Ophiocytium Nägeli, 1849, nom. cons.

Holotype species: Ophiocytium apiculatum Nägeli

Original publication and holotype designation: Nägeli, C. (1849). Gattungen einzelliger Algen, physiologisch und systematisch bearbeitet. Neue Denkschriften der Allg. Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften 10(7): i-viii, 1-139, pls I-VIII.

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Description: Unicellular or colonial, free-living or attached organisms 9-2500 µm long and 2-27 µm wide. Colonies dendroid. Cells cylindrical, elongated, straight, spiralled, sigmoid or semi-circular, sometimes swollen and with rounded extremities, with or without spine (3-15 µm long) or pedicel (3-35 µm long). When present, pedicel frequently terminated by a brownish disk which attaches organism to substratum. Cell wall thin or thick, strong and sometimes brown, formed in two unequal portions. The basal portion is tubular and elongates along with the cell; the second portion at the free apex of the cell has a constant size. Young cells always uninucleate, becoming multinucleate with age. Chloroplasts (single to numerous) discoid, stellate, ribbon-shaped or H-shaped in optical section, parietal and green, yellow green or blue green. Pyrenoids absent. Cytoplasm with numerous oil or dark red lipid globules. Asexual reproduction by zoosporulation or autosporulation. Zoospores with two unequal flagella, two chloroplasts and, without doubt, no stigma, formed in twos or fours in each mother cell. Zoospores released by a raising of the apcial cell wall piece. After a short swimming period , they attach to the edge of the basal cell wall portion and develop into new vegetative cells, thus forming a dendroid colony. Autospores liberated similar to zoospores. Thick-walled cysts also produced.

Information contributed by: H.R. Preisig & I.M. Franceschini. The most recent alteration to this page was made on 2021-10-05 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 neuter.

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.

Comments: Ophiocytium species are planktonic, tychoplanktonic or epiphytic on filamentous algae in freshwater; cosmopolitan. Species are distinguished based on the free-living or attached nature of the organism, whether it is free-living or attached. Colony morphology, cell diameter, presence or absence and length and morphology of apical spines and pedicel and symmetry (or lack of) of the poles are also important specific characters.

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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=43831

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 05 October 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024