Ehrenberg 1840 Category: Asymmetrical biraphid
BASIONYM: Gomphonema coronatum Ehrenberg 1840
SYNONYM(S): Gomphonema acuminatum var. coronatum (Ehrenberg) Rabenhorst 1864
Contributor: Pat Kociolek - September 2011
Length Range: 34-108 µm
Width Range: 8-13 µm
Striae in 10 µm: 8-12, approaching 15/10 µm at the footpole
Valves are acuminate-apiculate. A small, acute to blunt protracted headpole is present, while the footpole is rounded. The broadest portion of the valve is near the headpole and/or the central portion of the valve. This feature appears to be population-dependent. Initial valves lack the acuminate structure and appear rounded at the poles and tumid in the middle. The axial area is straight, forming a transverse central area. The striae about the central area are more separate from one another. On one side of the central area there is a shortened stria, on the opposite side the central stria terminates at the stigma. The raphe is lateral and undulate. The punctate striae are radiate about the center, becoming parallel toward the poles returning to radiate at the headpole and strongly radiate towards the footpole.
Basionym: Gomphonema coronatum
Author: Ehrenberg 1840
Length Range: µm
Striae in 10 µm:
Reichardt, E. (1999). Zur Revision der Gattung Gomphonema: Die Arten um G. affine/insigne, G. angustatum/micropus, G. acuminatum sowie gomphonemoide Diatomeen aus dem Oberoligozän in Böhmen. Annotated Diatom Micrographs. Edited by Horst Lange-Bertalot. Iconographia Diatomologica, Volume 8, A.R.G. Gantner.
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.
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.