Craticula
Grunow 1867 Category: Symmetrical biraphid
TYPE SPECIES: Craticula perrotetii Grunow
Image Credit: Lauren Fuelling, Pat Kociolek
CLASS: Bacillariophyceae
ORDER: Naviculales
FAMILY: Stauroneidaceae
- Striae parallel, or nearly parallel
- Valves lanceolate, with narrowly rostrate or capitate poles
- Distinct internal valves may be present
The valves of Craticula are lanceolate, with narrowly rostrate or capitate poles. The striae are distinctly parallel, or nearly parallel. The genus is polymorphic, forming different valve morphologies. Distinct internal valves, called craticula, are formed in response to osmotic stress. Note that these craticular stages are not always present. Living cells possess two elongate, plate-like chloroplasts appressed to the girdle.
Craticula is a term applied to internal valves that are formed within frustules that are normal in morphology. The craticular valves consist of a raphe-sternum and robust transverse bars. The genus Craticula occurs in epipelic habitats across North America, in fresh to brackish waters.
Cite This Page:
Spaulding, S., and Edlund, M. (2008). Craticula. In Diatoms of the United States. Retrieved July 24, 2014, from http://westerndiatoms.colorado.edu/taxa/genus/Craticula
Contributor: Sarah Spaulding | Mark Edlund - December 2008
Citations
Lange-Bertalot, H., Cavacini, P., Tagliaventi, N. and Alfinito, S. (2003). Diatoms of Sardinia: Rare and 76 new species in rock pools and other ephemeral waters. Iconographia Diatomologica 12, 438 pp.
Mann, D.G. and Stickle, A. (1991). The genus Craticula. Diatom Research 6: 79-107.
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.