Eunotia
Ehrenberg 1837 Category: Eunotioid
TYPE SPECIES: Eunotia arcus Ehrenberg
Image Credit: Paula Furey
CLASS: Bacillariophyceae
ORDER: Eunotiales
FAMILY: Eunotiaceae
- Valves with a short raphe
- Raphe extends from valve mantle onto valve face
- Striae uniserate
- One rimoportula usually present at valve apex
Members of the Eunotiaceae (Eunotia, Actinella, Amphicampa) are unusual among the raphid diatoms in that frustules have a very short raphe system. The terminal nodules are positioned on the mantle. From the terminal nodule, the raphe slit lies on the valve mantle then slightly, or strongly, curves onto the valve face. As a result of this morphology, raphe branches visible in girdle view.
Valves of Eunotia are asymmetric to the apical axis. The dorsal margin is convex, smooth, or undulate. The ventral margin is straight or concave. Uniseriate striae extend across the valve face. Areolae of the striae generally lack hymenes and other occlusions. Usually one rimoportula present at an apex of each valve, although occasionally there may be two rimoportulae, or they may be absent.
Cells occur singly, free, or attached by mucilaginous stalks, or in long ribbon-like colonies. Species within Eunotia are widespread and diverse in acidic and dystrophic habitats.
Cite This Page:
Furey, P. (2010). Eunotia. In Diatoms of the United States. Retrieved May 25, 2013, from http://westerndiatoms.colorado.edu/taxa/genus/eunotia
Contributor: Paula Furey - October 2010
Citations
Beals, J. and Potapova, M. (2013). Type material of the diatom Eunotia arcuoides Foged. Proceedings of the Academy of Natural Sciences of Philadelphia 162: 25-32.
Furey, P.C., Lowe, R.L. and Johansen, J.R. (2009). Teratology in Eunotia taxa in the Great Smoky Mountains National Park and description of Eunotia macroglossa sp. nov. Diatom Research 24(2):273-290.
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.
Gaiser, E.E. and Johansen, J. (2000). Freshwater diatoms from Carolina bays and other isolated wetlands on the Atlantic Coastal Plain of South Carolina, USA, with descriptions of seven taxa new to science. Diatom Research 15: 75-130.
Hamilton, P.B. and Siver, P.A. (2010). A morphological investigation of Eunotia fennica (Bacillariophyceae) from a freshwater acidic pond in Newfoundland, Canada . Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):89-98. 10.1635/053.160.0110
Mann, D.G., Chepurnov, V.A. and Idei, M. (2003). Mating system, sexual reproduction, and auxosporulation in the anomalous raphid diatom Eunotia (Bacillariophyta). Journal of Phycology 39: 1067-1084. 10.1111/j.0022-3646.2003.03-011.x
Metzeltin, D. (2012). Eunotia langebertalotii, a new species from Lambir Hills National Park in Sarawak, tropical East Malaysia. Nova Hedwigia, Beiheft 141: 125–130.
Metzeltin, D. and Tremarin, P.I. (2011). Uma nova espécie de Eunotia para o sudeste do Brasil: Eunotia fuhrmannii. IHERINGIA, Sér. Bot., Porto Alegre 66(2): 201-208.
Patrick, R.M. (1958). Some nomenclatural problems and a new species and a new variety in the genus Eunotia (Bacillariophyceae). Notulae Naturae 312: 1-15.
Petersen, J.B. (1950). Observations on some small species of Eunotia. Dansk Bot. Ark. 14: 1-19.
Wetzel, C.E., Ector, L., Hoffmann, L. and Bicudo, D.C. (2010). Colonial planktonic Eunotia (Bacillariophyceae) from Brazilian Amazon: Taxonomy and biogeographical considerations on the E. asterionelloides species complex . Nova Hedwigia 91: 49-86. 10.1127/0029-5035/2010/0091-0049