Hafniomonas Ettl & Moestrup, 1980

Holotype species: Hafniomonas reticulata (Korshikov) Ettl & Moestrup

Original publication and holotype designation: Ettl, H. & Moestrup, Ø. (1980). Light and electron microscopical studies on Hafniomonas gen. nov. (Chlorophyceae, Volvocales), a genus resembling Pyramimonas. Plant Systematics and Evolution 135: 177-210.

Description: Unicellular,quadriflagellate and uninucleate algae without cellulosic cell walls.Cells elongate- to short-cylindric, ovoid, pyriform or, less often,ellipsoid-globose to cordate, occasionally with some degree of metaboly.In cross-sectional view, cells quadrangular with later margins entire orretuse, sometimes with angles extended into broadly roundedprotuberances. Posterior end usually broadly rounded to rounded-truncate;anterior end bearing four longitudinally disposed, rounded periplast ridgesthat do not extent to base of cell. Anterior end with four flagellaarising from slight depression often placed slightly below origin of periplastridges; in some cases with a small apical papilla. Chloroplast parietaland principally cup-shaped with a distinct stigma and a pyrenoid that isvariable in position. In some species chloroplast perforate, breakingdown into numerous individual segments. Nucleus and two contractilevacuoles in anterior of cell.Asexualreproduction by cell division, sometimes giving rise to palmelloid stage.Occasionally cells become encysted; cysts with smooth or scrobiculatewalls. Sexual reproduction unknown.

Information contributed by: G.E. Dillard. The most recent alteration to this page was made on 2012-01-23 by M.D. Guiry.

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

Most recent taxonomic treatment adopted: Pentecost, A. (2002). Order Volvocales. In: The Freshwater Algal Flora of the British Isles. An identification guide to freshwater and terrestrial algae. (John, D.M., Whitton, B.A. & Brook, A.J. Eds), pp. 303-327. Cambridge: Cambridge University Press.

Comments: Hafniomonas> from freshwater, reported from Germany, GreatBritain, Austria, USSR and Czechoslovakia.Elevenspecies well decribed, all previously placed in Pyramimonas.Species differentiated on presence or absence of pyrenoids, relative positionof pyrenoid in cell, size of stigma, form of chloroplast, and shape anddimensions of cell.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=44228

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 23 January 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 18 December 2024