Diatoma
Bory de Saint-Vincent 1824 Category: Araphid
TYPE SPECIES: Diatoma vulgaris Bory de Saint-Vincent
Image Credit: Marina Potapova
CLASS: Fragilariophyceae
ORDER: Fragilariales
FAMILY: Fragilariaceae
- Transverse costae distinct
- Striae uniseriate
- Single rimoportula
The genus Diatoma possesses characteristic thickened transverse costae, septae are absent. Each valve has a single rimoportula, positioned near a valve terminus and oriented transapically. The phylogenetic relationships within the genus have been investigated (Williams 1985) and two subgenera are currently recognized.
Subgenus Diatoma: The striae of the subgenus are comprised of uniseriate rows. Internal transapical ribs are prominent, raised, and extend from the sternum to both mantles. The tip of the valve mantle is connected by an overlapping internal rim. Spines are scattered near the polar pore fields, but are absent elsewhere. Living cells contain numerous discoid or platelike plastids. Examples of species within the subgenus include, Diatoma vulgare Bory and Diatoma tenue Ag.
Subgenus Odontidium: The sternum of the subgenus is wide and diffuse. Spines are present, but are considered non-functional. The cingulum, or girdle bands, are differentiated into three components. The copulae possess porose ligulae. Living cells contain multiple elliptical lobed plastids. Examples: Diatoma mesodon (Ehrenb.) Kütz. and Diatoma hiemale (Roth) Heib.
Cite This Page:
Spaulding, S., and Edlund, M. (2008). Diatoma. In Diatoms of the United States. Retrieved June 19, 2013, from http://westerndiatoms.colorado.edu/taxa/genus/Diatoma
Contributor: Sarah Spaulding | Mark Edlund - December 2008
Citations
Kociolek, J.P. and Lowe, R.L. (1983). Scanning electron microscopic observations on the frustular morphology and filamentous growth habit of Diatoma heimale var. mesodon. Trans. Amer. Micro. Soc. 102: 281-287.
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.
Potapova, M. and Snoeijs, P. (1997). The natural life cycle in wild populations of Diatoma moniliformis (Bacillariophyceae) and its disruption in an aberrant environment. Journal of Phycology 33: 924-937. 10.1111/j.0022-3646.1997.00924.x
Sicko-Goad, L. and Stoermer, E.F. (1979). A morphological study of lead and copper effects on Diatoma tenue var. elongatum (Bacillariophyta). Journal of Phycology 15: 316-321.
Snoeijs, P. and Potapova, M. (1998). Ecotypes or endemic species? A hypothesis on the evolution of Diatoma taxa (Bacillariophyta) in the northern Baltic Sea. Nova Hedwigia 67: 303-348.
Williams, D.M. (1985). Morphology, taxonomy and inter-relationships of the ribbed araphid diatoms from the genera Diatoma and Meridion (Diatomaceae: Bacillariophyta). Bibliotheca Diatomologica 8: 1-228.
Williams, D.M. (1990). Cladistic analysis of some freshwater araphid diatoms (Bacillariophyta) with particular reference to Diatoma and Meridion. Plant Systematics and Evolution 171: 1615-6110.