Scytomonas F.Stein, 1878

Holotype species: Scytomonas pusilla 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.

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Description: Colorless, phagotrophic or coprophilous saprophytes, or intestinal (?) parasites; unique among euglenoids in having only a single flagellum (no reduced second flagellum in the reservoir); therefore separated from Petalomonadaceae; no ingestion organelle visible in the light microscope but electron microscopy reveals a simple feeding pocket with microtubules, as found in Petalomonas; cells 7-15 _m long, pyriform, not flattened, rigid; EM shows periplast to consist of 5 strips. Also unique in being the only euglenoid where sexuality is known (Dobell, 1908); 2 cells act as isogametes and fuse; one flagellum is lost and the zygote swims by means of the other; the gamete nuclei fuse (Mignot, 1961) but meiosis and further stages have not been seen. Freshwater and estuarine; Europe, Asia and the Americas. Colorless, phagotrophic or coprophilous saprophytes, or intestinal (?) parasites; unique among euglenoids in having only a single flagellum (no reduced second flagellum in the reservoir); therefore separated from Petalomonadaceae; no ingestion organelle visible in the light microscope but electron microscopy reveals a simple feeding pocket with microtubules, as found in Petalomonas; cells 7-15 _m long, pyriform, not flattened, rigid; EM shows periplast to consist of 5 strips. Also unique in being the only euglenoid where sexuality is known (Dobell, 1908); 2 cells act as isogametes and fuse; one flagellum is lost and the zygote swims by means of the other; the gamete nuclei fuse (Mignot, 1961) but meiosis and further stages have not been seen. Freshwater and estuarine; Europe, Asia and the Americas.

Information contributed by: G.F. Leedale. The most recent alteration to this page was made on 2023-12-16 by E.A. Molinari Novoa.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Gender: This genus name is currently treated as feminine.

Most recent taxonomic treatment adopted: Cavalier-Smith, T. (2016). Higher classification and phylogeny of Euglenozoa. European Journal of Protistology 56: 250–276, 2 figs.

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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=46212

Citing AlgaeBase
Cite this record as:
E.A. Molinari Novoa in Guiry, M.D. & Guiry, G.M. 16 December 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 16 April 2024