10.1080/0269249X.1988.9705034

Schoeman, F.R. and Archibald, R.E.M. (1986). Observations on Amphora species (Bacillariophyceae) in the British Museum (Natural History) V. Some species from the subgenus Amphora. Journal of South African Botany 52(5):425-437.

Siver, P.A. and Hamilton, P.B. (2011). Diatoms of North America: The Freshwater Flora of Waterbodies on the Atlantic Coastal Plain. Iconographia Diatomologica 22.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Amphora copulata CAS

NCBI Genbank Taxonomy

Amphora copulata NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 7075

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

Amphora copulata

EMAP Response Plots

Amphora copulata

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.