(Ehrenberg) O. Müller 1895 Category: Epithemioid
BASIONYM: Eunotia gibberula Ehrenberg 1843
SYNONYM(S): Epithemia gibberula (Ehrenberg) Kützing 1844
Contributor: Elaine Jordan - June 2015
Length Range: 27-43 µm
Width Range: 5-9.5 µm
Striae in 10 µm: 12-23 (ventral)
Valves are lunate, with strongly convex dorsal margins that are often slightly notched in the middle. The ventral margin is slightly concave to straight. In girdle view, frustules are widely lanceolate to elliptic and the width ranges from 11-16.5 µm. The apices can be slightly bent ventrally or may be protracted and rounded. The raphe is positioned on the dorsal margin. The transapical costa density ranges from 4-7 in 10 µm on the ventral margin, with 2-6 striae in between each costa. Costae are parallel at the valve center to slightly slightly radiate toward the apices.
Patrick and Reimer (1975) report valve lengths up to 70 µm.
Basionym: Eunotia gibberula
Author: Ehrenberg 1843
Length Range: µm
Striae in 10 µm:
E. gibberula, punctato-striata parva, dorso late elato, apicibus leviter re-volutis constrictis. Icon?
Bahls, L. (2009). A checklist of diatoms from inland waters of the northwestern United States. Proceedings of the Academy of Natural Sciences of Philadelphia. 158: 1-35.
Blinn, D. (1993). Diatom community structure along physicochemical gradients in saline lakes. Ecology 74: 1246-2363.
Ehrenberg, C.G. (1843). Verbreitung und Einfluß des mikroskopischen Lebens in Süd- und Nord-Amerika. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin, 1841: 291-445, 4 Tafel.
Fritz, S., Cumming, B., Gasse, F., and Laird, K. (1999). Diatoms as indicators of hydrologic and climatic change in saline lakes. In: The Diatoms: Applications for the Environmental and Earth Sciences, Cambridge University Press, pp. 41-72.
Iltis, A. (1972). Algues des eaux natroiiées du Kanem (Tchad). Cahiers ORSTOM, Sér. Hydrobiol. VI (3-4): 173-246.
Krammer, K. and Lange-Bertalot, H. (1991). Bacillariophyceae. 3. Teil: Centrales, Fragilariaceae, Eunotiaceae. In Ettl, H., Gerloff, J., Heynig, H. & Mollenhauer, D. (Eds.). Süsswasserflora von Mitteleuropa. 2(3): 1-576. Gustav Fisher Verlag, Stuttgart, Germany.
Müller, O. (1900). Bacillariaceen aus den Natronthälern von El Kab (Ober-Aegypten). Hedwigia 38(5-6):274-288, 289-321. .
Nelson, A. and Kashima, K. (1993). Diatom zonation in southern Oregon tidal marshes relative to vascular plants, foraminifera, and sea level. Journal of Coastal Research 9: 673-697.
Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Smol, J.P. and Stoermer, E.F. (2010). The Diatoms: Applications for the Environmental and Earth Sciences, Second Edition. Cambridge University Press, 667 p.
Rhopalodia gibberula was found in a benthic periphyton mat in Silver Lake Fen and in epipelion in moist soil of Excelsior Fen, both of Dickinson County, Iowa. This taxon has also been reported from California, Idaho, Montana, North Dakota, South Dakota, and Wyoming (Bahls 2009), as well as in saline lakes in western North America (Blinn 1993). The range of conductivity where it has been reported is wide, from low to moderately high conductivity (Patrick and Reimer 1975). Rhopalodia gibberula has also been found in silty and sandy marshes and identified along four different intertidal zones of southern Oregon (Nelson and Kashima 1993). In addition, Rhopalodia gibberula septae are commonly found in fossil records because they are heavily silicified (Fritz et al. 1999).
Rhopalodia species are known to grow in nitrogen-poor habitats because they are hosts to endosymbiotic cyanobacteria, which fix atmospheric nitrogen.
Distribution of Rhopalodia gibberula in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 03 June 2015.
Credit/Source: USGS BioData
Distribution of Rhopalodia gibberula in rivers of Alaska based on the National Water Quality Assessment program. Retrieved 03 June 2015.
Credit/Source: USGS BioData
Distribution of Rhopalodia gibberula in rivers of Hawaii based on the National Water Quality Assessment program. Retrieved 03 June 2015.
Credit/Source: USGS BioData
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.