Pleurosira () , 1848
Holotype species: Melosira thermalis Meneghini
Currently accepted name for the type species: Pleurosira thermalis (Meneghini) Meneghini
Original publication and holotype designation: Trevisan, V.B.A. (1848). Saggio di una monografia delle Alghe Coccotalle. pp. 1-112. Padova [Padua]: coi tipi del seminario.
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 cylindrical, united in straight or zig-zag filaments by means of mucilage pads extruded from ocelli, long in girdle view. Plastids discoid. The genus is probably one of the few which finds its ideal niche in brackish waters (estuaries, ditches, etc.), especially in tropical or subtropical regions. It can extend inland into waters of high salinity and will tolerate culture in seawater though it is not usually found in truly marine habitats. Valves circular (subcircular) with a flat valve face and deep mantles. Striae uniseriate, radiating from the centre and continuing without a break down the mantle; valve surface sometimes granulose. Areolae simple, penetrating a thick wall of silica; straight or enlarged slightly within the thickness of the valve framework - neither Ehrlich et al. (1982a) nor Compère (1982) could confidently detect a velum. Mantle edge recurved, sometimes fimbriate. Two ocelli, each surrounded by a distinct rim and bent over the junction between valve face and mantle, sometimes slightly raised but never on elevations. Rimoportulae present, lying in small clear areas, either off-centre in two groups along an axis at right angles to the axis between the ocelli (P. laevis), or in a circle (P. socotrensis); internally sessile, lying in depressions; externally with slit-like openings. Valvocopula split and fimbriate. Copulae split, fimbriate, ligulate, and anti-ligulate. All bands finely areolate.The most recent alteration to this page was made on 7 May 2015 by M.D. Guiry.
Comments: The genus Proteucylindrus Li & Chiang is considered synonymous (Compère, 1982). Cerataulus encompasses different species in which there is a twist in the axis between the ocelli. As mentioned in Ehrlich et al. (1982a), Pleurosira is the correct generic name for the diatom which has long been called Cerataulus laevis and Compère (1982) validated this - see these papers and Ehrlich et al. (1982a, b) for detail.
Numbers of names and species: There are 6 species names in the database at present, as well as 3 infraspecific names. Of the species names, 5 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.
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: 23 April 2002 by M.D. Guiry
Verified by: 07 May 2015 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=44186
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 15 December 2018.