Ornithocercus Stein, 1883
Holotype species: Ornithocercus magnificus F.Stein
Original publication and holotype designation: Stein, F. von (1883). Der Organismus der Infusionsthiere nach eigenen forschungen in systematischere Reihenfolge bearbeitet. III. Abtheilung. II. Hälfte die Naturgeschichte der Arthrodelen Flagellaten. pp. 1-30, pls I-XXV. Leipzig: Verlag von Wilhelm Engelmann.
Taxonomic status: currently recognized as a distinct genus.
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. 11-189. Stuttgart: Borntraeger Science Publishers.
Description: Medium-sized (30-80 µm) laterally compressed flagellate of subcircular, obovate or subtrapeziform in lateral view with characteristic elaborate wings and lists. Very broad cingular lists with many ribs but usually without cross-ribs, in few species with elaborate reticulation between the ribs, separate the reduced epicone from the large hypocone. Right sulcal list usually small, whereas the left sulcal lists are large, extending to the antapex. The small left hypothecal plate bears a list which may extend to the dorsal side of the hypothecal cingular list. These lists have ribs and may have a reticulation. The theca is similar to Dinophysis but apparently has one plate less in the apical region of the ventral apical pore, resulting in only 5 epithecal plates. There are 4 cingular, 4 sulcal, and 4 hypothecal plates as in most other genera of the Dinophysiales. In contrast to Dinophysis, the "ventral" small hypothecal plates are much more elongated, extending to the dorsal side. Nucleus located in the hypocone; chloroplasts absent, food vacuoles present so nutrition is apparently phagotrophic. On the lists and wings, in particular in between the collar-like cingular lists, always present are phaesomes, namely blue-greens of the genus Synechococcus. The exact relationship between these 2 partners is so far unknown. Division is by binary fission in the motile stage, each daughter cell receiving part of the mother theca. Sexual reproduction and cyst formation not known. Marine oceanic plankton, in tropical and subtropical waters of all oceans
Information contributed by: M. Elbrächter. The most recent alteration to this page was made on 24 May 2017 by M.D. Guiry.
Numbers of names and species: There are 25 species names in the database at present, as well as 7 infraspecific names. Of the species names, 18 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Click here to also show infraspecific names in the list below.
Handy, S.M., Bachvaroff, T.R., Timme, R.E., Coats, D.W., Kim, S. & Delwiche, C.F. (2009). Phylogeny of four dinophysiacean genera (Dinophyceae, Dinophysiales) based on rDNA sequences from single cells and environmental samples. Journal of Phycology 45(5): 1163-1174.
Hastrup Jensen, M. & Daugbjerg, N. (2009). Molecular phylogeny of selected species of the order Dinophysiales (Dinophyceae) - testing the hypothesis of a dinophysioid radiation. Journal of Phycology 45(5): 1136-1152.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 07 May 2002 by M.D. Guiry
Verified by: 24 May 2017 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=44663
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 26 October 2020.