Dictyosphaerium Nägeli, 1849
Holotype species: Dictyosphaerium ehrenbergianum Nägeli
Original publication and holotype designation: Nägeli, C. (1849). Gattungen einzelliger Algen, physiologisch und systematisch bearbeitet. Neue Denkschriften der Allg. Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften 10(7): i-viii, 1-139, pls I-VIII.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Tsarenko, P.M. (2011). Trebouxiophyceae. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 61-108. Ruggell: A.R.A. Gantner Verlag K.-G..
According to Krienitz et al. (2011), the Dictyosphaerium-like taxa of Mychonastes form a monophyletic clade in the Chlorophyceae. Other species of Dictyosphaerium, including the type (D. ehrenbergianum belong to the Chlorellales (Trebouxiophyceae). - (2 Mar 2011) - Wendy Guiry
Description: Thalli forming free-floating, spherical to irregular colonies with 4 to 64 cells embedded in a common envelope, 10-100 µm in diameter. Cells perpendicular to colony surface, attached to the ends of thin stalks emerging from center of colony and branching dichotomously or tetrachotomously. Cells spherical to oval to ellipsoid or cylindrical, 1-10 µm in diameter or length. Cell walls typically smooth, roughened in one species; spines absent. Cells uninucleate; chloroplasts parietal and cup-shaped, generally single in vegetative cells, often two in mature or dividing cells; pyrenoids single per chloroplast. Asexual reproduction by autospores, 2 or mostly 4 per sporangium. Mother cells typically divide in two perpendicular planes also perpendicular to thallus surface. Spores release after rupture of parental cell and become attached to parental wall remnants; cell wall remnants develop into mucilaginous stalks. Large colonies result from multiple cycles of autospore formation. Zoospores reported by some early authors but poorly documented and considered absent by recent specialists. Sexual reproduction oogamous, reported only in D. indicum. Male gamete elongate with two apical flagella. Dictyosphaerium common and probably cosmopolitan in a variety of freshwater habitats soil. In eutrophic reservoirs and fishponds green water blooms may occur. At the end of the growing season colonies break up, forming single cells that later regenerate new thalli. Specialized dilute and low pH media have been developed for growth of particular Dictyosphaerium spp. A segregate genus, Pseudodictyosphaerium, characterized by the absence of pyrenoids. Emended by Bock et al. (2011: 640).
Information contributed by: F. Hindák & D. Garbary. The most recent alteration to this page was made on 20 Dec 2011 by M.D. Guiry.
Numbers of names and species: There are 31 species names in the database at present, as well as 12 infraspecific names. Of the species names, 11 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is 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):
Click here to also show infraspecific names in the list below.
Cambra Sánchez, J., Álvarez Cobelas, M. & Aboal Sanjurjo, M. (1998). Lista florística y bibliográfica de los clorófitos (Chlorophyta) de la Península Ibérica, Islas Baleares e Islas Canarias. pp. 1-614. Burgos: Asociación Española de Limnología.
Bock, C., Pröschold, T. & Krienitz, L. (2011). Updating the genus Dictyosphaerium and description of Mucidosphaerium gen. nov. (Trebouxiophyceae) based on morphological and molecular data. Journal of Phycology 47(3): 638-652.
Sluiman, H.J., Guihal, C. & Mudimu, O. (2008). Assessing phylogenetic affinities and species delimitations in Klebsormidiales (Streptophyta): nuclear-encoded rDNA phylogenies and ITS secondary structure models in Klebsormidium, Hormidiella, and Entransia. Journal of Phycology 44(1): 183-195.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 11 April 2002 by M.D. Guiry
Verified by: 20 December 2011 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43503
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 19 January 2019.