Hermesinum O.Zacharias, 1906

Holotype species: Hermesinum adriaticum Zacharias

Original publication and holotype designation: Zacharias, O. (1906). Eine neue dictyochide aus dem Mittelmeer, Hermesinum adriaticum n.g., n. sp.. Archiv für Hydrobiologie und Planktonkunde 1: 394-98, Figs. a-d.

Fossil: This is a genus of fossil species, or a genus with a fossil type species, or a genus the type species of which was originally described as a fossil.

Description: Unicellular biflagellate with unequal flagella subapically inserted, lacking chloroplasts but often with endosymbiotic Synechococcus-like cyanobacteria. Cells approximately rhomboid, surrounding an internal silica skeleton composed of solid elements which partly enclose the nucleus. Skeleton consists of a framework of narrow rugose or spiny rods which are basically tetraxial in arrangement (triaene),, and whose complex nomenclature is based on that of sponge spicules: an axial shaft (rhabde) elongated anteriorly and posteriorly, with primary (actines) and secondary (clades) branches. Nucleus contains condensed chromatin (but not homologous to dinoflagellate nuclei), giving it a granular appearance; mitochondria with tubular cristae; cell wall lacking. Cells pale yellow-green, 30-50 &m long, 20-30 &m wide; motion is apically directed and wobbly. Cell division is apparently asexual with duplication of skeleton before separation; sexual stages and cysts unknown. Widespread in coastal temperate and tropical waters of >22%C and 15-30 ppt salinity; not usually abundant, but occasionally 10⁵/liter. Nutrition is primarily bacterivorous. Classification as algae is problematical.

Information contributed by: P. Hargraves. The most recent alteration to this page was made on 2023-01-25 by E.A. Molinari Novoa.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Sournia, A. (1986). Atlas du phytoplancton marin. Volume I: Cyanophycées, Dictyophycées, Dinophycées, Raphidophycées. pp. [1]-219. Paris: Éditions du Centre National de la Recherche Scientifique 15, quai Anatole France - 75700 Paris.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=45630

Citing AlgaeBase
Cite this record as:
E.A. Molinari Novoa in Guiry, M.D. & Guiry, G.M. 25 January 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 04 May 2024