Phacomonas Lohmann, 1903
Holotype species: Phacomonas pelagica Lohmann
Original publication and holotype designation: Lohmann, H. (1902 '1903'). Neue Untersuchungen über den Reichthum des Meeres an Plankton und über die Brauchbarkeit der verschiedenen Fangmethoden. Zugleich auch ein Beitrag zur Kenntnis des Mittelmeerauftriebs. Wissenschaftliche Meeresuntersuchungen, Abteilung Kiel, Neue Folge 7: 1-87.
Request PDFDescription: Unicellular, solitary, free-living organisms 5-10 _m long. Cells with graceful movement by means of two unequal flagella longer than the cell body and each inserted on a small nipple, one at the apex, the other lateral. Cells, without cell walls, with a coarsely discoid form with the diameter about three times the thickness. In face view cells circular to ellipsoidal; in profile cells elliptical to slightly biconvex. Chloroplasts two per cell, discoid, and parietal, asymmetrically arranged here and there along the anterior-posterior axis and opposite each other. Stigma and pyrenoid absent. Cells mostly with a strongly refringent globule with well defined outline in the basal region; cells also with oil granules and lipids. The freshwater species has two contractile vacuoles. Vegetative reproduction, cyst formation or palmelloid stages have never been observed. Phacomonas uncommon, known from the Atlantic Ocean and marshes of central Europe. . lacustris Van Oye has a thick cell wall with two flagella inserted at the base of a single apical papillae; it fits into the genus as circumscribed by Pascher. Species distinguished based on ecology (freshwater or marine), and the presence of contractile vacuoles in the freshwater organisms.
Information contributed by: C. Cardinal-Legrand. The most recent alteration to this page was made on 2021-10-03 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 feminine.
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=45995
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 03 October 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 27 April 2024
