Kützing 1844 Category: Symmetrical biraphid
BASIONYM: Diadesmis confervacea Kützing 1844
SYNONYM(S): Navicula confervacea (Kützing) Grunow in Van Heurck 1880
Contributor: Pat Kociolek - March 2011
Length Range: 14-18 µm
Width Range: 6.5-7.5 µm
Striae in 10 µm: 18-21
Valves are elliptical with apices protracted in larger specimens. Central area broad and rounded, continuing into the axial area, which tapers toward the ends. There is a rounded central nodule visible when focusing on the interior of the valve. The raphe is straight and filiform and may be missing due to secondary filling during silicification. The striae are radiate, punctate, crossed by longitudinal wavy lines, and of variable length.
This species is typically found in quiescent waters living in chains aligned valve face to valve face.
Basionym: Diadesmis confervacea
Author: Kützing 1844
Length Range: µm
Striae in 10 µm:
DIADESMIS CONFERVACEA. Taf. 30. Fig. 8. (420/1). D. laevis articulata, articulis diametro duplo brevioribus, altero latere lanceolatis, utrinque acuminatis acutis. Long. (Navicularum) Unter Conferven aus dem „River Maraval” der Insel Trinidad: Krüger! (Herb, Sonder.)
Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.
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.
Rosowski, J.R. (1980). Valve and band morphology of some freshwater diatoms. II. Integration of valves and bands in Navicula confervacea var. confervacea. J. Phycol. 16: 88-101.
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.