Platydorina Kofoid, 1899
Holotype species: Platydorina caudata Kofoid
Original publication and holotype designation: Kofoid, C.A. (1899). Plankton studies. III. On Platydorina, a new genus of the family Volvocidae, from the plankton of the Illinois River. Bulletin of the Illinois State Laboratory of Natural History 5(9): 419-440, pi. 38.
Description: Colonies flattened, slightly twisted and horseshoe-shaped with three to five posterior projections, each colony containing 16 or 32 cells arranged in one layer and oriented in different directions in a gelatinous matrix. Cells spherical or pear-shaped, each with two equal flagella, a stigma, two contractile vacuoles at the base of flagella and a massive cup-shaped chloroplast with a single basal pyrenoid. Asexual reproduction by autocolony formation, each cell of the colony dividing successively to form a plakea, which becomes a daughter colony after inversion and subsequent intercalation. Sexual reproduction anisogamous with sperm packets (bundles of male gametes). Platydorina is a freshwater genus only found in USA. Effects of various vitamins, nitrogen and carbon sources and pH on growth were investigated; only vitamin B12 stimulated growth, and a carbon source was required for anaerobic growth. A sulfated polysaccharide present in gelatinous matrix. Ultrastructure of flagellar apparatus suggested that Platydorina evolved from a Chlamydomonas-like ancestor.
Information contributed by: H. Nozaki. The most recent alteration to this page was made on 2010-05-14 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Verification of Data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera,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=44578
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 14 May 2010. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 26 November 2024
