Category: Symmetrical biraphid
BASIONYM: Navicula cuspidata var. halophila Grunow in Van Heurck 1885
REPORTED AS: Navicula halophila (Patrick and Reimer 1966, p. 467, plate 44, fig. 4)
Contributor: Loren Bahls - October 2012
Length Range: 33-52 µm
Width Range: 8.7-12.4 µm
Striae in 10 µm: 17-19
Valves are rhombic lanceolate with acute apices, or very subtly protracted apices in small specimens. The axial area is very narrow. The central area is small and elliptic in shape. The raphe is filiform with straight, weakly expanded proximal ends and distal ends that are hooked to the same side. Striae are parallel to weakly radiate at the valve center, becoming convergent towards the apices. Areolae are fine and difficult to resolve in LM.
Basionym: Navicula cuspidata var. halophila
Author: Grunow in Van Heurck 1885
Length Range: µm
Striae in 10 µm:
var. halophila Grun. (Atl. Suppl. fig. 30.— in Type Ν° 12.) Etroit, très-petit : environ 5 c.d.m. ; stries délicates, 16 environ en 1 c.d.m., radiantes vers la partie moyenne, convergentes aux extrémités. Saumâtre. — Blankenberghe.
Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.
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.
Craticula halophila is widely distributed in streams acros the Northwestern Great Plains, where it prefers waters with high levels of dissolved solids (Montana Diatom Collection). There are 50 confirmed records of this taxon in the Montana Diatom Collection.
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.
The name, Craticula halophila, was originally applied to the specimens currently shown on the page for C. buderi. That page was revised and this page was opened. - S. Spaulding