(Hustedt) Johansen and Sray 1998 Category: Symmetrical biraphid
BASIONYM: Navicula krasskei Hustedt 1930
Contributor: Rex Lowe - January 2015
Length Range: 8-9 µm
Width Range: 3-3.8 µm
Striae in 10 µm: 38
Valves are small and lanceolate, with acute apices. The sternum and central nodule are prominent and distinctly thickened. The proximal raphe ends are also prominent, while the distal raphe ends are difficult to resolve in LM. Lyre-shaped depressions are present on both sides of the sternum. Striae are not visible with the light microscope. SEM reveals striae are present and comprised of single rows of areolae. The depressions contain small costae (microcostae). In living cells two plastids are present, pressed to the cingulum.
Populations in the US are more narrow than those of the original description in Europe (Hustedt 1930).
Basionym: Navicula krasskei
Author: Hustedt 1930
Length Range: 6-15 µm
Width Range: 4-5 µm
Striae in 10 µm: not given
Hustedt, F. (1930). Bacillariophyta (Diatomeae). In: Die Subwasser Flora Mitteleuropas. (A. Pascher, ed.),10, Gustav Fischer, Jena. 468 pp.
Johansen, J.R. and Sray, J.C. (1998). Microcostatus gen. nov., a new aerophilic diatom genus based on Navicula krasskei Hustedt. Diatom Research 13(1): 93-101.
Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Süsswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Most common in subaerial habitats such as wetwalls and spray zones.
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.