Trichodesmium Ehrenberg ex Gomont, 1892, nom. cons.
Lectotype species: Trichodesmium erythraeum Ehrenberg ex Gomont
Original publication: Gomont, M. (1892 '1893'). Monographie des Oscillariées (Nostocacées Homocystées). Deuxième partie. - Lyngbyées. Annales des Sciences Naturelles, Botanique, Série 7 16: 91-264, pls 1-7.
Request PDFType designated in: Geitler, L. (1942). Schizophyta: Klasse Schizophyceae. In: Die natürlichen Pflanzenfamilien, Sweite Auflage. (Engler, A. & Prantl, K. Eds) Vol.1b, pp. 1-232. Leipzig: Wilhelm Engelmann.
Description: Filamentous-colonial; trichomes straight or curved, free-floating, unified parallel into fascicles or radially into elongated or spherical, small colonies by the help of fine, unstructured, diffluent, colorless, homogeneous mucilage. Trichomes slightly motile, 6-22 _m wide, at the ends sometimes attenuated to conspicuously attenuated with elongated and hyaline terminal cells, or not attenuated, only with a rounded or narrowed terminal cell, sometimes with a calyptra, constricted or unconstricted at the crosswalls, multicelled, simple, uniseriate, unbranched, without firm sheaths. Cells more or less isodiametric or slightly shorter or longer than wide, cylindrical or barrel-shaped, to the ends sometimes elongated, with plenty of aerotopes; thylakoids are irregularly coiled near the cell walls to through the whole cell content. In Trichodesmium species were found special ecophysiological properties (valid only for marine species ?), e.g., the special type of "strong" gas vesicles, capacity for nitrogen fixation, low molecular weight of fatty acid composition. Heterocytes and akinetes absent. Cell division by the crosswise fission of all cells, with exception of apical ones. The cells grow into original size before the next division. Reproduction by fragmentation of trichomes into motile hormogonia by help of necridic cells and by dissociation of colonies. Hormogonia germinate at both ends (isopolar). Strictly planktonic species, from which three are freshwater (rarely occurring in large reservoirs), the other are marine. They cause sometimes reddish water blooms in tropical seas and oceans, sometimes in lower layers (several meters under the water level).
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: Tanaka, T. (1952). The systematic study of the Japanese Protoflorideae. Memoirs of the Faculty of Fisheries, Kagoshima University 2(2): 1-92, 41 figs, 23 pls.
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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=43303
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 22 November 2024
