155,805 species and infraspecific names are in the database, 21,968 images, 60,221 bibliographic items, 439,336 distributional records.

Cyclotella (Kützing) Brébisson, 1838, nom. et typ. cons.

Classification:
Empire Eukaryota
Kingdom Chromista
Phylum Bacillariophyta
Subphylum Bacillariophytina
Class Mediophyceae
Subclass Thalassiosirophycidae
Order Stephanodiscales
Family Stephanodiscaceae

Holotype species: Cyclotella tecta Håkansson & R.Ross

Currently accepted name for the type species: Cyclotella distinguenda Hustedt

Original publication:Brébisson, [L.] A. de (1838). Considerations sur les diatomées et essai d'une classification des genres et des espèces appartenant à cette famille, par A. de Brébisson, auteur de la Flore de Normandie, etc. pp. [i], [1]-20, [4, err.]. Falaise & Paris: Brée l'Ainée Imprimeur-Libraire; Meilhac.
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Type designated in Håkansson, H. & Ross, R. (1984). Proposals to designate conserved types for Cymbella C. Agardh and Cyclotella (Kützing) Brébisson, and to conserve Rhopalodia O. Müller against Pyxidicula Ehrenberg (all Bacillariophyceae). Taxon 33: 525-531.
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Nakov, T., Guillory, W.X., Julius, M.L., Theriot, E.C. & Alverson, A.J. (2015). Towards a phylogenetic classification of species belonging to the diatom genus Cyclotella (Bacillariophyceae): Transfer of species formerly placed in Puncticulata, Handmannia, Pliocaenicus and Cyclotella to the genus Lindavia. Phytotaxa 217(3): 249-264.

Description: Cells short, drum-shaped, free-living or forming filaments, chains or rarely clusters, united by mucilage. Plastids numerous, discoid. Mainly freshwater and planktonic, with two species occurring in shallow coastal waters, probably as an evolutionary invasion from brackish waters. Valves circular (oval and triangular species have been found in fossil material from the Miocene, and oval ones very rarely in modern samples), with either a tangential or concentric undulation of the valve face. Rows of areolae extending from valve centre (or absent from centre), becoming grouped into fascicles on the outer region of valve face, and continuing to the valve edge without a break; no distinctive valve mantle in most species; scattered areolae in the central region in some species. Central area often ornamented with warts, granules, etc., small warts or spines often scattered between the areolae on the valve mantle, forming patterns. Openings of portules flush with valve surface, often on hyaline ridges or strips and sometimes surrounded by spines, one of which may be prominent. Mantle edge often banded by a grooved thickening. Areolae poroidal, closed internally by cribra. Fultoportulae present in a ring near the valve margin and often also scattered over the centre of the valve. Wall infolded in marginal area with fultoportulae opening on ridges; sometimes with secondary ridges within the folds which may be expanded into chambers. Rimoportulae few, lying on the folds or at the edge of the central area. Copulae numerous, split.

The most recent alteration to this page was made on 19 Oct 2015 by M.D. Guiry.

Comments: A fairly well circumscribed genus of around 100 spp. Differs from Stephanodiscus in the nature of the central area, absence of a distinct single ring of spines, absence or only slight development of the external tubes of the portules, and the distinct folding or chambering of the interior of the valve margin. For details and comparison with other 'cyclostephanoid' genera, see Theriot, Stoermer & Håkansson (1987). There are many problems in the LM identification of species. C. meneghiniana is very common and has been discussed and figured in detail by Schoeman & Archibald (180). Further details of this can be found in Hoops & Floyd (1979).

Numbers of names and species: There are 333 species names in the database at present, as well as 113 infraspecific names. Of the species names, 118 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..

Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):

Click here to also show infraspecific names in the list below.

References
Hustedt, F. (1930). Bacillariophyta (Diatomeae) Zweite Auflage. In: Die Süsswasser-Flora Mitteleuropas. Heft 10. (Pascher, A. Eds), pp. [i]-vii, [1]-466. Jena: Verlag von Gustav Fischer.

Tomas, C.R., Eds (1996). Identifying marine diatoms and dinoflagellates. pp. 1-858. San Diego: Academic Press Inc.

Håkansson, H. (2002). A compilation and evaluation of species in the genera ["general"] Stephanodiscus, Cyclostephanos and Cyclotella with a new genus in the family Stephanodiscaceae. Diatom Research 17(1): 1-139, 487 figs.

Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.

Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Created: 11 April 2002 by M.D. Guiry

Verified by: 19 October 2015 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43757

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 16 July 2019.

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