158,893 species and infraspecific names are in the database, 22,385 images, 61,555 bibliographic items, 457,092 distributional records.

Actinoptychus Ehrenberg, 1843

Lectotype species: Actinoptychus senarius (Ehrenberg) Ehrenberg

Original publication:Ehrenberg, C.G. (1843). Verbreitung und Einfluss des mikroskopischen Lebens in Süd- und Nord-Amerika. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin 1841: 291-445 + [1, Berichtigungen], + 4 pls.
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Type designated in Boyer, C.S. (1927). Synopsis of North American Diatomaceae. Part I - Coscinodiscatae, Rhizosolenatae, Biddulphiatae, Fragilariatae. Proceedings of the Academy of Natural Sciences of Philadelphia 78(Suppl.): 1-228.
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Fourtanier, E.J. & Kociolek, J.P. (2009). Catalogue of diatom names: Part II: Abas through Bruniopsis. Occasional Papers of the California Academy of Sciences 156(II): 1-231, 2 figs, 1 table.

Taxonomic notes
According to CAS "There is a description of the genus p. 400 (p. 112 of reprint), and description of five species of Actinoptychus p. 409-410 (p. 121-122 of reprint): A. hexapterus, A. nonarius, A. denarius, A. vicenarius, A. jupiter; there is also an illustration of A. senarius (I/I/27) and A. nonarius (I/III/22). No type is designated in the original publication. Boyer gives A. senarius as the type accompanied by a querry. Actinoptychus was first introduced (but not validly published) in Ehrenberg 1841 (ref. 000953) as a subgenus of Actinocyclus. No diagnosis was given, and four species were included in the group p. 137, 140-141: Actinocyclus (Actinoptychus) senarius, A. sedenarius, A. octodenarius and A. duodenarius." - (20 Oct 2011) - M.D. Guiry

Description: Cells discoid, solitary. Very common in neritic collections, probably mainly a component of the assemblage lying loose or attached to other algae on coastal sediments. Plastids several, irregular plates. Many fossil species. Valves sectored (6 in the common A. senarius [= A. undulatus] but up to 20 others) so that alternate sectors are elevated or depressed. Central area plain or granulate. Areolae in radiate striae, opening by simple pores to the outside but over much of the surface the silica is corrugated or pitted, delimiting groups of areolae. Internally, uneroded areolae are closed by domed vela. External tubes of rimoportulae prominent, usually located at distal points on radii of elevated sectors. Depressions (termed pseudopores by Andrews, 1979) occur at the corresponding position on the depressed sectors. The internal openings of the rimoportulae tend to lie at right angles to the valve margin and are either straight or curved. Valve framework bullulate. Margin of valve face often produced into a thickened rim or marked with special ornamentation below which the distinctively patterned valve mantle extends. The valve mantle often has spines, wart-like outgrowths, siliceous ridges, etc., and the edge is produced into a smooth flange. Copulae plain, split and wide.

The most recent alteration to this page was made on 14 Aug 2017 by M.D. Guiry.

Comments: Andrews (1979) shows that the arrangement of rimoportulae can vary, with more than one in each raised sector, and that they can also occur on the edge of the depressed sectors, at least in A. heliopelta. A genus with numerous species and varieties (VanLandingham records 150 possible valid species) many of which require re-investigation. Its ecology also requires further study. The primary valves were formerly described as the genus Debya Pantoscek.

Numbers of names and species: There are 225 species names in the database at present, as well as 107 infraspecific names. Of the species names, 46 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.

Scott, F.J. & Thomas, D.P. (2005). Diatoms. In: Antarctic marine protists. (Scott, F.J. & Marchant, H.J. Eds), pp. 13-201. Canberra & Hobart: Australian Biological Resources Study; Australian Antarctic Division.

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

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: 14 August 2017 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43721

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 15 August 2020.

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