Chrysoxys Skuja, 1948
Lectotype species: Chrysoxys maior Skuja
Original publication: Skuja, H. (1948). Taxonomie des Phytoplanktons einiger Seen in Uppland, Schweden. Symbolae Botanicae Upsalienses 9(3): 1-399, 39 pls.
Type designated in: Bourrelly, P. (1957). Recherches sur les Chrysophycées. Morphologie, phylogénie, systématique. Mémoire Hors-Série Revue Algologique 1: [1]-412, incl. 11 pls.
Request PDFDescription: Colonies variable in size, up to 0.5 mm long, consisting of up to 100 cells. Cells arranged rather loosely within a finely structured gelatinous matrix, usually radiating in an irregular way from a central axis and forming irregularly lobed thalli. Cells are metabolic, elongate obovate to spindle-shaped or sometimes slightly curved, sitting in narrow cavities of the gelatinous matrix. They are attached by a contractile rhizopodial stalk emerging from the base of the cell. At the obliquely truncate anterior end of the cell there are often 2 unequal flagella; sometimes flagella are lacking and, instead, there is one or more thread-like rhizopodia, which may be branched. Protoplast with 1-2 parietal chloroplasts, stigma present or lacking, and 2 contractile vacuoles in a subequatorial position. Cell division apparently by oblique transverse fission of the cell, but reproduction has not been observed in detail. Stomatocysts known, but sexual reproduction not observed. Reported from Europe and USA. Found in freshwater, free-swimming or epiphytic (e.g. on Typha or in the mucilage of planktonic Cyanobacteria like Coelosphaerium). Skuja (1948) suggested this genus belonged to the Dinobryaceae since the individual cells were located within cavities which resembled loricas in outline and, in his opinion, the gelatinous matrix of the colony was formed by gelatinization of the outer layers of the loricas. According to Bourrelly (1957, 1981), this genus belongs in the Chromulinaceae (Ochromonadaceae) since there are no distinct loricas.
Information contributed by: H. R. Preisig. The most recent alteration to this page was made on 2021-10-11 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Kristiansen, J. & Preisig, H.R. (2001). Encyclopedia of Chrysophyte genera. Bibliotheca Phycologica 110: 1-260.
Comments: Kristiansen & Preisig (2001: 9) record this genus as alternately being a member of the family Ochromonadaceae Lemmerman 1899.
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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=44723
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 11 October 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 19 April 2024
