Guillardia D.R.A.Hill & R.Wetherbee, 1990

Holotype species: Guillardia theta D.R.A.Hill & R.Wetherbee

Original publication and holotype designation: Hill, D.R.A. & Wetherbee, R. (1990). Guillardia theta gen. et sp. nov. (Cryptophyceae). Canadian Journal of Botany 68: 1873-1876.

Precise date of publication: 3 Oct 1990

Description: Free-swimming, perpetually motile, elliptic, biflagellate monads; the furrow-gullet system consisting of a tubular gullet extending posteriorly from the subapical vestibulum, there is no furrow, the gullet being lined with usually two to four longitudinal rows of ejectisomes; with a single chloroplast, pyrenoid and nucleomorph, the chloroplast with the phycobiliprotein Cr-phycoerythrin 545, and varying in color from orange to red-brown, fading to yellow in older cells. Sexual reproduction is unknown, reproduction being by simple cell division. Cysts are unknown and palmelloid colonies not formed. The ultrastructure has been examined. The periplast structure is somewhat unusual, consisting of an inner component sheet that is closely appressed to the plasma membrane. The superficial component consists of long longitudinally oriented plates composed of minute subunits. The nucleomorph is not associated with the pyrenoid. The pyrenoidal matrix is not traversed by thylakoids. The rhizostyle consists of a curved band of microtubules possessing keels running down the ventral surface. Guillardia theta was isolated from Milford Harbour, Connecticut and is only known from that locality. It appears to have an absolute growth requirement for nitrogen in an ammonium form.

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.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=45028

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 22 November 2024