Tychonema Anagnostidis & Komárek, 1988

Holotype species: Tychonema tenue (Skuja) K.Anagnostidis & J.Komárek

Original publication and holotype designation: Anagnostidis, K. & Komárek, J. (1988). Modern approach to the classification system of cyanophytes. 3. Oscillatoriales. Archiv für Hydrobiologie, Supplement 80(1-4): 327-472, 35 figs, 13 tables.

Description: Filamentous; filaments solitary, free floating or coiled in clusters or fine strata, planktonic, tychoplanktonic, benthic or metaphytic, straight, arcuated or freely irregularly coiled, many-celled, to 5 mm long, isopolar, without sheaths or facultatively with very fine and indistinct mucilaginous enveloping layers. Trichomes cylindrical, isopolar, not attenuated to the ends, unconstricted (or indistinctly constricted) at the crosswalls, more or less isodiametric or slightly longer or shorter than wide, with thin cell walls, 2-16 _m wide, without any branching, without or with reduced motility; end cells rounded, usually with thickened outer cell wall or with narrow calyptra. Cells mostly cylindrical, pale blue-green, yellowish or reddish, always without gas vesicles, but sometimes intensely vacuolated during prominent phases of vegetation cycles and with keritomized chromatoplasm (special location of thylakoids combined with vacuolization). Changeable phycobilin pigments ratio, usually with higher content of phycoerythrin. Heterocytes and akinetes absent. Cells divide by symmetric binary fission with very different division frequencies on a trichome and during the vegetation phase; all cells capable of division. Reproduction by fragmentation of trichomes into non-motile hormocytes.Planktonic, tychoplanktonic or benthic species, known mainly from northern European, oligotrophic, mesotrophic or slightly eutrophic reservoirs. Probably mainly cold-stenothermal species, distributed in colder parts of temperate zone.

Information contributed by: J. Komárek. The most recent alteration to this page was made on 2023-03-03 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 neuter.

Most recent taxonomic treatment adopted: Komárek, J., Kaštovský, J., Mares, J. & Johansen, J.R. (2014). Taxonomic classification of cyanoprokaryotes (cyanobacterial genera) 2014, using a polyphasic approach. Preslia 86: 295-335.

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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=43611

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 03 March 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 29 March 2024

 
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