Craticula
Grunow 1867 Category: Symmetrical biraphid
TYPE SPECIES: Craticula perrotetii Grunow
Smallest to largest - 15 taxa sorted by maximum length
Craticula accomoda
Craticula accomodiformis
Craticula acidoclinata
Craticula ambigua
Craticula buderi
Image Credit: Lauren Fuelling, Pat Kociolek
CLASS: Bacillariophyceae
ORDER: Naviculales
FAMILY: Stauroneidaceae
- Striae parallel, or nearly parallel
- Valves lanceolate
- Central area small or absent
- Distinct internal valves may be present
The valves of Craticula are lanceolate. The striae are distinctly parallel, or nearly parallel. The central area is greatly reduced or absenct. The genus is polymorphic, forming different valve morphologies. There are three valve types found for this taxon: vegetative, “heribaudii”, and craticula forms. The three forms are produced as a cellular strategy for surviving conditions such as desiccation (Schmid 1979). Two craticula are formed within the vegetative frustule. Subsequently the “heribaudii” cell is formed within the craticula. The heribaudii cell usually has different ornamentation compared to vegetative cell. Note that these stages are not always present in population, and for many of the smaller species, the craticular and heribaudi stages have not been observed. 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 October 01, 2016, from http://westerndiatoms.colorado.edu/taxa/genus/Craticula
Contributor: Sarah Spaulding | Mark Edlund - December 2008
Reviewer: Sam Rushforth - April 2010
Citations
Grunow, A. (1867). Reise seiner Majestät Fregatte Novara um die Erde. Botanischer Theil. 1. Algen. Wein, aus der Kaiselich-Königlichen Hof-und Staasdruckerei, pp. 1-104., 11 pls.
Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.
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.
Morales, E. and Le, M. (2005). The taxonomy of the diatom Lacunicula sardiniensis Lange-Bertalot, Cavacini, Tagliaventi et Alfinito and its relationship with the genus Craticula Grunow (Bacillariophyceae). Proceedings of the Academy of Natural Sciences of Philadelphia 154:155-161.
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.
Schmid, A.M. (1979). Influence of environmental factors on the development of the valve in diatoms. Protoplasma 99: 99-115. 10.1007/BF01274072
Van De Vijver, B., Kopalová, K. and Zidarova, R. (2015). Three new Craticula species (Bacillariophyta) from the Maritime Antarctic Region. Phytotaxa 213(1): 35-45 . 10.11646/phytotaxa.213.1.3