(Thwaites in W. Smith) Grunow in Cleve and Grunow 1880 Category: Nitzschioid
BASIONYM: Denticula sinuata Thwaites in W. Smith 1856
REPORTED AS: Nitzschia sinuata (Krammer and Lange-Bertalot 1988, p. 52, fig. 40: 1-4.)
Contributor: Loren Bahls - January 2014
Length Range: 23-44 µm
Width Range: 6.2-8.5 µm
Striae in 10 µm: 18-21
Valves are linear-lanceolate, with triundulate margins and capitate apices. Fibulae are very large, occupy about one-half the valve face, and number 3-7 in 10 µm. Striae are distinctly punctate and weakly radiate. The raphe appears to be continuous through the central valve, as the central fibulae lack a distinctive gap. (Note that some authors express this feature by stating that the “central nodule is absent”).
Basionym: Denticula sinuata
Author: Thwaites in W. Smith 1856
Length Range: µm
Striae in 10 µm:
Cleve, P.T. and Grunow, A. (1880). Beiträge zur Kenntniss der Arktischen Diatomeen. Kongliga Svenska-Vetenskaps Akademiens Handlingar, 17(2): 121 pp., 7 pls.
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.
Smith, W. (1856). Synopsis of British Diatomaceae. John Van Voorst, London 1856. 2: 107pp., pls. 32-60, 61-62, A-E.
Nitzschia sinuata var. sinuata is uncommon in the benthos of shallow calcareous lakes and ponds of the northern Rocky Mountains. Here it is found at pH values ranging from 8.50 to 9.05 and specific conductance levels ranging from 105 to 181 µS/cm.
Lower Wolverine Pond, Ten Lakes Scenic Area, Kootenai National Forest, Lincoln County, Montana: home of Nitzschia sinuata var. sinuata.
Credit/Source: Loren Bahls
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.