Eunotia rhomboidea

Hustedt 1950      Category: Eunotioid
BASIONYM: Eunotia rhomboidea Hustedt 1950

Eunotia papilioforma

 

Eunotia richbuttensis

LM scalebar = 10 µm = 80 pixels.



Observations

Contributor: Paula Furey - December 2011
Length Range: 18.0-25.6 µm
Width Range: 2.7-3.8 µm
Striae in 10 µm: 15-17 in the center valve

Description

Frustules in girdle view appear rhomboid. Valves are more or less asymmetric to the apical and transapical axes, with one apex wider than the other. The ventral margin is straight to weakly concave, and the dorsal margin is convex. The apices are rounded. The helictoglossae lie close to or are a short distance from the apices. The distal raphe end curves a short distance onto the valve face. Striae are evenly spaced becoming slightly denser near the valve apices.

Some specimens have been observed with one apical rimoportula (Furey et al. 2011, pl 31 fig. 8) and in other specimens, a rimoportula is absent (Siver et al. 2005 pl 28, fig. 1,3,4).



Original Description

Basionym: Eunotia rhomboidea
Author: Hustedt 1950
Length Range: 15-20 µm
Width Range: 2-4 µm
Striae in 10 µm: 16-18

Original Description

  1. Eunotia rhomboidea nov. spec. Zellen in Gürtelbandansicht rhomboidisch. Schalen mit geradem bis wenig konkavem Ventral- und nur schwach konvexem Dorsalrand und stumpf gerundeten Enden, oft unsymmetrisch, etwa 15-20 µ lang und 2-4 µ breit. Endknoten sehr klein, Rapheenden in der Valvarfläche kaum sichtbar. Transapikalstreifen etwa 16-18 in 10 µ, an den Enden etwas dichter als in der Mitte, aber sorest ziemlich regelm Big gestellt. Taf. XXXVI, Fig. 34-41. Taf. XXXIV, Fig. 28. Sehr häufig im Litoral des Pinnsees, vereinzelt auch im Grundlosen Kolk bei Min . Unterscheidet sich von ähnlichen kleinen Arten, wie Eunotia tenella, E. exigua u. a., insbesondere durch die schiefwinklige Gürtelbandansicht, die beim ersten Anblick als Anomalie oder auch als Präparationsprodukt erscheinen ‘nag. Es handelt sich hier jedoch um eine konstante Eigentümlichkeit, die die sowohl zeitlich als örtlich getrennten Individuen auszeichnet. Ich gebe auf Taf. XXXIV, Fig. 28, eine Photographic aus dem litoralen Aufwuchs im Pinnsee, auf der neben einzelnen Schalenansichten zahlreiche Zellen in Gürtelbandlage erkennbar sind, zum Teil in kurzen Bändern, die naturgemäß ebenfalls schief orientiert sind.

Original Images


Cite This Page:
Furey, P. (2011). Eunotia rhomboidea. In Diatoms of the United States. Retrieved October 31, 2014, from http://westerndiatoms.colorado.edu/taxa/species/eunotia_rhomboidea

Species: Eunotia rhomboidea

Contributor: Paula Furey

Reviewer: Marina Potapova

Citations

Furey, P.C., Lowe, R.L. and Johansen, J.R. (2011). Eunotia Ehrenberg (Bacillariophyta) of the Great Smoky Mountains National Park, USA. Bibliotheca Diatomologica 56: 1-134.

Hustedt, F. (1950). Die Diatomeenflora norddeutscher Seen mit besonderer Berücksichtigung des holsteinischen Seengebiets V-VII. Seen in Mecklenburg, Lauenburg und Nordostdeutschland. Archiv für Hydrobiologie 43:329-458, Tafs 21-41.

Siver, P.A., Hamilton, P.B., Stachura-Suchoples, K. and Kociolek, J.P. (2005). Diatoms of North America. The Freshwater Flora of Cape Cod. Iconographia Diatomologica 14: 1-463.

Wuthrich, M. (1975). Contribution à la connaissance de la flore algologique du Parc National Suisse. Le Diatomées. [Résultats des recherches scientifiques au Parc National suisse]. Druck Lüdin, AG Liestal. Band XIV: 273-369.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Eunotia rhomboidea CAS

North American Diatom Ecological Database (NADED)

NADED ID: 33051

Autecology Discussion

Eunotia rhomboidea has been found in streams, including as epilithon and epiphytic on bryophytes.

EMAP Assessment

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.


EMAP Distribution

Eunotia rhomboidea


EMAP Response Plots

Eunotia rhomboidea


EMAP citations

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.