Kociolek and Stoermer 1988 Category: Asymmetrical biraphid
BASIONYM: Gomphoneis eriense var. variabilis Kociolek and Stoermer 1988
Contributor: Pat Kociolek - February 2011
Length Range: 25-45 µm
Width Range: 9.5-12 µm
Striae in 10 µm: 10-13 in the center, 14-16 at the poles
Valves are lanceolate-clavate, with a distinctly protracted, broadly rounded head-pole, a robust to linear central portion of the valve and a distinctly rounded footpole. Smaller valves are elliptical-clavate, with the headpole protracted slightly. Striae are radiate at the central portion of the valve and strongly radiate at the poles. The raphe is undulate and lateral. The axial area is narrow, widening slightly towards the central area. A small, barely circular central area with a single stigma is present. The striae have individual areolae observable with DIC or oblique light in the light microscope. Longitudinal lines are distinct near the axial area, less so at the apices. Apical pore fields are present at the footpole.
Gomphoneis eriense var. variabilis is widely distributed throughout western North America.
Basionym: Gomphoneis eriense var. variabilis
Author: Kociolek and Stoermer 1988
Length Range: µm
Striae in 10 µm:
Kociolek, J.P. and Stoermer, E.F. (1988). Taxonomy, ultrastructure and distribution of Gomphoneis herculeana, G. eriense and closely related species (Naviculales: Gomphonemataceae). Proc. Acad. Nat. Sci. Phil. 140: 24-97. http://www.jstor.org/stable/4064935
NADED ID: 36002
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.