Oocardium Nägeli, 1849
Holotype species: Oocardium stratum Nägeli
Original publication and holotype designation: Nägeli, C. (1849). Gattungen einzelliger Algen, physiologisch und systematisch bearbeitet. Neue Denkschriften der Allg. Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften 10(7): i-viii, 1-139, pls I-VIII.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Guiry, M.D. (2013). Taxonomy and nomenclature of the Conjugatophyceae (=Zygnematophyceae). Algae. An International Journal of Algal Research 28: 1-29.
This name also appeared in Kützing (1849: 196), where it is attributed to Nägeli; this may be the first publication of the name. - (2 Apr 2011) - M.D. Guiry
Description: Cells small (length 7-20 µm), in macroscopic (1-2 mm) colonies attached to solid substrata. Cells usually laterally asymmetrical, slightly compressed, with shallow median constriction (isthmus) where semicell walls overlap. Cells at ends of branched gelatinous stalks within encrusting calcareous tubes. Cell axis always at right angle to axis of tube (often incorrectly illustrated). Cell walls smooth, of two parts which overlap at median constriction. Usually one axial chloroplast with central pyrenoid per semicell (sometimes pressed to one side of semicell). Nucleus in isthmus between chloroplasts. Asexual reproduction by typical Cosmarium-type desmid cell division and new semicell formation (see Cosmarium). Sexual reproduction by conjugation, forming irregularly quadrangular zygospores with several mamillate projections to which empty gametangial walls remain attached.
Information contributed by: J.F. Gerrath. The most recent alteration to this page was made on 12 Sep 2013 by M.D. Guiry.
Comments: Rare, reported from streams in limestone areas of Europe, North America, and India. Colonies attached to stones, twigs, leaves, mosses, and feathers in calcium-rich streams (pH 7.5-9.3).
Numbers of names and species: There are 2 species names in the database at present, as well as 3 infraspecific names. Of the species names, 2 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: 16 April 2003 by M.D. Guiry
Verified by: 12 September 2013 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=45917
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 18 January 2019.