(Kützing) Kützing 1844 Category: Asymmetrical biraphid
BASIONYM: Frustulia ovalis Kützing 1833
SYNONYM(S): Navicula amphora Ehrenberg
Valves are semi-elliptical with a smoothly arched dorsal margin and slightly concave ventral margin. Valve ends are rounded. The axial area is narrow. An uninterrupted raphe ledge (a thin, elevated T shaped structure that extends laterally to the raphe) is present. The raphe ledge is visible extending the length of the cell, covering the dorsal and ventral striae near the axial area. The raphe is linear and arched dorsally. Proximal and distal raphe ends are deflected dorsally. Dorsal striae are interrupted transapically by intercostal ribs and are slightly radiate centrally, becoming more radiate towards the apices. Ventral striae consist of an uninterrupted row of single areolae, slightly radiate centrally becoming convergent at the apices. A dorsal fascia is absent; a ventral fascia is present, extending to the ventral margin.
Basionym: Frustulia ovalis
Author: Kützing 1833
Length Range: µm
Striae in 10 µm:
Krammer, K. (1980). Morphologic and taxonomic investigations of some freshwater species of the diatom genus Amphora Ehr. Bacillaria 3:197-225.
Kützing, F.T. (1844). Die kieselschaligen Bacillarien oder Diatomeen. Nordhausen. 152 pp., 30 pls.
Lee, K. and Round, F.E. (1987). Studies on freshwater Amphora species. I. Amphora ovalis. Diatom Research 2 (2): 193-203.
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. South African Journal of Botany. 53: 425-437.
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.