Zygnemopsis (Skuja) Transeau, 1934
Lectotype species: Zygnemopsis reticulata (Hallas) Transeau
Original publication: Transeau, E.N. (1934). The Genera of the Zygnemataceae. Transactions of the American Microscopical Society LVII [53]: 201-207.
Type designated in: Transeau, E.N., Tiffany, L.H., Taft, C.E. & Li, L.C. (1934). New species of Zygnemataceae. Transactions of the American Microscopical Society 53(3): 208-230, plates 17-22.
Request PDFDescription: Thalli comprised of unbranched uniseriate filaments, intertwined to form skeins. Cells 5-50 µm in diameter, several times as wide; cell wall two-layered with inner cellulose, outer mucilage layer; end walls plane; no flagellated stages. Vegetatively indistinguishable from Zygnema. Cell uninucleate; chloroplasts two per cell with radiating short branches (stellate); single large pyrenoid in center of each. Asexual reproduction by parthenospores and akinetes in some species, aplanospores lacking. Sexual reproduction part of a haplobiontic life cycle with zygotic meiosis and scalariform conjugation. At start of conjugation part of cell contents replaced by layers of pectic transparent refractive gel; these layers push passive gametes into conjugation tube. Conjugation tube initially narrow, later enlarged when zygospore forms within. Mature zygospores vary in shape from ellipsoid-ovoid to quadrangular, the latter resembling those of Mougeotia. Zygospores contained within outer wall; four rigid, lamellate projections at corners. Median wall (mesospore) smooth or ornamented. Zygnemopsis broadly distributed: North America, Asia, Europe, Africa; uncommon compared to Spirogyra, Mougeotia and Zygnema. T
Information contributed by: R.M. McCourt and R.W. Hoshaw. The most recent alteration to this page was made on 2022-09-26 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Gender: This genus name is currently treated as feminine.
Most recent taxonomic treatment adopted: Hess, S., Williams, S.K., Busch, A., Irisarri, I., Delwiche, C.F., de Vries, S., Darienko, T., Roger, A.J., Archibald, J.M., Buschmann, H., von Schwartzenberg, K. & de Vries, J. (2022). A phylogenomically informed five-order system for the closest relatives of land plants. Current Biology 32: 1-10.
Comments: Zygnemopsis species are widely distributed: North America, Asia, Europe, Africa, but are uncommon compared to species of Spirogyra, Mougeotia and Zygnema.
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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=43567
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 26 September 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 16 April 2024
