(Patrick) Potapova 2013 Category: Symmetrical biraphid
BASIONYM: Navicula gravistriata Patrick 1959
Contributor: Marina Potapova - February 2013
Length Range: 11-21 µm
Width Range: 4.0-6.7 µm
Striae in 10 µm: 11-13
Valves are rhombic-lanceolate with attenuate apices. The striae are uniseriate, slightly radiate in the center and almost parallel or slightly convergent at the ends. Areolae are slit-shaped and number 42-50 in 10 mm. The central area is transverse and rectangular. The raphe is filiform and has tear-drop shaped distal and proximal ends. A row of areolae is present at the valve apex. The valvocopula are deep.
Basionym: Navicula gravistriata
Author: Patrick 1959
Length Range: 12-22 µm
Width Range: 4-7 µm
Striae in 10 µm: 11-13
Patrick, R.M. (1959). New species and nomenclatural changes in the genus Navicula (Bacillariophyceae). Proceedings of the Academy of Natural Sciences of Philadelphia 111 (1959): 91-108 . http://www.jstor.org/stable/4064508
Potapova, M. (2013). The types of 22 Navicula (Bacillariophyta) species described by Ruth Patrick. Proceedings of the Academy of Natural Sciences of Philadelphia 162: 1-23.
Hippodonta gravistriata have been reported from the tidal zones of the Sabine River, Texas, and from the Patuxent and Potomac Rivers, Maryland.
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.