(Grunow) Lowe et al. 2014 Category: Symmetrical biraphid
BASIONYM: Navicula contenta Grunow in Van Heurck 1885
SYNONYM(S): Diadesmis contenta (Grunow) Mann
Contributor: Rex Lowe - January 2015
Length Range: 6-12 µm
Width Range: 2.4-2.6 µm
Striae in 10 µm: 36-38
Cells are linear, with slightly concave or slightly convex margins. The raphe is straight and simple. A central fascia is present, extending from the central nodule to the valve margins. Striae are difficult to resolve using light microscopy. The axial area is broad and linear. In SEM, the proximal raphe ends are bilaterally expanded in a T-shaped depression. The distal raphe ends have a longer bilaterally expanded T-shaped depression. Cells often grow attached to one another in short chains.
Basionym: Navicula contenta
Author: Grunow in Van Heurck 1885
Length Range: 7 µm
Width Range: 2 µm
Striae in 10 µm: 36
Lowe, R.L., Kociolek, J.P., Johansen, J.R., Van de Vijver, B., Lange-Bertalot, H. and Kopalová, K . (2014). Humidophila gen. nov., a new genus for a group of diatoms (Bacillariophyta) formerly within the genus Diadesmis: species from Hawai’i, including one new species. Diatom Research 29(4): 351-360.
Round, F.E., Crawford, R.M. and Mann, D.G. (1990). The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp.
Humidophila contenta is one of the few cosmopolitan species of this genus. It has been reported worldwide in soils and subaerial habitats.
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.