(Agardh) Williams and Round 1986 Category: Araphid
BASIONYM: Diatoma fasciculata C. Agardh 1812
SYNONYM(S): Fragilaria fasciculata (C. Agardh) Lange-Bertalot 1980 | Echinella fasciculata (Agardh) Jurgens 1816-1822 | Ctenophora pulchella var. fasciculata (Agardh ex specim., Kützing) Schonfeldt 1907
Contributor: Pat Kociolek - March 2011
Length Range: 34-100 µm
Width Range: 4.5-6.0 µm
Striae in 10 µm: 12-15
Valves are linear-lanceolate to lanceolate, with some specimens slightly or even distinctly asymmetric to the transapical axis, although this is not characteristic of the species. The apices are set off slightly and rounded but not capitate. The axial area is very broad and the width can be variable within populations. No central area is evident. The length:breadth ratio is also variable, even in this more restricted sense of the species (as compared to the interpretation of Krammer and Lange-Bertalot 1991). Striae are costate, areolae are not visible in the LM. Both apices appear to have small pore fields.
Patrick (in Patrick and Reimer 1996, p. 141) gives a detailed review of the nomenclature of this species.
Basionym: Diatoma fasciculata
Author: C. Agardh 1812
Length Range: µm
Striae in 10 µm:
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.
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.
Williams, D.M. and Round, F.E. (1987). Revision of the genus Fragilaria. Diatom Research 2: 267-288.
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.