Tetraselmis F.Stein, 1878
Holotype species: Tetraselmis cordiformis (H.J.Carter) F.Stein
Original publication and holotype designation: Stein, F. von (1878). Der Organismus der Infusionsthiere nach eigenen forschungen in systematischere Reihenfolge bearbeitet. III. Abtheilung. Die Naturgeschichte der Flagellaten oder Geisselinfusorien. I. Hälfte, Den noch nicht abgeschlossenen allgemeinen Theil nebst erklärung: Der sämmtlichen Abbildungen enthaltend. pp. i-x, 1-154, pls I-XXIV. Leipzig: Verlag von Wilhelm Engelmann.
Request PDFDescription: Unicellular flagellates. Cells more or less compressed, often slightly curved but never twisted. Cells cordiform, elliptical or almost spherical. Anterior end with invagination, 4 equal flagella in 2 opposite pairs. The cell contains a single more or less cup-shaped chloroplast (very rarely two chloroplasts), usually with a central pyrenoid. A single eyespot is present, located on one of the flattened sides of the cell, the position depending on the species. Freshwater species contain two anterior contractile vacuoles. Cell surrounded by close-fitting periplast of fused scales. The flagella covered by square/diamond-shaped scales in 24 rows overlaid by 24 double rows of scales. Two rows of hair-shaped scales project from opposite sides of the flagella. Asexual division in the non-motile stage. In many species one of the daughter cells inverts within the parent periplast, the 2 daughter cells then lie in reversed positions. In the non-motile stage new walls develop, old walls accumulating as concentric rings around the cell or being polarized on one side, forming a stalk. The stalks may be long and occasionally branched. Sexual reproduction unknown. Vegetative thick walled cysts known in several species. These germinate by division into 4 cells. The species differ in cell shape, size, presence or absence of pyrenoids, chloroplast morphology, etc., but many of these features have been poorly described and the taxonomy of the genus is in a state of confusion. More recently the ultrastructure of the pyrenoid has been suggested as a taxonomic marker (Hori and others 1982) and, more recently, the detailed structure of the flagellar hair scales (Marin and others 1993). Some species of Tetraselmis occur in plankton, others are benthic, colonizing sand and a few occur as endosymbionts in metazoans, e.g. in the acoel turbellarian Convoluta (Provasoli and others 1968; Yamasu 1982). Mitosis described ultrastructurally by Stewart and others (1974), the flagellar apparatus by Norris and others (1980) and Melkonian (1978). Species of Tetraselmis have been used extensively in plant physiology and aquaculture (e.g. Gooday 1970; Kirst 1977; Douglas 1983; Regan 1988; Day and Turner 1992).
Information contributed by: Ø. Moestrup. The most recent alteration to this page was made on 2021-08-23 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Moestrup, Ø. (2002). Phylum Prasinophyta. In: The Freshwater Algal Flora of the British Isles. An identification guide to freshwater and terrestrial algae. (John, D.M., Whitton, B.A. & Brook, A.J. Eds), pp. 281-286. Cambridge: Cambridge University Press.
Comments: Throndsen (1997: 654) records this genus as a member of the Phylum Chromophyta, Class Prasinophyceae, Order Chlorodendrales, Family Chlorodendraceae.
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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.
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Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 23 August 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 November 2024
