159,886 species and infraspecific names are in the database, 22,563 images, 61,918 bibliographic items, 468,533 distributional records.

Eupodiscus Bailey, 1851, nom. et typ. cons.

Empire Eukaryota
Kingdom Chromista
Phylum Bacillariophyta
Subphylum Bacillariophytina
Class Mediophyceae
Subclass Thalassiosirophycidae
Order Eupodiscales
Family Eupodiscaceae

Holotype species: Eupodiscus radiatus Bailey

Original publication and holotype designation: Bailey, J.W. (1851). Microscopical observations made in South Carolina, Georgia and Florida. Smithsonian Contributions to Knowledge 2(8): 1-48, pl. 1-3.
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Cox, E.J. (2015). Coscinodiscophyceae, Mediophyceae, Fragilariophyceae, Bacillariophyceae (Diatoms). In: Sylabus of plant families. Adolf Engler's Syllabus der Pflanzenfamilien. 13th Ed. Photoautotrophic eukaryotic algae Glaucocystophyta, Cryptophyta, Dinophyta/Dinozoa, Heterokontophyta/Ochrophyta, Chlorarachniophyta/Cercozoa, Euglenophyta/Euglenozoa, Chlorophyta, Streptophyta p.p. (Frey, W. Eds), pp. 64-103. Stuttgart: Borntraeger Science Publishers.

Description: Cells solitary, discoid. Plastids not observed. Occurring in marine habitats; probably epiphytic or even benthic but not often recorded except in loose-lying populations on coastal sediments; such material may be fossil since there seem to be no records of living cells. Valves circular, with a radiating system of raised hexagonal thickenings. Within the hexagons rows of pores occur and overall these form a radiating system. Each hexigon corresponds to an areola; these are loculate, opening to the outside by several tiny pores and to the inside by a fairly small foramen. Within the locules the foramen has a slightly raised rim and is open, whilst on the internal surface of the valve there is a dome that suggests there may be some form of closing membrane; we have not been able to study the detail. The margin of the valve face is 'scalloped' forming a narrow ridge or wing. Interrupting the ridge are four equally spaced low ocelli. The valve mantle has continuing rows of fine pores but is also variously ornamented with spines, dendritic outgrowths, etc., and often has a circumferential ridge above the outwardly turned mantle edge. The internal openings of the ocelli are sunken. The ocellus pores are round and arranged in more-or-less concentric rows. According to Sullivan (1986), there are no portulae present in this genus (there are none in our material) but in material photographed by Sims there are minute rimoportulae on the mantle between the ocelli (P.A. Sims, personal communication). In many species the internal and external development of the rimoportula is very slight. Copulae not studied.

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

Comments: There has been confusion in the taxonomy and E. Radiatus Bail. has been conserved over E. (Tripodiscus) germanicus Enr. Little seems to be known about the ecology and distribution of this characteristic genus.

Numbers of names and species: There are 66 species names in the database at present, as well as 2 infraspecific names. Of the species names, 8 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):

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Verification of data
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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: 23 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=44396

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Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 19 January 2021.

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