(Ehrenberg) O. Müller 1895 Category: Epithemioid
BASIONYM: Navicula gibba Ehrenberg 1830
Contributor: Pat Kociolek - March 2011
Length Range: 75-205 µm
Width Range: 8-11 µm
Striae in 10 µm: 12-16
Valves usually seen in girdle view. Valves are linear, with apices bent towards the ventral margin. The central valve is inflated, often with a visible “notch” on the dorsal margin. The raphe is positioned in a canal along the dorsal margin, and the proximal raphe ends and helictoglossae are not evident. Costae are prominent, and extend across the valve face. Between each costa are between 2 and 3 rows of singly punctate striae. Costae number 5-8 in 10 µm.
This species is usually an epiphyte, but may also be found in the benthos. Both Patrick & Reimer (1966) and Krammer and Lange-Bertalot (1988) give dimensions of up to 300 µm in length.
Basionym: Navicula gibba
Author: Ehrenberg 1830
Length Range: µm
Striae in 10 µm:
Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.
Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.
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.