(Hustedt) Bukhtiyarova and Round 2007 Category: Monoraphid
BASIONYM: Achnanthes austriaca var. helvetica Hustedt 1933
Contributor: Marina Potapova - May 2010
Length Range: 12-26 µm
Width Range: 5.1-7.8 µm
Striae in 10 µm: 24-30
Valves are linear-elliptical. The raphe valve has a linear axial area and a bow tie-shaped central area. The raphe has long terminal fissures curved to opposite sides. The central raphe ends are slightly expanded externally. The central raphe ends curve toward opposite sides internally. The rapheless valve has a narrow linear axial area and a large rounded, hexagonal or diamond-shaped central area. Striae are radiate on both valves, 24-30 in 10 µm, interrupted at the valve margin. The external openings of the areolae on the valve face are circular to slightly elongated. The areolae are often visible in LM near the central area of the rapheless valve. One row of elongated areolae is present on the mantle of both the rapheless and raphe valves; a second row is present on the valve margin at the valve apices.
Basionym: Achnanthes austriaca var. helvetica
Author: Hustedt 1933
Length Range: µm
Striae in 10 µm:
Schalen typisch elliptisch, die Raphenschalen mit deutlich punktierten Transapikalstreifen (Fig. 831 g-k).
Bukhtiyarova, L. and Round, F. E. (1996). Revision of the genus Achnanthes sensu lato. Psammothidium, a new genus based on Achnanthidium marginulatum. Diatom Research 11: 1-30.
Hustedt, F. (1933). Die Kieselalgen Deutschlands, Österreichs und der Schweiz unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete. In: L. Rabenhorst (ed.), Kryptogamen Flora von Deutschland, Österreich und der Schweiz. Akademische Verlagsgesellschaft m.b.h. Leipzig, Vol. 7, Part 2, pp. 321-432.
Manoylov, K.M. (2007). On some Psammothidium species from rivers in the United States. Diatom Research 22(2): 317–327.
Monnier, O., Lange-Bertalot, H., Hoffmann, L. and Ector, L. (2007). The genera Achnanthidium Kützing and Psammothidium Bukhtiyarova et Round in the family Achnanthidiaceae (Bacillariophyceae): a reappraisal of the differential criteria. Cryptogamie, Algologie 28:1 41-158.
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.