Dioxys Pascher, 1932
Holotype species: Dioxys incus Pascher
Original publication: Pascher, A. (1932). Über einige neue oder kritische Heterokonten. (Beiträge zur Kenntnis der einheimischen Algenflora. II.). Archiv für Protistenkunde 77: 305-359.
Type designated in: Loeblich, A.R., III (1967). Nomenclatural notes in the Pyrrhophyta, Xanthophyta and Euglenophyta. Taxon 16(1): 68-69, no figs.
Request PDFDescription: Unicellular, solitary organisms always attached to substratum by a pedicel 4-12 _m long. Cells 3.5 to 25 _m high and 4-20 _m wide, irregularly fusiform to polygonal and with the large axis either parallel or perpendicular to the substratum. Sometimes, especially in triangular or truncated-cone shaped cells, the poles have pointed prolongations to greater or lesser extents. One species is especially spiny. Chloroplasts single to numerous, discoid to lamellate, parietal and yellow green. Stigma and contractile vacuole observed in young cells. Cytoplasm with numerous refringent granules and red oil droplets. Asexual reproduction by zoosporulation. Zoospores ovoid with two very unequal flagella and with one to many chloroplasts. Spherical to ovoid aplanospores, probably with a cell wall in two sections, formed in large numbers in some species. Dioxys rarely reported, attached to algae or aquatic plants, in lakes or ponds and in brackish or eutrophic conditions; known from central and northern Europe, North and South America and east Africa. Species distinguished based on the form and dimensions of cells and on the number and dimensions of apical thickenings or horns. Dioxys wurtzii Bourrelly considered by Ettl (1978) as a chlorophycean relative of Bicuspidellopsis Korschikoff is maintained in the Tribophyceae by Tell and Pizarro (1983).
Information contributed by: G. Tell. The most recent alteration to this page was made on 2022-12-20 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 masculine.
Most recent taxonomic treatment adopted: Kawai, H. & Nakayama, T. (2015). Introduction (Heterokontobionta p.p.), Cryptophyta, Dinophyta, Haptophyta, Heterokontophyta (except Coscinodiscophyceae, Mediophyceae, Fragilariophyceae, Bacillariophyceae, Phaeophyceae, Eustigmatophyceae), Chlorarachniophyta, Euglenophyta. In: Syllabus of plant families. Adolf Engler's Syllabus der Pflanzenfamilien. Ed. 13. Phototrophic eukaryotic Algae. Glaucocystophyta, Cryptophyta, Dinophyta/Dinozoa, Haptophyta, Heterokontophyta/Ochrophyta, Chlorarachnniophyta/Cercozoa, Chlorophyta, Streptophyta p.p. (Frey, W. Eds), pp. 11-64, 103-139. Stuttgart: Borntraeger Science Publishers.
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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=45425
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 20 December 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 25 April 2024
