Rhopalodia
O. Muller 1895 Category: Epithemioid
TYPE SPECIES: Rhopalodia gibba (Ehrenberg) O. Müller
Image Credit: Ditmar Metzeltin, Marina, Potapova, Pat Kociolek
CLASS: Bacillariophyceae
ORDER: Rhopalodiaceae
FAMILY: Rhopalodiaceae
- Symmetry dorsiventral
- Raphe positioned in dorsal keel
- Valve faces nearly planar
Frustules of Rhopalodia have a strong dorsiventral symmetry. The raphe is positioned on the dorsal side of each valve in a shallow keel. The valve faces are nearly planar, that is, each frustule is shaped like 1/2 of an orange. The central endings of the raphe are expanded. The raphe is supported internally by costae. In contrast to Epithemia, Rhopalodia lacks complex cingula (girdle bands).
Cells of Rhopalodia grow in nitrogen poor habitats. Like Epithemia, cells typically include endosymbiotic cyanobacteria that fix atmospheric nitrogen.
Cite This Page:
Spaulding, S., and Metzeltin, D. (2011). Rhopalodia. In Diatoms of the United States. Retrieved June 18, 2013, from http://westerndiatoms.colorado.edu/taxa/genus/rhopalodia
Contributor: Sarah Spaulding | Ditmar Metzeltin - March 2011
Citations
Drum, R. and Pankratz, S. (1964). Fine structure of an unusual cytoplasmic inclusion in the diatom genus Rhopalodia. Protoplasma 60 (1): 141-149. 10.1007/BF01248136
Geitler, L. (1977). Zur Entwicklungsgeschichte der Epithemiaceen Epithemia, Rhopalodia und Denticula (Diatomophyceae) und ihre vermutlich symbiotischen Sphäroidkörper . Plant Systematics and Evolution 128 (3-4): 259-275. 10.1007/BF00984562
Kneip, C., Voss, C., Lockhart, P.J. and Maier, U.G. (2008). The cyanobacterial endosymbiont of the unicellular algae Rhopalodia gibba shows reductive genome evolution. Evolutionary Biology 8:30. 10.1186/1471-2148-8-30
Krammer, K. (1988). The gibberula-group in the genus Rhopalodia O. Müller (Bacillariophyceae). II: Revision of the group and new taxa. Nova Hedwigia 47 (1-2): 159-205.
Müller, O. (1895). Rhopalodia ein neues Genus der Bacillariaceen . (Engler's) Botanische Jahrbucher fur Systematik, Pflanzengeschichte, und Pflanzengeographie, Leipzig, 22: 54-71 .
Prechtl, J., Kneip, C. Lockhart, P., Wenderoth, K. and Maier, U.G. . (2004). Intracellular spheroid bodies of Rhopalodia gibba have nitrogen-fixing apparatus of cyanobacterial origin. Molecular Biology and Evolution 21(8): 1477-1481. 10.1093/molbev/msh086
You, Q., Liu, Y., Wang, Y. and Wang, Q. (2009). Taxonomy and distribution of diatoms in the genera Epithemia and Rhopalodia from the Xinjiang Uygur Autonomous Region, China. Nova Hedwigia 89:397-430. 10.1127/0029-5035/2009/0089-0397