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Spirogyra 3.jpg
Conjugation in Spirogyra.
Scientific classification

Round, 1971


  • Akontae Blackman & Tansley, 1902
  • Conjugatophyceae Engler, 1892
  • 'Conjugatae' Engler, 1892
  • Gamophyceae
  • Saccodermae Pascher ex Kossinskaja, 1952
  • Zygnemaphyceae Round 1971
  • Zygophyceae Widder, 1960

Zygnematophyceae (or Conjugatophyceae) is a class of green algae in the division Charophyta.[2] It contains the order Zygnematales. The Desmidiales emerged within the Zygnematales.[3] The Zygnematophyceae are the sister clade of the Mesotaenium, together forming the sister clade of the land plants.[4][5][6]

Sexual reproduction in the Zygnematophyceae takes place through a process called conjugation.[7] Here cells or filaments of opposite gender line up, and tubes form between corresponding cells. The male cells then become amoeboid and crawl across the female, or sometimes both cells crawl into the connecting tube. The cells then meet and fuse to form a zygote, which later undergoes meiosis to produce new cells or filaments. As in plants, only the female passes its chloroplasts on to the offspring.[citation needed]


  1. ^ Guiry, M.D. (2013). Taxonomy and nomenclature of the Conjugatophyceae (=Zygnematophyceae).[permanent dead link] Algae. An International Journal of Algal Research 28: 1-29.
  2. ^ Gontcharov AA, Marin B, Melkonian M (March 2004). "Are combined analyses better than single gene phylogenies? A case study using SSU rDNA and rbcL sequence comparisons in the Zygnematophyceae (Streptophyta)". Mol. Biol. Evol. 21 (3): 612–24. doi:10.1093/molbev/msh052. PMID 14739253.CS1 maint: Multiple names: authors list (link)
  3. ^ Lemieux, Claude; Otis, Christian; Turmel, Monique (2016). "Comparative Chloroplast Genome Analyses of Streptophyte Green Algae Uncover Major Structural Alterations in the Klebsormidiophyceae, Coleochaetophyceae and Zygnematophyceae". Frontiers in Plant Science. 7. doi:10.3389/fpls.2016.00697. ISSN 1664-462X. PMC 4877394.
  4. ^ Wickett, Norman J.; Mirarab, Siavash; Nguyen, Nam; Warnow, Tandy; Carpenter, Eric; Matasci, Naim; Ayyampalayam, Saravanaraj; Barker, Michael S.; Burleigh, J. Gordon (2014-11-11). "Phylotranscriptomic analysis of the origin and early diversification of land plants". Proceedings of the National Academy of Sciences. 111 (45): E4859–E4868. doi:10.1073/pnas.1323926111. ISSN 0027-8424. PMC 4234587. PMID 25355905.
  5. ^ de Vries, Jan; Stanton, Amanda; Archibald, John M.; Gould, Sven B. (2016-02-16). "Streptophyte Terrestrialization in Light of Plastid Evolution". Trends in Plant Science. 0 (0). doi:10.1016/j.tplants.2016.01.021. ISSN 1360-1385.
  6. ^ Gitzendanner, Matthew A.; Soltis, Pamela S.; Wong, Gane K.-S.; Ruhfel, Brad R.; Soltis, Douglas E. (2018). "Plastid phylogenomic analysis of green plants: A billion years of evolutionary history". American Journal of Botany. 105 (3): 291–301. doi:10.1002/ajb2.1048. ISSN 0002-9122.
  7. ^ Kapraun DF (April 2007). "Nuclear DNA Content Estimates in Green Algal Lineages: Chlorophyta and Streptophyta". Ann. Bot. 99 (4): 677–701. doi:10.1093/aob/mcl294. PMC 2802934. PMID 17272304.