Planctococcus Korshikov, 1953

Holotype species: Planctococcus sphaerocystiformis Korshikov

Original publication and holotype designation: Korshikov, A.A. (1953). Viznachnik prisnovodnihk vodorostey Ukrainsykoi RSR. Pidklas Protokokovi (Protococcineae). Bakuol'ni (Vacuolales) ta Protokokovi (Protococcales) [The Freshwater Algae of the Ukrainian SSR. Sub-Class Protococcineae. Vacuolales and Protococcales]. Vol. 5 pp. 439, 421 figures. Kyiv: Akademyy Nauk Ukrayins'koy RSR. [in Ukrainian]

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Description: Spherical colonial thalli to 70 µmdiameter consisting of 4-8 (-16) loosely packed spherical cells, 10-20 µmdiameter, enclosed in a conspicuous, colorless, and structureless mucilage. Cell wall colorless and smooth, initially thin but becoming thick with age. Cells uninucleate; chloroplast single and parietal, net-like and perforate, without pyrenoid. Asexual reproduction by autospores and zoospores. 16-32 autospores per mother cell, during sporulation mother cell wall thickens (up to 5 &m) and breaks open as a result of autospore expansion. After spore release mother cell wall remains intact as a single unit. Zoospores to 13 µmlong, oval to egg shaped and naked, 2-4 per mother cell and biflagellate. Zoospores with stigma and contractile vacuole. Sexual reproduction not described. However, based on presence of quadriflagellate, binucleate, cells (planozygotes?) with two stigmata, sex presumably occurs. Planctococcus planktonic in freshwater, reported from ponds and lakes in eastern and northern Europe. Genus included in Sphaerocystis by Bourrelly, however genera distinguished by later authors based on chloroplast morphology and presence or absence of pyrenoids.

Information contributed by: D. Garbary. The most recent alteration to this page was made on 2014-09-02 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Tsarenko, P.M. (2011). Chlorococcales. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 232-264. Ruggell: A.R.A. Gantner Verlag K.-G..

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=47443

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 02 September 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 28 April 2024