Lange-Bertalot in Krammer and Lange-Bertalot 1985 Category: Symmetrical biraphid
SYNONYM(S): Navicula leptocephala Brébisson ex Grunow in Van Heurck
Contributor: Marina Potapova - May 2009
Length Range: 21-36 µm
Width Range: 5–7 µm
Striae in 10 µm: 12–14
Valves are lanceolate with acutely rounded ends. The raphe is filiform. The central portions of the raphe branches and proximal raphe ends are deflected toward the primary side. Terminal raphe fissures are hooked towards the secondary side. The axial area is narrow and linear. The central area is asymmetric, “bow-tie” shaped on the primary side and crescent-shaped at the secondary side. The lineolate striae are radiate, becoming convergent at the valve apices. Striae number 12-14 in 10 µm and areolae number 30-35 in 10 µm.
Krammer, K. and Lange-Bertalot, H. (1985). Naviculaceae Neue und wenig bekannte Taxa, neue Kombinationen und Synonyme sowie Bemerkungen zu einigen Gattungen. Bibliotheca Diatomologica 9:5-230, 43 pls.
N. erifuga prefers brackish water or fresh water of high mineral content, eutraphentic.
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.