Chlorosaccus Luther, 1899
Holotype species: Chlorosaccus fluidus Luther
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Ott, D.W. & Oldham-Ott, C.K. (2003). Eustigmatophyte, Raphidophyte, And Tribophyte. In: Freshwater Algae of North America, Ecology and Classification. (Wehr, J.D. & Sheath, R.G. Eds), pp. 423-470. San Diego: Academic Press.
Description: Pale green colonial organism up to 15 cm long, organized in an irregularly shaped sac, nearly spherical, at times very irregular, leaf-like when old, often torn and perforated in places. Young thalli are attached to a substrate and become detached in order to float while growing. The mucilaginous surface often has "bumps" or very numerous hemispherical to conical protrusions, giving the mucilaginous surface a characteristic aspect in profile view. In certain cases, the "bumps" are reduced to a wart-like state, or even absent. In others they can be very long and branched. Cells 7-12 µm long and 3-8 µm wide, always located at the edge of the thallus, their large axis being perpendicular to the mucilaginous surface and their narrow axis being turned toward the outside. When they are in the protrusions, they are sometimes single, sometimes in twos or even fours. They possess a mucilaginous, clear, sometimes stratified coating, very often visible only after staining. Cells are spherical, ellipsoid-spherical, but also and most often ellipsoid to pear-shaped. Cell wall is very delicate, smooth and colorless. Generally, two chloroplasts, less often three or four, sometimes even eight, parietal, discoid to cup-shaped, without pyrenoids, Fatty and oily granules as storage products. Vegetative reproduction by autospores or zoospores. The latter develop singly or in pairs in isolated cells. They are ellipsoid to pear-shaped, often slightly concave and morphologically very variable. They have two unequal flagella. The larger (length 10 -14 µm) points forward while the other (length 4 - 5 µm) points backwards. The zoospores have two pale green, parietal, chloroplasts, without stigmata and contractile vacuoles. The zoospores quickly stop swimming, surround themselves with mucilage and develop a new thallus. Autospores are formed in twos and fours and remain inside the parental cell wall enveloped by a clear mucilage. There are also resting stages or akinetes which are formed by enlargement of certain cells and by thickening of cell walls. They are ovoid (length 8 -14 µm; width 7-10 µm). Chlorosaccus in freshwater in ditches and small streams; known only from northern Europe.
Information contributed by: A. Couté. The most recent alteration to this page was made on 18 Feb 2005 by Robert Wilkes.
Numbers of names and species: There are 3 species names in the database at present, of which 1 has 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):
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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: 23 April 2002 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=44174
Please cite this record as:
Guiry, M.D. & Guiry, G.M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 20 November 2018.