Eudorina Ehrenberg ex Ralfs, 1832: 78
Classification:
Empire Eukaryota
Kingdom Plantae
Subkingdom Viridaeplantae
Phylum Chlorophyta
Class Chlorophyceae
Order Volvocales
Family Volvocaceae
Holotype species: Eudorina elegans Ehrenberg
Original publication and holotype designation: Ehrenberg, C.G. (1832). Über die Entwickelung und Lebensdauer der Infusionsthiere; nebst ferneren Beiträgen zu einer Vergleichung ihrer organischen Systeme. Abhandlungen der Königlichen Akademie Wissenschaften zu Berlin, Physikalische Klasse 1831: 1-154.
Taxonomic status: currently recognized as a distinct genus.
Description: Colonies ovoid, ellipsoidal or cylindrical, containing 16 or 32 cells arranged radially in the periphery of a gelatinous matrix, forming a hollow sphere. The matrix does or does not form individual sheaths (species dependent) . Cells ovoid or spherical, each with two equal flagella, a stigma, two contractile vacuoles at the base of flagella, and a massive cup-shaped chloroplast with one (basal) or multiple pyrenoids. Stigmata of anterior cells larger than in posterior cells. No differentiation between somatic and reproductive cells occurs except for E. illinoisensis, in which the anterior four cells are small and facultatively somatic. Asexual reproduction by autocolony formation, each cell of the colony dividing successively to form a plakea, which becomes a daughter colony after inversion. Sexual reproduction anisogamous and produces walled aplanozygotes. Cells of colony divide successively to form sperm packets (bundles of male gametes), or develop into female gametes without cell division. Upon germination, zygotes give rise to a single or two biflagellate gone cells.
Comments: Eudorina is cosmopolitan in freshwater; E. elegans is among the most encountered species of green algae. Eudorina initially included only E. elegans; later seven more species were described. Comparative morphology and sexuality in Eudorina and Pleodorina studied using 73 clones from 44 natural populations to evaluate taxonomic characters at specific and infraspecific levels. Pleodorina included in Eudorina based on sexual compatibility between P. illinoisensis (E. illinoisensis) and three Eudorina species (including E. elegans), and on the transformation from somatic to reproductive cells in P. californica in some experimental conditions. Pleodorina and Eudorina are now distinguished based on the presence or absence, respectively, under normal conditions, of obligately somatic cells. Various studies have been carried out on Eudorina species including, ultrastructure of colony development and stigmata, experiments on synchronous populations and genetic analysis.
NCBI Nucleotide Sequences
Numbers of names and species: There are 15 species (and infraspecific) names in the database at present, of which 5 have been flagged as currently accepted taxonomically.
Names: ('C' indicates a name that is currently accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Eudorina californica (Shaw) Goldstein S
Eudorina charkowiensis (Korschikoff) Pascher S
Eudorina cylindrica Korshikov P
Eudorina echida Swirenko C
Eudorina elegans Chodat S
Eudorina elegans Ehrenberg C - type
Eudorina elegans var. wallichii W.B.Turner C
Eudorina elegans var. richmondiae Playfair C
Eudorina illinoisensis (Kofoid) Pascher C
Eudorina indica Iyengar S
Eudorina minodii (R.Chodat) H.Nozaki & L.Krienitz P
Eudorina peripheralis (Goldstein) T.K.Yamada C
Eudorina stagnale Wolle S
Eudorina unicocca var. peripheralis Goldstein S
Eudorina unicocca G.M.Smith C
Information contributed by: H. Nozaki. The most recent alteration to this page was made on 7 May 2010 by M.D. Guiry.
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.
