Oscillatoria Vaucher ex Gomont, 1892
Lectotype species: Oscillatoria princeps Vaucher 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.
Type designated in Gardner, N.L. (1932). The Myxophyceae of Porto Rico and the Virgin Islands. In: Scientific Survey of Porto Rico and the Virgin Islands. Volume VIII. Part 2. (Anon. Eds), pp. 249-311. New York: New York Academy of Sciences.
Precise date of publication1 Jan 1892
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Mühlsteinová, R., Hauer, T., De Lay, P. & Pietrasiak, N. (2018). Seeking the true Oscillatoria: a quest for a reliable phylogenetic and taxonomic reference point. Preslia (Prague) 90: 151-169, 4 figs.
Description: Trichomes blue- green to brownish-green, occasionally purple when old, highly motile, not or slightly constricted at the cross-walls, sometimes narrowing toward the often bent ends, central section of trichomes (19) 22-80 µm wide. Apical cells rounded and sometimes yellowish (together with several adjacent cells). Granulation never located at the cross-walls, but fine to large granules may be present in the cells. Cells much shorter than wide, new cell walls forming perpendicularly to the trichome axis, often before the previous division is finished. Cell wall colourless and thick, necridic cells present, sheath observed only in culture under stress conditions. No calyptra observed.
Information contributed by: Mühlsteinová <i>et al.</i> 2018. The most recent alteration to this page was made on 27 Nov 2018 by M.D. Guiry.
Comments: Blue-green mats form on the bottom of lakes, ponds, and maybe rivers, later in the season they release and float at the water surface. The genus is probably distributed worldwide outside of cold regions. The whole genus seems to be well characterized by presence of large pores perforating its thick cell wall. These pores are conspicuous under both TEM and SEM and in some of the very large representatives with trichomes above 40 ?m, their presence can be detected also by the means of light microscopy; when focused on the very surface of the filament, the cell wall has an appearance that is slightly reminescent of a snakeskin. We were not always able to observe the “snakeskin effect” in the light microscope on all the representatives that we had available, but even for the thinner specimen the pores were clearly visible in the electron microscope. The phylogenetic position of the genus is based on the newly designated epitype CBFS A-89-1 originating from the strain O. princeps CCALA 1115. The phylogenetic placement of the genus Oscillatoria in the order Oscillatoriales and its rela- tionship to other cyanobacteria included in its close proximity is shown in Fig. 5. Whereas the phylogenetic support for the genus itself is steadily high across all the analy- ses that were performed, its relationship to other simple trichal genera remains unclear. Within the analysed data available (2018), the genus stands alone with no evident sister group.
Numbers of names and species: There are 632 species names in the database at present, as well as 344 infraspecific names. Of the species names, 307 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
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Verification of data
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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.
Created: 28 December 2000 by M.D. Guiry
Verified by: 27 November 2018 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43083
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 13 December 2018.