Acanthosphaera Lemmermann, 1899
Holotype species: Acanthosphaera zachariasii Lemmermann
Original publication and holotype designation: Lemmermann, E. (1899). Das Phytoplankton sächsischer Teiche. Forschungsberichte aus der Biologischen Station zu Plön 7: 96-135, pls I, II.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Tsarenko, P.M. (2011). Trebouxiophyceae. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 61-108. Ruggell: A.R.A. Gantner Verlag K.-G..
Description: Unicellular algae with spherical cells 8-15 &m diameter with 20-40 radially arranged spines. Spines 20-70 &m in length, pointed at tips with expanded conical, hollow base. Cells uninucleate; single chloroplast parietal and cup-shaped; single pyrenoid prominent with distinct starch sheath and with numerous, finger-like cytoplasmic extensions. Asexual reproduction by biflagellate zoospores, 2, 4 or 8 per sporangium; released by rupture of parental wall in common membrane. Zoospores ovoid often with 2 stigmata and four contractile vacuoles. Sexual reproduction unknown. Acanthosphaera planktonic in freshwater ponds and lakes; essentially cosmopolitan with records from Europe, Asia and North America, mostly in temperate climates. Type species widely distributed, but A. tenuispina known only from Charkov in former USSR. Ultrastructural and chemical studies of spines and cell wall show complex construction with specialized arrangement of fibrils, 3-4 nm subfibrils, 200-300 nm long spicules on the spines. Spines consist mostly of stiff, parallel, non-crossbanded fibrils. Spines form on incompletely developed cell walls but only after glycoproteidic outer layer deposited. Species distinguished based on cell size, and spine length and morphology. Relationships of genus within family will require further ultrastructural studies.
Information contributed by: D. Garbary. The most recent alteration to this page was made on 20 Dec 2011 by M.D. Guiry.
Numbers of names and species: There are 2 species names in the database at present, of which 1 has 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.
Cambra Sánchez, J., Álvarez Cobelas, M. & Aboal Sanjurjo, M. (1998). Lista florística y bibliográfica de los clorófitos (Chlorophyta) de la Península Ibérica, Islas Baleares e Islas Canarias. pp. 1-614. Burgos: Asociación Española de Limnología.
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: 08 March 2003 by M.D. Guiry
Verified by: 20 December 2011 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=45037
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 October 2018.