Pseudosphaerocystis Woronichin, 1931

Holotype species: Pseudosphaerocystis lacustris (Lemmermann) Nováková

Description: Spherical to amorphous colonial thalli to 200 µm diameter with up to 64 or 128 cells embedded in thick, mucilaginous, hyaline and structureless envelope. Cuboid packets (i.e. not tetrahedral) of four cells, or larger, more irregular groups dispersed in matrix. Cells ellipsoid to spherical, 7-10 x 8-12 µm, often wider than long, and often in pairs with anterior ends facing. Cell walls thin and smooth. Cells uninucleate with two anterior contractile vacuoles; single chloroplast parietal and cup shaped, stellate in P. neglecta, with ellipsoidal basal pyrenoid surrounded with starch sheath; stigma in zoospores and often in vegetative cells. Asexual reproduction by autospores or zoospores and colony fragmentation. Zoospores same size as vegetative cells and spherical to pear shaped without apical papilla. Sexual reproduction unknown. Pseudosphaerocystis planktonic in freshwater ponds and lakes; two verified species in genus reported only from Europe with third (uncertain) species known only from India. Species distinguished based on details of chloroplast and pyrenoid morphology. P. indica described from Madras regarded as uncertain member of genus by Ettl & Gärtner (1988).

Information contributed by: D. Garbary & A. Couté. The most recent alteration to this page was made on 2012-06-29 by Michael Guiry.

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

Most recent taxonomic treatment adopted: Masjuk, N.P. & Lilitska, G.G. (2011). Volvocales. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 218-225. 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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=44239

Citing AlgaeBase
Cite this record as:
Michael Guiry in Guiry, M.D. & Guiry, G.M. 29 June 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 23 November 2024