Wallace 1960 Category: Symmetrical biraphid
BASIONYM: Navicula notha Wallace 1960
REPORTED AS: Navicula heimansioides (Krammer and Lange-Bertalot 1991)
Contributor: Marina Potapova - February 2011
Length Range: 18.7-39.3 µm
Width Range: 4.1-5.5 µm
Striae in 10 µm: 14-17
Valves are lanceolate to linear-lanceolate with slightly drawn-out ends. Axial area is narrow, central area is small, rhomboid to elliptical. Proximal raphe ends are noticeably deflected to the primary side. Striae are radiate and bent at valve center, convergent at apices, 14-17 in 10 μm. There are 36-40 lineolae in 10 μm.
Note that this concept of Navicula notha is different from that presented in Krammer & Lange-Bertalot (1991) and Lange-Bertalot (1993, 2001) who distinguished N. notha and N. heimansioides. Most studied populations of N. notha from USA, including the type population from Virginia, had both relatively small specimens that fit Lange-Bertalot's concept of N. notha (length equal or less than 32 μm) and large specimens fitting the concept of N. heimansioides (length equal or greater than 30 μm). A morphometric study across several USA populations failed to reveal any breaks in distribution of size and striae density. SEM examination of large and small specimens from the type material did not show any ultrastructural differences. Therefore, we consider N. heimansioides to be a part of N. notha.
Basionym: Navicula notha
Author: Wallace 1960
Length Range: 19-31 µm
Width Range: 4-4.5 µm
Striae in 10 µm: 16-17
Valvis angustis lanceolatis 19-31 μ longis, 4-4.5 μ latis, prope apices paullo concavis, apicibus breve productis vel subcapitatis, striis medis radiantibus, terminalibus parallelis vel vix convergentibus, 16-17 in 10 μ.
Krammer, K. and Lange-Bertalot, H. (1991). Bacillariophyceae. 3. Teil: Centrales, Fragilariaceae, Eunotiaceae. . In Ettl, H., Gerloff, J., Heynig, H. & Mollenhauer, D. (Eds.). Süsswasserflora von Mitteleuropa. 2(3): 1-576. Gustav Fisher Verlag, Stuttgart, Germany.
Lange-Bertalot, H. (1993). 85 Neue taxa und uber 100 weitere neu definierte Taxa erganzend zur Subwasserflora von Mittleuropa. Bibliotheca Diatomologica 27, 454 p. Cramer, Berlin, Stuttgart.
Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.
Wallace, J. (1960). New and variable diatoms. Notulae Naturae 331: 1-8.
Characteristic for soft waters of low nutrient content.
Sampling for 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). Streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming). Over 1200 sites on 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.