Rhodomonas G.Karsten, 1898

Holotype species: Rhodomonas baltica Karsten

Original publication and holotype designation: Karsten, G. (1898). Rhodomonas baltica, n.g. et sp. Wissenschaftliche Meeresuntersuchungen, Abteilung Kiel, Neue Folge 3: 15-16.

Description: Free-swimming, generally ovoid, biflagellate monads; the furrow-gullet system consisting of a short furrow extending posteriorly from the vestibulum and transforming into a tubular gullet lined generally with two to four or more rows of ejectisomes; usually with one chloroplast, pyrenoid and nucleomorph, but in a few species these divide shortly after cell division so that there are two chloroplasts, p yrenoids and nucleomorphs for most of the cell cycle; the chloroplast has the phycobiliprotein Cr-phycoerythrin 545 and varies from red-brown to yellow and sometimes green in older cells; periplast with an inner layer of plates and a superficial layer of coarse fibrillar material sandwiching the plasma membrane. Reproduction by simple cell division. Palmelloid colonies are frequently formed and cell division often occurs in this state. Cysts and sexual reproduction are unknown. Typical cryptomonad ultrastructure. The inner periplast plates are roughly rectangular in shape with strong attachment sites to the plasma membrane along their posterior margins; they are organized in offset longitudinal rows. The nucleomorph is located in an invagination of the periplastidial compartment into the pyrenoid. The pyrenoidal matrix is not traversed by thylakoids. The fine structure of the thylakoids has been examined in some detail. Early reports on the fine structure of mitosis in the Cryptophyceae were with species of Rhodomonas. This genus has also, more recently, been used in a series of rather elegant experiments proving the presence of and localizing DNA in the nucleomorph. These experiments were facilitated by the location of the nucleomorph in the pyrenoidal matrix. Rhodomonas is cosmopolitan and common, although rarely abundant, in marine and brackish waters and two freshwater species are known from Europe. The genus is easy to recognize under the light microscope and the species easily cultured. Species of Rhodomonas have therefore often been the subject of research, although the name rarely appears in the literature due to a checkered taxonomic history. The name has often been overlooked due to the implication of color being of primary diagnostic importance. Other more important features have more recently indicated that Rhodomonas is indeed a natural assemblage of cryptomonads. Emend. Hill & Wetherbee (1989: 155) but see Novarino (1991).

Information contributed by: D.R.A. Hill. The most recent alteration to this page was made on 2017-05-26 by M.D. Guiry.

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

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.

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Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 26 May 2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 25 November 2024